17th International Conference on Topics in Astroparticle and Underground Physics (TAUP 2021)
TAUP 2021 was hosted by IFIC, a joint research centre shared by the Spanish Research Council (CSIC) and the University of Valencia (UV), in collaboration with other national institutions involved in astroparticle physics.
The biennial TAUP series covers recent experimental and theoretical developments in astroparticle physics by invited plenary review talks, parallel workshop sessions of invited and contributed presentations, and poster sessions.
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Welcome and Opening remarks 30mSpeakers: Mariam Tórtola (IFIC (CSIC-Univ. Valencia)), Sergio Pastor (IFIC (CSIC-Univ. Valencia))
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Neutrino theory 30m
Chair: Sandhya Choubey
Speaker: Raymond R. Volkas (Univ Melbourne) -
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Solar and geoneutrinos 30m
Chair: Sandhya Choubey
Speaker: Livia Ludhova (Forschungszentrum Juelich and RWTH Aachen) -
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Break 30m
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Long-baseline neutrino oscillations review (including future) 30m
Chair: Carlo Giunti
Speaker: Patricia Vahle (College of William and Mary) -
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Coherent elastic neutrino-nucleus scattering 30m
Chair: Carlo Giunti
Speaker: Carla Bonifazi (ICAS - ICIFI - UNSAM / CONICET)
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Hot topic Cosmology
Chair: Gabriela Barenboim
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Testing fundamental cosmological assumptions with Euclid 15m
The forthcoming Euclid survey will be able to map the Large Scale Structure with unprecendent precision, with the aim of tightly constraining the standard cosmological model and its most common extensions. The great sensitivity of Euclid can however also be exploited to test our most fundamental assumptions at the basis of the cosmological investigation.
In this talk I will present two recents results of the Euclid Collaboration, where forecast Euclid products are used alongside data from other surveys to constrain violation of the Distance Duality Relation and time evolution of the fine structure constant. I will show how Euclid will significantly contribute in constraining these effects, both connected with the presence of new physics beyond the standard cosmological model.Speaker: Matteo Martinelli (IFT, UAM/CSIC) -
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Cosmology meets functional QCD: First-order cosmic QCD transition induced by large lepton asymmetries 15m
The lepton flavour asymmetries of the Universe are observationally almost unconstrained before the onset of neutrino oscillations. We calculate the cosmic trajectory during the cosmic QCD epoch in the presence of large lepton flavour asymmetries. By including QCD thermodynamic quantities derived from functional QCD methods in our calculation our work reveals for the first time the possibility of a first-order cosmic QCD transition. We specify the required values of the lepton flavour asymmetries for which a ?rst-order transition occurs for a number of different benchmark scenarios.
Speaker: Isabel M. Oldengott (UC Louvain) -
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TeV-scale Lepton Number Violation: Connecting Leptogenesis, Neutrinoless Double Beta Decay, and Colliders 15m
In the context of TeV-scale lepton number violating (LNV) interactions, we illustrate the interplay between leptogenesis, neutrinoless double beta (0νββ) decay, and LNV searches at proton-proton colliders. Using a concrete model for illustration, we identify the parameter space where standard thermal leptogenesis is rendered unviable due to washout processes and show how 0νββ decay and pp-collisions provide complementary probes. We find that the new particle spectrum can have a decisive impact on the relative sensitivity of these two probes.
Speaker: Julia Harz (Technical University of Municht (TUM))
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Hot topic Dark Matter: 1
Chairs: Susana Cebrián (1), Riccardo Catena (2), Roberto Santorelli (3)
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The electronic recoil excess in XENON1T and the prospect to decipher it with XENONnT 15m
The XENON1T dark matter experiment, operated at the INFN Laboratori Nazionali del Gran Sasso, achieved the lowest electronic recoil background among all dark matter experiments, which is $76 \pm 2\,\mathrm{events}/(\mathrm{t}\cdot\mathrm{y}\cdot\mathrm{keV})$ below 30 keV. An excess of electronic recoils was found below 7 keV and most prominent between 2 and 3 keV. The excess could be induced by solar axions, solar neutrinos with an enhanced magnetic moment, or a trace amount of tritium background which could not be confirmed nor rejected. Consistent results were obtained by using ionization signals only, an approach which is more sensitive at low energies. XENONnT, the upgraded version of XENON1T, features a factor of 3 larger active mass and a factor of 6 reduced background, and thus will be more sensitive to low-energy electronic recoils. In this talk, I will review the excess electronic recoils in XENON1T and present the prospect to decipher the origin of the excess with data from XENONnT.
Speaker: Jingqiang Ye (Columbia University) -
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Status of the DEAP-3600 experiment 15m
DEAP-3600 is a single-phase liquid argon (LAr) dark matter detector operating 2 km underground at SNOLAB in Sudbury, Canada. The detector consists of 3.3 tonnes of LAr in a spherical acrylic vessel viewed by an array of 255 photomultiplier tubes. DEAP-3600 has been taking data stably since November 2016. DEAP-3600 is sensitive to nuclear recoils from dark matter particles, which cause the emission of prompt scintillation light. While DEAP-3600 demonstrated excellent performance and holds the leading WIMP exclusion among LAr detectors, its sensitivity is limited by backgrounds induced by alpha activity at the LAr inlet, in a shadowed region of detector. The upcoming hardware upgrade of the detector aims at fixing that limitation and, in consequence, at reaching the full WIMP sensitivity. This talk presents the latest results from DEAP-3600, the status of the ongoing physics analyses, as well as of the hardware upgrade. Plans for the following physics run will also be discussed.
Speaker: Marcin Kuźniak (AstroCeNT / CAMK PAN) -
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Building, calibrating and searching for WIMPs and reactor CEvNS with Scintillating Bubble Chambers 15m
The Scintillating Bubble Chamber (SBC) Collaboration is rapidly developing liquid-noble bubble chambers to detect sub-keV nuclear recoils. Demonstrations in liquid xenon at the few-gram scale have confirmed that this technique combines the event-by-event energy resolution of a liquid-noble scintillation detector with the world-leading electron-recoil discrimination capability of the bubble chamber, and in fact maintains that discrimination capability at much lower thresholds than traditional Freon-based bubble chambers. The promise of unambiguous identification of sub-keV nuclear recoils in a scalable detector makes this an ideal technology for both GeV-mass WIMP searches and CEvNS detection at reactor sites. We will present calibration results from the xenon chamber, progress in building SBC's first 10-kg liquid argon bubble chamber at Fermilab, WIMP sensitivity projections for a dark matter search at SNOLAB, and CEvNS science and site selection studies at reactors in Mexico.
Speaker: Rocco Coppejans (Northwestern University)
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Hot topic Neutrinos: 1
Chairs: Silvia Capelli (1), Ninetta Saviano (2)
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The KATRIN experiment: neutrino mass measurements with sub-eV sensitivity 15m
The KArlsruhe TRItium Neutrino experiment (KATRIN) is searching for the signature of the neutrino mass in the endpoint region of the tritium beta-decay spectrum. KATRIN combines a high-intensity gaseous molecular tritium source with a high-resolution spectroscopy using electrostatic filter with magnetic adiabatic collimation to reach the target neutrino-mass sensitivity of 0.2 eV/$c^2$, improving on the previous measurements by an order of magnitude. With the first science run of KATRIN the previous neutrino mass bounds were improved by a factor of two, with the first upper limit of 1.1 eV/$c^2$ (90% CL).
In this talk an overview of the KATRIN experiment and its very recent results are presented. Our new results reaching a sub-eV neutrino-mass sensitivity based on the whole 2019 data-set will be discussed. In addition, the talk reports on the KATRIN exploration of interesting BSM physics cases and closes with an outlook on the future prospects of KATRIN.
Speaker: Alexey Lokhov (University of Muenster & INR, Troitsk) -
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Project 8: the path to improved neutrino mass 10m
Project 8 is a direct neutrino mass experiment that has developed a new technique, Cyclotron Radiation Emission Spectroscopy (CRES), to make a differential measurement of the tritium $\beta^{-}$ spectrum. Project 8 aims to use the advantages of CRES to surmount the systematic and statistical limitations of current-generation direct neutrino mass measurement methods, proceeding in a phased approach toward a goal of effective electron antineutrino mass sensitivity of ${\sim}$40 meV/c$^2$ using atomic tritium. This talk will report on the progress toward Phase III free-space CRES and atomic tritium demonstrations, which will enable the advances in energy resolution and statistics needed to achieve full Phase IV sensitivity.
This work is supported by the US DOE Office of Nuclear Physics, the US NSF, the PRISMA+ Cluster of Excellence at the University of Mainz, and internal investments at all institutions.
Speaker: Elise Novitski (University of Washington) -
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Neutrino mass determination with Holmium-163 - the ECHo experiment 10m
The Electron Capture in $^{163}$Ho experiment, ECHo, is a running experiment for the determination of the neutrino mass scale via the analysis of the end point region of the $^{163}$Ho electron capture spectrum. In the first phase, ECHo-1k, about 60 MMCs pixels enclosing $^{163}$Ho ions for an activity of about 1Bq per pixel have been operated for several months. The goal of this first phase is to reach a sensitivity on the effective electron neutrino mass below 20 eV/c$^2$ by the analysis of a $^{163}$Ho spectrum with more than 10$^8$ events. We discuss the characterization of the single pixel performance and the stability over the measuring period. Results from the analysis of the acquired data will be presented with focus on data reduction efficiency and on the procedures to obtain the final high statistics spectrum. A preliminary analysis of the $^{163}$Ho spectral shape will be described and the expected sensitivity on the effective electron neutrino mass, on the basis of the properties of the presented spectrum, will be discussed. In conclusion, we will present how the performance obtained by the MMC arrays used during the first phase of the ECHo experiment have led to the design of the MMC arrays for the second phase, ECHo-100K. In ECHo-100k about 12000 MMC pixels each hosting $^{163}$Ho for an activity of 10 Bq will be simultaneously operated thanks to the microwave SQUID multiplexing readout. Operating these arrays for three years will allow for reaching a sensitivity on the electron neutrino mass at the 1 eV/c$^2$ level.
Speaker: Loredana Gastaldo (Kirchhoff-Institute for Physics, Heidelberg University) -
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HOLMES: progresses towards a calorimetric neutrino mass measurement with eV scale mass sensitivity 10m
The assessment of the absolute neutrino mass scale is still a crucial challenge in today’s particle physics and cosmology. Beta or electron capture decay spectra end-point measurements are currently the only experimental methods which can provide a model-independent measurement of the absolute neutrino mass scale.
While KATRIN is successfully pushing the mass sensitivity below 1 eV, there is a strong need for radically different direct experiments to confirm and strengthen present and future KATRIN's results. $^{163}$Ho electron capture calorimetric experiments are among the best candidates for this task. In calorimetric measurements, the energy released in the decay process is entirely contained into the detector, except for the fraction carried away by the neutrino: this provides an independent direct measurement that has completely different systematic uncertainties. The most suitable detectors for this type of measurement are low-temperature thermal detectors, where all the energy released in an absorber is converted into a temperature increase that can be measured by a sensitive thermometer directly coupled with the absorber. HOLMES will deploy a large array of low temperature microcalorimeters with ion-implanted $^{163}$Ho nuclei.
The ultimate goal of HOLMES is a statistical neutrino mass sensitivity of 1 eV to be achieved with an array of 1000 pixels, each with a $^{163}$Ho ion-implanted activity of about 300 Bq. As a near-term goal, HOLMES is preparing to ion-implant a lower dose to give an activity of a few Bequerels per pixel. A measurement with such an array is planned to begin by 2021 and will provide a sensitivity of less than 10 eV.
In this contribution we outline the HOLMES project with its physics reach and technical challenges, along with its status and prospects. In particular, we will present the status of HOLMES activities aiming at the production of the first low-dose ion-implanted TES array and at the first neutrino mass measurement campaign. We will also discuss the prospects and strategies for a future $^{163}$Ho experiment with a sub-eV neutrino mass sensitivity.Speaker: Angelo Nucciotti (Dipartimento di Fisica, Università di Milano-Bicocca, Milano, Italy)
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Double beta decay: theory review 30m
Chair: Martin Hirsch
Speaker: Frank Deppisch (University College London) -
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Double beta decay: experimental review 30m
Chair: Martin Hirsch
Speaker: Andrea Giuliani (IJCLab, U Paris-Saclay, Orsay) -
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Break 30m
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Supernovae: neutrinos and gravitational waves 30m
Chair: Junpei Shirai
Speaker: Kei Kotake (Fukuoka University) -
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Reactor experiments review (including short-baseline) 30m
Chair: Junpei Shirai
Speaker: Cécile Jollet (Univ Bordeaux) -
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Review on underground laboratories 30m
Chair: Junpei Shirai
Speaker: Ezio Previtali (Univ Milano Bicocca & Gran Sasso Lab)
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Inflation overview 30m
Chair: Olga Mena
Speaker: Richard Easther (Univ Auckland) -
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Cosmology overview 30m
Chair: Olga Mena
Speaker: Licia Verde (ICC, IEEC-Univ Barcelona - ICREA) -
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Break 30m
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Dark matter and structure formation 30m
Chair: Martina Gerbino
Speaker: Matteo Viel (SISSA Trieste) -
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Multimessenger astronomy 30m
Chair: Martina Gerbino
Speaker: Andrii Neronov (APC Paris & Univ Geneve) -
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Discussion Panel Cosmology 1
Chair: Savvas Nesseris
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A numerical approach to stochastic inflation and primordial black holes 15m
Quantum fluctuations created during cosmic inflation act as seeds of all structure in the universe. The strongest fluctuations lead to the formation of primordial black holes, a dark matter candidate. I present a study where these fluctuations are analyzed numerically within the framework of stochastic inflation. This method allows us to probe nonperturbative effects and include backreaction between the fluctuations and the local background. The results reveal a non-Gaussian, exponential tail in the probability distribution of the fluctuations, enhancing black hole production by a factor of $10^5$ compared to a Gaussian estimate in our CMB-compatible example scenario. The same method may be used to improve the primordial black hole predictions of any inflationary model.
Speaker: Eemeli Tomberg (NICPB, Tallinn) -
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Axion Production in Pulsar Magnetosphere Gaps 15m
Pulsar magnetospheres admit non-stationary vacuum gaps that are characterized by non-vanishing $\bf {E \cdot B}$. The vacuum gaps play an important role in plasma production and electromagnetic wave emission. We show that these gaps generate axions whose energy is set by the gap oscillation frequency. The density of axions produced in a gap can be several orders of magnitude greater than the ambient dark matter density. In the strong pulsar magnetic field, a fraction of these axions may convert to photons, giving rise to broadband radio signals. We show that dedicated observations of nearby pulsars with radio telescopes (FAST) and interferometers (SKA) can probe axion-photon couplings that are a few orders of magnitude lower than current astrophysical bounds.
Speaker: Anirudh Prabhu (Stanford University) -
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An update on the two singlet Dark Matter model 15m
We revisit the two real singlet extension of the Standard Model with a $Z_2\times Z_2^\prime$ symmetry. One of the singlet scalars $S_2$, by virtue of an unbroken $Z_2^\prime$ symmetry, plays the role of a stable dark matter candidate. The other scalar $S_1$, with spontaneously broken $Z_2$-symmetry, mixes with the SM Higgs boson and acts as the scalar mediator. We analyze the model by putting in the entire set of theoretical and recent experimental constraints. The latest bounds from direct detection Xenon1T experiment severely restricts the allowed region of parameter space of couplings. To ensure the dark matter satisfies the relic abundance criterion, we rely on the Breit-Wigner enhanced annihilation cross-section. Further, we study the viability of explaining the observed gamma-ray excess in the galactic center in this model with a dark matter of mass in the $\sim 36-51$ GeV window and present our conclusions.
Speaker: Tanushree Basak (Indus University) -
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Exploring the Sun's core with BabyIAXO 15m
Axions are a natural consequence of the Peccei-Quinn mechanism, the most compelling solution to the strong-CP problem. Similar axion-like particles (ALPs) also appear in a number of possible extensions of the Standard Model, notably in string theories. Both axions and ALPs are very well motivated candidates for Dark Matter, and in addition, they would be copiously produced at the sun’s core. A relevant effort during the last decade has been the CAST experiment at CERN, the most sensitive axion helioscope to-date. The International Axion Observatory (IAXO) is a large-scale 4th generation helioscope. As its primary physics goal, IAXO will look for solar axions or ALPs with a signal to background ratio of about 5 orders of magnitude higher than CAST.
In this talk I will briefly review astrophysical hints and models that we will be able to explore while searching for solar axions within the context of the IAXO helioscope search program, and in particular the physics under reach of BabyIAXO, and intermediate helioscope stage towards the full IAXO.
Speaker: Javier Galan (Universidad de Zaragoza) -
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Maximally misaligned axions 15m
In this talk I will discuss a simple model of maximal axion misalignment. Maximally-misaligned axions with masses larger than 10^{-22} eV constitute an attractive DM candidate with interesting phenomenology. On the other hand, maximally-misaligned axions with masses m=O(1-100)H_0 generically behave as dark energy with a decay constant that can take values well below the Planck scale, avoiding problems associated to super-Planckian scales.
Speaker: Mario Reig (IFIC (CSIC-Univ Valencia)) -
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Resurrecting the Fraternal Twin WIMP Miracle 15m
In Twin Higgs models which contain the minimal particle content required to address the little hierarchy problem (i.e. fraternal models), the twin tau has been identified as a promising candidate for dark matter. In this class of scenarios, however, the elastic scattering cross section of the twin tau with nuclei exceeds the bounds from XENON1T and other recent direct detection experiments. In this paper, we propose a modification to the Fraternal Twin Higgs scenario that we call $\mathbb{Z}_2$FTH, incorporating visible and twin hypercharged scalars (with $Y=2$) which break twin electromagnetism. This leads to new mass terms for the twin tau that are unrelated to its Yukawa coupling, as well as additional annihilation channels via the massive twin photon. We show that these features make it possible for the right-handed twin tau to freeze out with an acceptable thermal relic abundance while scattering with nuclei at a rate that is well below existing constraints. Nonetheless, large portions of the currently viable parameter space in this model are within the reach of planned direct detection experiments. The prospects for indirect detection using gamma rays and cosmic-ray antiprotons are also promising in this model. Furthermore, if the twin neutrino is light, the predicted deviation of $\Delta N_{\mathrm{eff}}\sim 0.1$ would be within reach of Stage 4 CMB experiments. Finally, the high luminosity LHC should be able to probe the entire parameter space of the $\mathbb{Z}_2$FTH model through charged scalar searches. We also discuss how searches for long-lived particles are starting to constrain Fraternal Twin Higgs models.
Speaker: Jakub Scholtz (U degli studi di Torino) -
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Thermal axions with multi-eV masses are possible in low-reheating scenarios 15m
We revise cosmological mass bounds on hadronic axions in low-reheating cosmological scenarios, with a reheating temperature $T_{\rm RH}\le 100$ MeV, in light of the latest cosmological observations. In this situation, the neutrino decoupling would be unaffected, while the thermal axion relic abundance is suppressed. Moreover, axions are colder in low-reheating temperature scenarios, so that bounds on their abundance are possibly loosened. As a consequence of these two facts, cosmological mass limits on axions are relaxed. Using state-of-the-art cosmological data and characterizing axion-pion interactions at the leading order in chiral perturbation theory, we find in the standard case an axion mass bound $m_a < 0.26$ eV. However, axions with masses $m_a \simeq 1$ eV, or heavier, would be allowed for reheating temperatures $T_{\rm RH}<80$ MeV. Multi-eV axions would be outside the mass sensitivity of current and planned solar axion helioscopes and would demand new experimental approaches to be detected.
Speaker: Pierluca Carenza (Bari University & INFN Bari)
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Discussion Panel Dark Matter 1
Chair: María Luisa Sarsa
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DARWIN - a future dark matter and neutrino physics observatory 15m
DARWIN is a planned 50 ton liquid xenon time-projection-chamber with the primary goal of searching directly for dark matter. It aims to measure nuclear recoils induced by Weakly Interacting Massive Particles (WIMPs) down to WIMP-nucleon cross sections of 1e-48 cm2 at which neutrinos become an irreducible background.
Thanks to its low energy threshold at a few keV, its ultra-low expected background levels, and unprecedented large target mass, further physics measurements become feasible. Those include the observation of pp-solar neutrinos, coherent neutrino-nucleus interactions, eventually supernova neutrinos, the search for axions or for rare processes like the neutrinoless double-beta decay of 136Xe. The talk will summarise the physics goals of DARWIN which are driving its design. In addition, an overview of the baseline detector setup and on-going R&D activities will be given.
Speaker: Teresa Marrodán Undagoitia (Max-Planck-Institut für Kernphysik, Heidelberg, Germany) -
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Status of the LUX-ZEPLIN (LZ) experiment 15m
LUX-ZEPLIN (LZ) is a dark matter direct detection experiment currently being commissioned at the Sanford Underground Research Facility (SURF) in Lead, South Dakota. The experiment utilizes a two-phase time projection chamber (TPC) to look for dark matter interactions. The active region of the detector consists of 7 tonnes of liquid xenon with a 5.6 tonne fiducial volume, and is expected to significantly improve our experimental sensitivity to dark matter beyond existing limits set by previous experiments. In this talk, I will give an overview of the LZ project and describe the current status of the experiment, which is expected to start taking science data this year.
Speaker: David Woodward (Penn State University) -
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Physics Reach of the LUX-ZEPLIN Experiment 15m
LUX-ZEPLIN (LZ) is a direct dark matter detection experiment currently being commissioned at the 4850’ level of the Sanford Underground Research Facility in Lead, South Dakota. The detector comprises a position sensitive xenon time projection chamber surrounded by an instrumented xenon “skin” and liquid scintillator active vetoes. An active mass of 7 tonnes of xenon is used, from which a fiducial region of mass 5.6 tonnes is formed that has minimal gamma-ray and neutron activity. The radiopure environment has been further ensured through an extensive material screening and selection campaign, together with in-house xenon purification. These background mitigation strategies underpin LZ’s unprecedented projected sensitivity to WIMPs, down to a spin-independent cross section of 1.4 x 10^-48 cm^2 for a 40 GeV/c^2 mass in 1000 live days. This talk will provide an overview of the science reach of the LZ experiment, not just for WIMPs but also for other new physics.
Speaker: Amy Cottle (University of Oxford) -
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A look at the PandaX-4T commissioning data 15m
After PandaX-II experiment, we started to build PandaX-4T detector with 4 ton liquid xenon in the sensitive volume at China Jinping Underground laboratory. PandaX-4T experiment has completed detector construction, and detector commissioning has begun since the end of the year 2020. Through the commissioning, we are optimizing the detector operation conditions, testing various calibration sources including the newly installed DD neutron source, developing detector response model and signal reconstruction algorithm. In this talk, I will give an overview of the commissioning data and detector performance.
Speaker: Yi Tao (Shanghai Jiao Tong University) -
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Acoustic response of nuclear recoils in bubble chambers 15m
The bubble chambers of the PICO collaboration use the acoustic signal generated from nucleations to classify nuclear recoil events from alpha decays in the bulk fluid. The success of these detectors in probing the potential WIMP-proton cross section comes in part from the low energy threshold that can be achieved. This nucleation threshold, based on the Seitz model, is dependent on fluid type, pressure, and temperature. At higher thresholds bubble nucleation does occur but with a significant loss in the measurable acoustic signal. To investigate this, the acoustic response of bulk nuclear recoil events was measured as a function of pressure and temperature and found to depend exponentially on both parameters. Understanding the form of the acoustic response can be used to predict potential operating conditions for specific thresholds in future larger-scale superheated liquid detectors. Details of the measurement in a small-scale test setup and a comparison to existing data will be presented.
Speaker: Benjamin Broerman (Queen's University) -
17:45
DarkSide-20k and the Future Liquid Argon Dark Matter Program 15m
DarkSide run since mid-2015 a 50-kg-active-mass dual-phase Liquid Argon Time Projection Chamber (TPC), filled with low radioactivity argon from an underground source and produced world-class results for both the low mass (M_WIMP<20 GeV/c^2) and high mass (M_WIMP>100 GeV/c^2) direct detection search for dark matter.
The next stage of the DarkSide program will be a new generation experiment involving a global collaboration from all the current Argon based experiments. DarkSide-20k is designed as a 20-tonne fiducial mass dual-phase Liquid Argon TPC with SiPM based cryogenic photosensors and is expected to be free of any instrumental background for exposure of >100 tonne x year. Like its predecessor, DarkSide-20k will be housed at the INFN Gran Sasso (LNGS) underground laboratory, and it is expected to attain a WIMP-nucleon cross-section exclusion sensitivity of 7.4 x 10^{-48} cm^2 for a WIMP mass of 1 TeV/c^2 in a 200 t yr run. DarkSide-20k will be installed inside a membrane cryostat containing more than 700 t of liquid Argon and be surrounded by an active neutron veto based on a Gd-loaded acrylic shell. The talk will give the latest updates of the ongoing R&D and prototype tests validating the initial design.
A subsequent objective, towards the end of the next decade, will be the construction of the ultimate detector, ARGO, with a 300 t fiducial mass to push the sensitivity to the neutrino floor region for high mass WIMPs.Speaker: Emilija Pantic (UC Davis) -
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DEAP-3600 constraints on dark matter effective interactions and halo substructures 15m
The WIMP search in 231 live-days of data collected by the DEAP-3600 experiment showed no event candidates, resulting in a world-leading upper limit on the spin-independent dark matter-nucleon cross-section for an argon target. The present study reanalyzed that null result within a Non-Relativistic Effective Field Theory (NREFT) framework, and further examined the impact of potential dark matter halo substructures motivated by the observations of stellar distributions from the Gaia satellite and other astronomical surveys. Constraints were set on the coupling strength of the effective operators O1, O3, O5, O8, and O11, considering isoscalar, isovector, and xenonphobic scenarios, as well as on the NREFT-derived specific interactions: millicharge, magnetic dipole, electric dipole, and anapole. The effects of halo substructures on each of the operators was explored as well, showing that the O5 and O8 operators are particularly sensitive to the velocity distribution, even for heavy WIMPs.
Speaker: Ariel Zuñiga Reyes (Universidad Nacional Autónoma de México (UNAM)) -
17:45
Detection Of Heavy Dark Matter Particles In DEAP-3600 15m
DEAP-3600, hosted at SNOLAB, has been designed for the search of WIMPs, Weakly Interacting Massive Particles; its target of 3.3 t of liquid argon makes it the largest direct detection experiment. In addition to its sensitivity to WIMPs, DEAP-3600 is sensitive to super-massive dark matter candidates with masses up to the Planck scale. For particles with masses above 10^{16} GeV and cross-sections with argon above 10^{-24} cm^2, these dark matter particles are expected to reach an underground experiment and give a detectable signal in liquid argon. Due to the large cross-section, the expected signal in DEAP-3600 is a collinear sequence of nuclear recoils in the same acquisition window, giving a very distinguishable and unique signature; hence, we refer to them as Multi-Scattering Heavy Dark Matter Particles.
In this talk, the search for this candidate in three years of data-taking is presented, starting from the expected signal compared to the expected background, and Monte Carlo model developed; then, the results of the unblinding procedure will be presented.Speaker: Michela Lai (University of Cagliari) -
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Investigating WIMPs with XENONnT 15m
The multi-tonne XENONnT detector is the next step in the evolution of the XENON project. The experiment, aimed at direct detection of WIMPs, utilizes 5.9t of instrumented liquid xenon. Dedicated screening results of all detector materials were used to project the expected overall background in the detector, while improvements in suppressing intrinsic backgrounds from electronic recoil sources will allow XENONnT to reduce this background to an expected level 1/6th that of its predecessor within a 4t fiducial volume. The addition of a neutron veto around the XENONnT cryostat allows for significant suppression of the overall neutron background as well. XENONnT is aimed at achieving a 20 t.y exposure over its lifetime. In this talk I will present the sensitivity to spin-dependent and -independent WIMP nucleon interactions. In the case of spin-independent interactions, the sensitivity will reach a cross-section of $1.4\times10^{-48}\,\mathrm{cm}^2$ for a 50\,GeV/c$^2$ mass WIMP at 90% confidence level, more than one order of magnitude beyond the current best limits.
Speaker: Jacques Pienaar (University of Chicago) -
17:45
Measurement of the underground argon radiopurity for Dark Matter direct searches 15m
A major worldwide effort is underway to procure the radiopure argon needed for DarkSide-20k (DS-20k), the first large scale detector of the new Global Argon Dark Matter Collaboration. The Urania project will extract and purify underground argon (UAr) from CO2 wells in the USA at a production rate of about 300 kg/day. Additional chemical purification of the UAr will be required prior to its use in the DS-20k LAr-TPC. The Aria project will purify UAr using a cryogenic distillation column (Seruci-I), located in Sardinia (Italy). Assessing the UAr purity in terms of Ar-39 is crucial for the physics program of the DarkSide-20k experiment. DArT is a small (1 litre) radiopure chamber that will measure the Ar-39 depletion factor in the UAr. The detector will be immersed in the active liquid Ar volume of ArDM (LSC, Spain), which will act as a veto for gammas from the detector materials and the surrounding rock. In this talk, I will review the status and prospects of the UAr projects for DarkSide-20k.
Speaker: Vicente Pesudo (CIEMAT and LSC) -
17:45
Recent progress of PandaX-4T experiment 15m
PandaX-4T is a tonne-scale dark matter direct searching experiment, utilizing 4 tonne liquid xenon as target material in sensitive volume. The experiment is located at China Jinping Underground Laboratory, with overburden of 2400 meter water equivalent. Recently, the PandaX-4T experiment has finished assembling on site, and started commissioning of the sub-systems. In this talk, I will talk about the status and performances of major sub-systems of PandaX-4T as well as the ongoing commissioning runs.
Speaker: Qing Lin (University of Science and Technology of China) -
17:45
Search for Dark Matter with the PICO-500 Experiment 15m
The PICO collaboration searches for WIMPs using large superheated liquid detectors, or bubble chambers. Recent results from the complete exposure of the PICO-60 C$_3$F$_8$ detector at SNOLAB set the world’s most stringent limits on WIMP-proton spin-dependent interactions. I will present the current status of the construction and physics potential of the next generation, tonne-scale experiment at SNOLAB: PICO-500.
Speaker: Guillaume Giroux (Queen's University)
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Discussion Panel Dark Matter 2
Chair: Rebeca Gozzini
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Probing light dark matter particles with astrophysical experiments 15m
Strong bounds from direct detection experiment put stringent limit on the dark matter mass which forces us to go beyond WIMP model of dark matter. In recent years the light mass dark matter particles gain lots of attention among the particle physicists. In this talk I will discuss about light gauge bosons motivated from U(1) extension of standard model and axions which can be a possible dark matter candidates and its detection in several astrophysical experiments.
Speaker: Tanmay Kumar Poddar (Physical Research Laboratory) -
17:40
The Earth as a transducer for dark-photon dark-matter detection 15m
In this talk, I will propose the use of the Earth as a transducer for ultralight dark-matter detection. In particular I will point out a novel signal of kinetically mixed dark-photon dark matter: a monochromatic oscillating magnetic field generated at the surface of the Earth. Similar to the signal in a laboratory experiment in a shielded box (or cavity), this signal arises because the lower atmosphere is a low-conductivity air gap sandwiched between the highly conductive interior of the Earth below and ionosphere or interplanetary medium above. At low masses (frequencies) the signal in a laboratory detector is usually suppressed by the size of the detector multiplied by the dark-matter mass. Crucially, in our case the suppression is by the radius of the Earth, and not by the (much smaller) height of the atmosphere. The magnetic field signal exhibits a global vectorial pattern that is spatially coherent across the Earth, which enables sensitive searches for this signal using unshielded magnetometers dispersed over the surface of the Earth. I will summarize the results of such a search using a publicly available dataset from the SuperMAG collaboration. The constraints from this search are complementary to existing astrophysical bounds. Future searches for this signal may improve the sensitivity over a wide range of ultralight dark-matter candidates and masses.
Speaker: Saarik Kalia (Stanford University) -
17:45
Low Mass Black Holes from Dark Core Collapse 15m
Unusual masses of black holes being discovered by gravitational wave experiments pose fundamental questions about the origin of these black holes. Black holes with masses smaller than the Chandrasekhar limit $\approx$ 1.4 M$_\odot$ are essentially impossible to produce through stellar evolution. We propose a new channel for production of low mass black holes: stellar objects catastrophically accrete nonannihilating dark matter, and the small dark core subsequently collapses, eating up the host star and transmuting it into a black hole. The wide range of allowed dark matter masses allows a smaller effective Chandrasekhar limit and thus smaller mass black holes. We point out several avenues to test our proposal, focusing on the redshift dependence of the merger rate. We show that redshift dependence of the merger rate can be used as a probe of the transmuted origin of low mass black holes.
Speaker: Ranjan Laha (Indian Institute of Science, Bengaluru, India) -
17:45
Neutrino and Axion Astronomy with Dark Matter Experiments 15m
Beyond their unprecedented sensitivity to dark matter (DM), as I will demonstrate, large direct detection experiments constitute impressive neutrino telescopes. This opens a new window into astronomy, leading to possible insights into major problems such as the origin of supermassive black holes. Furthermore, DM experiments can be exploited as novel tools in multi-messenger astronomy for exploration of new physics. I will discuss detection of relativistic axions from transient astrophysical sources (e.g. axion star explosions), which can lead to new insights into the fundamental axion potential.
Speaker: Volodymyr Takhistov (Kavli IPMU, U. Tokyo) -
17:45
Radio-frequency Dark Photon Dark Matter across the Sun 15m
Dark photon as an ultralight dark matter candidate can interact with the Standard Model particles via kinetic mixing. We propose to search for the ultralight dark photon dark matter using radio telescopes with solar observations. The dark photon dark matter can efficiently convert into photons in the outermost region of the solar atmosphere, the solar corona, where the plasma mass of photons is close to the dark photon rest mass. Due to the strong resonant conversion and benefiting from the short distance between the Sun and the Earth, the radio telescopes can lead the dark photon search sensitivity in the mass range of $4 \times 10^{-8} - 4\times 10^{-6} \, \rm{eV}$, corresponding to the frequency $10 - 1000 \, {\rm MHz}$. As a promising example, the operating radio telescope LOFAR can reach the kinetic mixing $\epsilon \sim 10^{-13}$ ($10^{-14}$) within 1 (100) hour solar observations. The future experiment SKA phase 1 can reach $\epsilon \sim 10^{-16} - 10^{-14}$ with $1$ hour solar observations.
Speaker: Jia Liu (Peking University) -
17:45
Searching for a Dark Matter with the PADME experiment 15m
The evidence for the existence of dark matter, so far is based on its gravitational effects. Nevertheless, many theoretical models assume other non-gravitational very-weak interactions between dark matter and ordinary matter, and to test this hypothesis, different experiments are trying to directly detect dark matter signals at particle accelerators.
PADME (Positron Annihilation into Dark Matter Experiment) is peculiar since is searching for dark matter candidates, and in particular a dark photon, in the products of the annihilation of a positron beam with the electrons of an active target. This technique only requires that the dark photon couples to the ordinary one allowing to investigate its existence independently from its decay modes.
The experiment was build and commissioned at the Laboratori Nazionali di Frascati of INFN at the end of 2018 beginning of 2019, and collected in 2020 $\sim$ 5×10$^{12}$ positrons on target at 430 MeV.
The dark photon signal is searched by studying the missing-mass spectrum of single-photon final states resulting from the annihilation process. PADME is expected to reach a sensitivity up to $10^{-6}$ in $\epsilon^2$ (kinetic mixing coefficient) for low-mass dark photons ($\sim$ 20.MeV). Here we present the performance of the detector and the preliminary results of the ongoing analyses on SM final states: $\gamma \gamma$-events and positron Bremsstrahlung. Prospects for sensitivity to different dark sector candidates, ALPs and dark Higgs, will be also given.Speaker: Isabella Oceano (Salento U. and INFN, Lecce) -
17:45
Signatures of primordial black hole dark matter at DUNE and THEIA 15m
Primordial black holes (PBHs) are a potential dark matter candidate whose masses can span over many orders of magnitude. If they have masses in the 10^15 − 10^17 g range, they can emit sizeable fluxes of MeV neutrinos through evaporation via Hawking radiation. We explore the possibility of detecting light (non-)rotating PBHs with future neutrino experiments DUNE and THEIA. We will show that they will be able to set competitive constraints on PBH dark matter, thus providing complementary probes in a part of the PBH parameter space currently constrained mainly by photon data.
Speaker: Valentina De Romeri (IFIC (CSIC-Univ Valencia)) -
17:45
Signatures of Primordial Black Holes in theories of Large Extra Dimensions 15m
The addition of spatial dimensions compactified to submillimeter scales serves as an elegant solution to the hierarchy problem. As a consequence of the extra-dimensional theory, primordial black holes can be created by high-energy particle interactions in the early universe. While four-dimensional primordial black holes have been extensively studied, they have received little attention in the context of extra-dimensions. We adapt and extend previous analyses of four-dimensional primordial black holes for the purpose of studying the impact extra-dimensions have on cosmology. We find new constraints on both extra-dimensional primordial black holes, and the fundamental extra-dimensional theories by combining an analysis of Big Bang Nucleosynthesis, the Cosmic Microwave Background, the Cosmic X-ray Background, and the galactic centre gamma-rays. With these constraints we explore to what extent these extra-dimensional primordial black holes can comprise the dark matter in our universe.
Speaker: Avi Friedlander (Queen's University) -
17:45
Stellar Shocks from Dark Matter 15m
Macroscopic dark matter is almost unconstrained over a wide ``asteroid-like'' mass range, where it could scatter on baryonic matter with geometric cross section. When such an object travels through a star, it produces shock waves which reach the stellar surface, leading to a distinctive transient optical, UV and X-ray emission. I shall talk about how this signature can be searched for on a variety of stellar types and locations. In a dense globular cluster, such events occur far more often than flare backgrounds. Existing UV telescopes, like Hubble, could probe orders of magnitude in dark matter mass in one week of dedicated observation.
Speaker: Anirban Das (SLAC National Accelerator Laboratory) -
17:45
Studying QCD modeling of uncertainties in particle spectra from dark-matter annihilation into jets 15m
Motivated by various excesses observed by Fermi-LAT and AMS, we perform a detailed analysis of QCD uncertainties on particle spectra from dark-matter annihilation (or decay) into jets. When annihilated to SM particles, the final-state products undergo various complicated processes such as QED and QCD bremsstrahlung, hadronization, and hadron decays. These processes contain some intrinsic uncertainties which are usually difficult to model and which are neglected in physical analyses. First, we perform several re-tunings of the fragmentation function parameters. Then, we estimate two kinds of uncertainties: (i) perturbative from QCD showers and (ii) non-perturbative from hadronization function. The results are tabulated for a wide range of dark matter masses and annihilation channels. They can be found on Zenodo; https://doi.org/10.5281/zenodo.3764809
Speaker: Adil Jueid (Konkuk University)
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Discussion Panel HE astrophys. & CRs/Multi-messenger astronomy 1
Chair: Michela Negro
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Neutrinos from galactic sources 15m
The HAWC telescopes has recently revealed new spectra for gamma-ray sources in the Galactic plane. In this talk I will review the possibility of detecting these sources at KM3 detectors. I will consider, with particular emphasis, the 2HWC J1825-134 source. Amongst the HAWC sources, it is indeed the most luminous in the multi-TeV domain and therefore is one of the first that should be searched for with a neutrino telescope in the northern hemisphere. I will show the prospects to detect this source at the KM3NeT detector and comment on the possibilities for others neutrino telescopes.
I will consider, moreover, the gamma-ray sources eHWC J1907+063, eHWC J2019+368 and 2HWC J1857+027. For these sources, I will show the prediction for neutrinos at the IceCube detector, presenting the calculation of the statistical significance, considering 10 and 20 years of running time, and I will comment on the current results reported by the collaboration.Speaker: Viviana Niro (Laboratoire APC) -
17:25
Can unresolved PWNe weaken the evidence of CR spectral hardening in the inner Galaxy? 15m
The large-scale diffuse $\gamma-$ray flux observed by Fermi-LAT in the 1-100 GeV energy range is parameterized as a power law with spectral index $\Gamma$ that depends on the distance from the Galactic center.
This feature, if attributed to the diffuse emission produced by cosmic rays (CR) interactions with the interstellar gas, can be interpreted as the evidence of a progressive CR spectral hardening towards the Galactic center, challenging the standard cosmic rays diffusion paradigm.
We report on the implications of TeV Pulsar Wind Nebulae observed by the HESS Galactic Plane Survey in the 1-100 TeV energy range for the interpretation of Fermi-LAT data.
We show that the consistency among HGPS and Fermi-LAT (3FGL) catalogue requires that Galactic sources, observed by both experiments, have a spectral break at $\sim 0.1-1.0$ TeV and an harder emission spectrum in the GeV domain.
Such spectral shape is well compatible with the expected gamma-ray emission in young PWNe due to Inverse Compton scattering of high-energy electrons on background radiation fields.
We argue that a fraction of this population cannot be resolved by Fermi-LAT in the GeV domain providing a relevant contribution to the large-scale diffuse emission, viz. the $30\%$ of the total diffuse $\gamma$-ray emission in the inner Galaxy.
The inclusion of this additional component in fitting Fermi-LAT data strongly affects the spectral index for the truly diffuse emission, that can be increased by an amount $\Delta \Gamma=0.17$, weakening the evidence of a progressive hardening of the cosmic-ray proton spectrum in the inner Galaxy.Speaker: Vittoria Vecchiotti (GSSI) -
17:40
Supernova bounds on axion-like particles coupled with nucleons and electrons 15m
We investigate the potential of core-collapse supernovae (SNe) to constrain axion-like particles (ALPs) coupled to nucleons and electrons. ALPs coupled to nucleons can be efficiently produced in the SN core via nucleon-nucleon bremsstrahlung and, for a wide range of parameters, leave the SN unhindered producing a large ALP flux. For masses exceeding 1 MeV, these ALPs would decay into electron-positron pairs, generating a positron flux. In the case of Galactic SNe, the annihilation of the created positrons with the electrons present in the Galaxy would contribute to the 511 keV annihilation line. Using the SPI (SPectrometer on INTEGRAL) observation of this X-ray line, allows to exclude a wide range of the axion-electron coupling $10^{-19} < g_{ae} < 10^{-11}$ for $g_{ap} \sim 10^{-9}$. If ALPs decay in the extra-galactic medium, the electron-positron annihilations would yield a contribution to the cosmic X-ray background, allowing couplings down to $g_{ae}\sim 10^{-20}$ to be constrained.
Speaker: Giuseppe Lucente (Università di Bari & INFN Sez. Bari) -
17:45
A Numerical Study of Oscillations of Highly Magnetized Non-rotating Axisymmetric Neutron Stars 15m
Highly magnetized neutron stars with magnetic fields of $10^{15-16}$ G are promising candidates to be the observed soft gamma repeaters and X-ray pulsars. On the other hand, oscillations of perturbed neutron stars are closely related to the composition, structure, and equation of state of the star. Thus far, the numerical study of oscillations of magnetized neutron stars has not yet realized the observed order of field magnitude. Here, we present a breakthrough by using a multigrid-based general relativistic code,
Gmunu, to dynamically simulate the oscillations of highly magnetized non-rotating axisymmetric neutron stars with field strengths of $10^{15-17}$ G under non-linear perturbations. We extract the eigenfrequencies and eigenfunctions of the excited oscillation modes and preliminary results show that the eigenfrequencies decrease with the magnetic to binding energy ratio of the neutron star, implying a suppression of perturbative oscillations in a more magnetized neutron star.Speaker: Man Yin Leung (Department of Physics, The Chinese University of Hong Kong) -
17:45
Detecting and characterising pulsar halos with the Cherenkov Telescope Array 15m
The recently identified TeV source class of pulsar halos may be numerous and bright enough to constitute a large fraction of the sources that will be observed with the Cherenkov Telescope Array (CTA), especially in the context of the Galactic Plane Survey (GPS), one of the Key Science Projects of CTA. In this study, we examine the prospects offered by CTA for the detection and characterization of such objects. CTA will cover energies from 20 GeV to 300 TeV, in between those already probed by the Fermi-LAT and the High Altitude Water Cherenkov (HAWC) Observatory, and will also have a better angular resolution than both, allowing us to explore the radial profile of the halos. From simple models for individual pulsar halos and their population in the Milky Way, we examine under which conditions such sources can be identified in the GPS observations, possibly supplemented by additional dedicated exposure. In the framework of a full spatial-spectral likelihood analysis, we derive the sensitivity of CTA by considering both, general extended emission, and the specific physical pulsar halo model.
Speaker: Veronika Vodeb (UNG) -
17:45
Dissecting the inner Galaxy with gamma-ray pixel count statistics 15m
The nature of the GeV gamma-ray Galactic center excess (GCE) in the data of Fermi-LAT is still under investigation. Different techniques, such as template fitting and photon-count statistical methods, have been applied in the past few years in order to disentangle between a GCE coming from sub-threshold point sources or rather from diffuse emissions, such as the dark matter annihilation in the Galactic halo.
A major limit to all these studies is the modeling of the Galactic diffuse foreground, and the impact of residual mis-modeled emission on the results' robustness.
In Ref.[1], we combine for the first time adaptive template fitting and pixel count statistical methods in order to assess the role of sub-threshold point sources to the GCE, while minimizing the mis-modelling of diffuse emission components.
We reconstruct the flux distribution of point sources in the inner Galaxy well below the Fermi-LAT detection threshold, and measure their radial and longitudinal profiles. We find that point sources and diffuse emission from the Galactic bulge each contributes about 10% of the total emission therein, disclosing a sub-threshold point-source contribution to the GCE.[1] arXiv:2102.12497
Speaker: Silvia Manconi (TTK, RWTH Aachen) -
17:45
High-energy neutrinos from Supernovae: Prospects for Identification in Current and Future Neutrino Telescopes 15m
Neutrino emission from supernova has played a transformative role in the development of neutrino physics and our understanding of how the star works. Interaction of accelerated cosmic rays in the supernova ejecta and the circumstellar material will produce high-energy neutrinos. Current and future cubic kilometer neutrino telescopes can identify high-energy neutrinos from a supernova in the neighborhood of the Milky Way. Observation of high-energy neutrinos along with the MeV neutrinos from supernovae will provide unprecedented opportunities to understand unanswered questions in cosmic ray physics and neutrino physics. In this talk, we present the prospects for observation of high-energy neutrino bursts from in local galaxies by current and future neutrino telescopes and demonstrate how additions of new neutrino telescopes will extend the edge for identification of high-energy neutrinos from supernovae.
Speaker: Ali Kheirandish (Pennsylvania State University) -
17:45
Light Curves of BSM-induced Neutrino Echoes 15m
Astrophysical neutrinos present a unique opportunity to search for physics beyond Standard Model. Beyond Standard Model induced interactions of neutrinos during their propagation yield distinct signatures in their observables in neutrino detectors. Energy, flavor, arrival direction, and the arrival time of neutrinos can be modified when new physics is present. In particular, new physics scenarios will induce a time delay in the arrival time of neutrinos from astrophysical transients. The presence or absence of a delay in the arrival time of neutrinos compared to other cosmic messengers will provide a powerful probe of new physics in the neutrino sector. In this talk, we present the light curves for neutrino emission from transients for different new physics scenarios and discuss the expected temporal distribution for the arrival time of neutrino in each scenario. We highlight the power of time-domain multimessenger astrophysics and discuss the implications for current and future neutrino detectors.
Speaker: Ali Kheirandish (Pennsylvania State University) -
17:45
The MAGIC view of the very-high gamma-ray sky 15m
MAGIC is a system of two 17 meter Imaging Air Cherenkov Telescopes, located at the Observatorio Roque de los Muchachos at an altitude of 2200 meters on the Canary island of La Palma. It detects gamma rays in the very high energy regime between a few tens of GeV and tens of TeV. In this presentation, I will show the latest highlights achieved by the powerful low energy threshold of the instrument, like the measurement of the spectrum of the Geminga pulsar down to a few tens of GeV. I will also show the latest results on multiwavelength and multimessenger astronomy, in which MAGIC has played a leading role, putting special emphasis on the flaring blazar TXS 0506+056 coincident with high-energy neutrino IceCube-170922A and the very recent VHE gamma-ray measurement of the GRB 190114C.
Speaker: Ruben Lopez-Coto (INFN-Padova)
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Discussion Panel Neutrinos 1
Chair: Masaki Ishitsuka
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Energy-Dependent Neutrino Mixing Parameters at Oscillation Experiments 15m
One of the most important achievements in the field of particle physics is the discovery of neutrino oscillations. Despite already awarded Nobel Prize, neutrino oscillation experiments still have a lot to offer, primarily the discovery of CP violation in the lepton sector is anticipated. The parameters entering the expression for neutrino oscillation probabilities are neutrino mixing parameters and mass squared differences. In this talk, we argue that neutrino mixing parameters at production and detection do not necessarily need to be equivalent since such parameters are subject to renormalization group evolution and the process of neutrino production and detection occurs at different energies.In this talk we discuss this in the frame of an UV compete model; in particular we demonstrate that quantum effects can yield relevant observable effects at various neutrino experiments. As an example, we consider high-energy astrophysical neutrinos at IceCube and show that neutron decay production mechanism, that is considered to be strongly disfavored by present data, becomes viable if the significant renormalization group effects are present. We also scrutinize terrestrial experiments and show that the mismatch of neutrino parameters at production and detection can induce large effects at T2K and NOvA.
Speaker: Vedran Brdar (Fermilab and Northwestern University) -
17:25
Non-standard neutrino oscillations: perspective from unitarity triangles 15m
We formulate an alternative approach based on unitarity triangles to describe neutrino oscillations in presence of non-standard interactions (NSI). Using perturbation theory, we derive the expression for the oscillation probability in case of NSI and cast it in terms of the three independent parameters of the leptonic unitarity triangle (LUT). The form invariance of the probability expression (even in presence of new physics scenario as long as the mixing matrix is unitary) facilitates a neat geometric view of neutrino oscillations in terms of LUT. We examine the regime of validity of perturbative expansions in the NSI case and make comparisons with approximate expressions existing in literature. We uncover some interesting dependencies on NSI terms while studying the evolution of LUT parameters and the Jarlskog invariant. Interestingly, the geometric approach based on LUT allows us to express the oscillation probabilities for a given pair of neutrino flavours in terms of only three (and not four) degrees of freedom which are related to the geometric properties (sides and angles) of the triangle. Moreover, the LUT parameters are invariant under rephasing transformations and independent of the parameterization adopted.
Speaker: Poonam Mehta (Jawaharlal Nehru University) -
17:40
New unitarity constraints on the tau row 15m
Testing the unitarity of the PMNS matrix can give insights into the existence of additional neutrino generations which would render the 3x3 leptonic mixing matrix non-unitarity. Current oscillation data mostly constrains the electron and muon row of the mixing matrix whereas the tau row still allows for large unitarity violation. Here we will focus on new unitary constraints on the tau row coming from previously overlooked experimental data.
Speaker: Julia Gehrlein (Brookhaven National Laboratory) -
17:45
CPT violation in neutrino oscillations 15m
In this talk I consider CPT violating neutrino oscillations in its most general form, i.e. assuming different oscillation parameters for neutrinos and antineutrinos. In this scenario the measurement of oscillation parameters is much more difficult than in the standard case. I will discuss the implication on the recent CP measurements in T2K and NOvA, and also discuss how well current experiments can bound different neutrino and antineutrino parameters. Finally, I will discuss how well the upcoming DUNE experiment might improve the current bounds.
Speaker: Christoph Andreas Ternes (INFN, Sezione di Torino) -
17:45
DUNE long-baseline oscillation physics sensitivity 15m
The Deep Underground Neutrino Experiment (DUNE) is a next generation, long-baseline neutrino oscillation experiment which will utilize high-intensity $\nu_{\mu}$ and $\bar{\nu}_{\mu}$ with peak neutrino energies of ~2.5 GeV produced at Fermilab, over a 1285 km baseline, to carry out a detailed study of neutrino mixing. The neutrino beam has an initial design intensity of 1.2 MW, but has a planned upgrade to 2.4 MW. The unoscillated neutrino flux will be sampled with a near detector complex at Fermilab, and oscillated at the DUNE far detector at the Sanford Underground Research Facility, which will ultimately consist of four modules each containing a total liquid argon mass of 17 kt.
Here, the long-baseline neutrino oscillation sensitivity of DUNE is determined, using a full simulation, reconstruction, and event selection of the far detector and a full simulation and parameterized analysis of the near detector. Detailed uncertainties due to the flux prediction, neutrino interaction model, and detector effects are included. DUNE is able to resolve the neutrino mass ordering to a 5$\sigma$ precision, for all values of the CP-phase, after a 66 kiloton-megawatt-year exposure (kt-MW-yr). It has the potential to observe charge-parity violation in the neutrino sector to a precision of 3$\sigma$ (5$\sigma$) after an exposure of 197 (646) kt-MW-yrs, for 50% of all values of the CP-violating phase. DUNE's sensitivity to other oscillation parameters of interest have been explored.
Speaker: Callum Wilkinson (Lawrence Berkeley National Laboratory) -
17:45
Improving Hyper-Kamiokande sensitivity to CP violation with high precision near detector electron neutrino cross-section measurements 15m
The next generation long-baseline neutrino oscillation experiment, Hyper-Kamiokande, will consist of a 260 kt underground water Cherenkov detector, placed 295 km from the neutrino source at J-PARC. This is generated by a 1.3 MW proton beam striking a target. In addition, a suite of near detectors, both on and off-axis will be used. With this, Hyper-Kamiokande aims to perform precision measurements of the parameters governing neutrino oscillations, the observation of CP violation being one of the main aims of the experiment. To achieve these goals, Hyper-Kamiokande will require smaller systematic uncertainties than in any previous long-baseline experiment.
Many of these systematic uncertainties are related to neutrino-nucleus interactions, and can be constrained by a detector placed close to the beam production point. For this, the Hyper-Kamiokande long-baseline programme includes an Intermediate Water Cherenkov Detector, the IWCD. This is a 500 tonne water Cherenkov detector located 1 km from the beam production point. This detector is able to move within a vertical shaft and span a range of off-axis angles relative to the beam, from 1 to 4 degrees. The combination of large target mass, precise water Cherenkov reconstruction and off-axis angle flux dependence allows for high purity and high statistics electron neutrino and electron antineutrino samples. In this talk I will describe how this detector can be used to constrain the major systematic uncertainty affecting the measurement of CP violation at Hyper-Kamiokande: the electron neutrino and antineutrino interaction cross section.
Speaker: Charlie Naseby (Imperial College London) -
17:45
JUNO Oscillation Physics 15m
The Jiangmen Underground Neutrino Observatory is a 20 kton and 3\%/$\sqrt{E ({\rm MeV})}$ multi-purpose liquid scintillator detector located at a 700 m underground laboratory in the south of China (Jiangmen city, Guangdong province). The exceptional energy resolution and the massive fiducial volume of the JUNO detector offer great opportunities for addressing many essential topics in neutrino and astroparticle physics. JUNO's primary goals are to determine the neutrino mass ordering and precisely measure the related neutrino oscillation parameters. With six years of data taking with reactor anti-neutrinos, JUNO can determine the mass ordering at a 3-4$\sigma$ significance and the neutrino oscillation parameters $\sin^2\theta_{12}$, $\Delta m^2_{21}$, and $|\Delta m^2_{31}|$ to a precision of better than 0.6\%. In addition, the atmospheric neutrino and solar neutrino measurement at JUNO can also provide complementary and important information for neutrino oscillation physics.
This talk will focus on the oscillation physics of JUNO, which includes measurement and analysis of the reactor neutrinos, the atmospheric neutrinos, and the solar neutrinos. With the delicate energy response calibration and event reconstruction potential, JUNO will make a world-leading measurement on the neutrino oscillation parameters and neutrino mass ordering in the near future.
Speaker: Jinnan Zhang (Institute of High Energy Physics) -
17:45
Latest Results from the Daya Bay Reactor Neutrino Experiment 15m
Utilizing six powerful nuclear reactors as antineutrino sources and eight identically designed underground detectors for a near-far relative measurement, the Daya Bay Reactor Neutrino Experiment has achieved unprecedented precision in measuring the neutrino mixing angle θ13 and the neutrino mass squared difference |Δm231|. With the largest sample of reactor antineutrino interactions ever collected to date, Daya Bay has also performed many measurements of reactor antineutrinos, such as the determination of total reactor antineutrino flux and spectrum, the extraction of individual antineutrino flux and spectra of the two dominant isotopes (235U and 239Pu). On Dec. 12, 2020, the experiment stopped data taking. The decommissioning is going smoothly. In this talk, I will present the latest results from Daya Bay.
Speaker: Zeyuan Yu (Institute of High Energy Physics, CAS) -
17:45
Model-independent test of T violation in neutrino oscillations 15m
We propose a method to establish time reversal symmetry violation at future neutrino oscillation experiments in a largely model-independent way. We introduce a general parametrization of flavour transition probabilities which holds under weak assumptions and covers a large class of new-physics scenarios. This can be used to search for the presence of T-odd components in the transition probabilities by comparing data at different baselines but at the same neutrino energies. We show that this test can be performed already with experiments at three different baselines and might be feasible with experiments under preparation/consideration.
Speaker: Alejandro Segarra Tamarit (IFIC (CSIC-Univ Valencia)) -
17:45
NOvA's latest three-flavor neutrino oscillations results 15m
NOvA is a leading long-baseline neutrino experiment thanks to the powerful - nearly 700 kW - NuMI beam, which directs predominantly muon neutrinos from Fermilab, Illinois towards Ash River, in northern Minnesota. The experiment consists of two detectors placed 809 km apart, both about 14 mrad off-axis from the beam center. The detectors, one near and one far, were each formed from plastic extrusions filled with a liquid scintillator, making them functionally identical, which largely cancels key flux and cross-section systematic uncertainties. The three-flavor long-baseline search probes undetermined physics such as the neutrino mass hierarchy (ordering), CP violation in the lepton sector, and the octant of $\theta_{23}$ (the large mixing angle). The analysis to extract these parameters studies neutrino interactions in each detector to observe the disappearance of muon neutrinos and the appearance of electron neutrinos, due to oscillations. I will present the latest results from NOvA, based on the combined neutrino and antineutrino beam mode datasets, collected up to March 2020, and briefly discuss the future reach of the experiment.
Speaker: Ashley Back (Indiana University) -
17:45
Revealing the Majorana nature of neutrinos through a precision measurement of the CP phase 15m
We show that it is possible to reveal the nature of neutrino by measuring the Majorana phase at the DUNE experiment. The Majorana phase is activated in the neutrino oscillation framework ($\nu \rightarrow \nu$ and and $\bar{\nu}\rightarrow \bar{\nu}$) due to the introduction of a decoherence environment. Being that depending on the value of the Majorana phase and the intensity of decoherence, the measurement of the Dirac \textit{CP} violation phase $\delta_{\mathrm{CP}}$ can be highly spoiled. We will notice the latter by comparing the measurements of the CP phases that will take place in DUNE and T2HK. Finally, we will also asses the possibility of the measurement of the Majorana phase at DUNE.
Speaker: Alberto Gago Medina (Pontificia Universidad Católica del Perú) -
17:45
T2K Status and plans 15m
T2K is a long baseline experiment providing world-leading measurements of the parameters governing neutrino oscillation. T2K data enable the first 3 sigma exclusion for some intervals of the CP-violating phase \delta_{CP} and precision measurements of the atmospheric parameters \Delta_m^{2}{32}, sin^2(\theta{23}).
T2K exploits a beam of muon neutrinos and antineutrinos at the Japan Particle Accelerator Research Centre (JPARC) and it measures oscillations by comparing neutrino rates and spectra at a near detector complex, located at JPARC, and at the water-Cherenkov detector Super Kamiokande, located 295 Km away. The T2K beam will be upgraded with increased power in 2022 and an upgrade of the ND280 near detector, located 2.5 degrees off-axis, is being assembled to exploit the increased statistics. Moreover, the Super Kamiokande detector has been loaded with 0.02% of Gadolinium in 2020, enabling enhanced neutron tagging.
In preparation for the exploitation of such data, the T2K collaboration is working on an updated oscillation analysis to improve the control of systematic uncertainties A new beam tuning has been developed, based on an improved NA61/SHINE measurements on a copy of the T2K target and including a refined modelling of the beam line materials. New selections are being developed at ND280, with proton and photon tagging, and at Super Kamiokande, extending pion tagging to muon neutrino samples. After reviewing the latest measurements of oscillation parameters, the status of such new analysis developments and the plan to deploy the beam and ND280 upgrade will be presented.Speaker: Maria Antonova (IFIC (CSIC-Univ Valencia))
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Discussion Panel Neutrinos 2
Chairs: Ninetta Saviano & Sovan Chakraborty
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Primordial Black Hole Dark Matter evaporating on the Neutrino Floor 15m
Primordial black holes hypothetically generated in the first instants of life of the Universe are potential dark matter candidates. Focusing on Primordial Black Holes masses in the range $[5 \times10^{14} - 5 \times 10^{15}]$g, we point out that the neutrinos emitted by Primordial Black Holes evaporation can interact through the coherent elastic neutrino-nucleus scattering producing an observable signal in multi-ton Dark Matter direct detection experiments. We show that with the high exposures envisaged for the next-generation facilities, it will be possible to set bounds on the fraction of Dark Matter composed by Primordial Black Holes improving the existing neutrino limits obtained with Super-Kamiokande. We also quantify to what extent a signal originating from a small fraction of Dark Matter in the form of Primordial Black Holes would modify the so-called "neutrino floor", the well-known barrier towards detection of weakly interacting massive particles as the dominant Dark Matter component.
Speaker: Roberta Calabrese (Università degli studi di Napoli "Federico II") -
17:25
Neutrinos : from the r-process to the diffuse supernova neutrino background 15m
Neutrinos play an important role in astrophysical and cosmological environments.
In this talk I will discuss recent progress in neutrino flavor evolution in dense media, including core-collapse supernovae and binary neutron star mergers remnants. I will remind decoherence effects in vacuum and then discuss neutrino decoherence and other effects due to strong gravitational fields, nearby compact objects. I will highlight the implications of these aspects and/or of non-standard physics on observations, in particular in relation with the r-process and the GW170817 event, and with the diffuse supernova neutrino background, whose detection is expected soon.Speaker: Maria Cristina Volpe (APC and CNRS) -
17:40
Visible Decay of Astrophysical Neutrinos at IceCube 15m
Neutrino decay modifies neutrino propagation in a unique way; not only is there flavor changing as there is in neutrino oscillations, there is also energy transport from initial to final neutrinos. The most sensitive direct probe of neutrino decay is currently IceCube which can measure the energy and flavor of neutrinos traveling over extragalactic distances. For the first time we calculate the flavor transition probability for the cases of visible and invisible neutrino decay, including the effects of the expansion of the universe, and consider the implications for IceCube. As an example, we demonstrate how neutrino decay addresses a tension in the IceCube data.
Speaker: Peter Denton (Brookhaven National Laboratory) -
17:45
Astroparticle physics in DUNE with the X-Arapuca detectors 15m
DUNE is a long-baseline accelerator experiment currently in construction at Fermilab and SURF (South Dakota).
The science objectives of DUNE include a comprehensive investigation of long-baseline neutrino oscillations and, in particular, the study of CP violation in the neutrino sector and the identification of the neutrino mass hierarchy, along with high-sensitivity rare event searches like the observation of supernova neutrino bursts and the search for proton decay.
The Far Detector consists of four Liquid Argon TPCs located deep underground,
which represents a unique observatory for astroparticle physics. The DUNE physics reach in such a field is remarkably enhanced by the DUNE Photon Detection System (PDS) that is based on a novel light trapping technology (X-Arapuca).
In this talk, we will present the latest results obtained by the PDS Consortium in terms of light efficiency and cryo-reliability of the X-Arapuca, together with the most important technological achievements to cover the large surface of the DUNE anodes. We will also discuss the role of the PDS for the study of supernova neutrino bursts and the search for proton decay. Finally, we will present the latest development of this technique, based on a new class of photon downshifting polymeric material and the impact on the physics reach of DUNE.Speaker: Claudia Brizzolari -
17:45
Fast Flavor Ocillations of Supernova neutrinos in three flavors 15m
Neutrinos emitted from a core-collapse supernova (SN) may undergo fast flavor
conversions almost immediately above the core, resulting in drastic
consequences for the supernova explosion mechanism and nucleosynthesis.
These fast flavor oscillation dynamics are independent of the neutrino mass,
growing at the scale of the large neutrino-neutrino interaction strength (10^5 km^ −1
) of the dense core which is extremely fast, in comparison to the usual ‘slow’
collective modes driven by much smaller vacuum oscillation frequencies (10^0
km^−1 ). The necessary condition for the existence of these fast instabilities is the
presence of a zero-crossing in the angular distribution of the neutrino lepton
number. The previous literature on fast conversions have focussed on an
effective two-flavor analysis, where the zero crossing in electron lepton number
(ELN) was crucial since the assumption of similar number density of the the
heavy lepton neutrinos lead to similar angular spectra. However, motivated
from the recent supernova simulations with muon production in the accretion
phase, we perform the first non-linear simulations of fast conversions in the
presence of all the three neutrino flavors. Our results show the significance of
muon and tau lepton number angular distributions, along with the traditional
electron lepton number ones and strengthen the need to further investigate the
occurrence of fast conversions in supernova simulation data, including the
degeneracy breaking of mu and tau neutrinos.Speaker: Madhurima Chakraborty (IIT Guwahati) -
17:45
JUNO Non-oscillation Physics 15m
The JUNO observatory, a 20 kt liquid scintillator detector to be completed in 2022 in China, belongs to the next-generation of neutrino detectors, which share the common features of having a multi-ton scale and an energy resolution at unprecedented levels.
Beside the ambitious goal of neutrino mass ordering determination, the JUNO Collaboration plans also to perform a wide series of other measurements in the neutrino and astroparticle fields, rare processes and searches for new physics. The detector characteristics will allow the detection of neutrinos from many sources, like supernovae, the Sun, atmospheric and geoneutrinos. Other potential studies accessible to JUNO include the search for exotic processes, such as nucleon decays, Dark Matter and magnetic monopoles interactions, light sterile neutrinos production.
This talk will review the potential of JUNO about non-oscillation physics, highlighting the unique contributions that the experiment will give to the various fields in the forthcoming years.Speaker: Giulio Settanta (Forschungszentrum Jülich GmbH, Nuclear Physics Institute IKP-2, Jülich, Germany) -
17:45
KM3NeT: Status and perspectives for neutrino astronomy from the MeV to the PeV 15m
KM3NeT is a multi-purpose neutrino observatory currently being deployed at the bottom of the Mediterranean Sea. It consists of two detectors: ORCA and ARCA (for Oscillation and Astroparticle Research with Cosmics in the Abyss). ARCA will instrument 1 Gton of seawater, with the primary goal of detecting cosmic neutrinos with energies between several tens of GeV and PeV. Due to its position in the Northern Hemisphere, ARCA will provide an optimal view of the Southern sky including the Galactic Center. This month, a major step has be taken in the construction of ARCA, bringing the total number of detection lines from one to six. ORCA, also currently running in a 6-line configuration, is a smaller (~ few Mtons) and denser array, optimized for the detection of atmospheric neutrinos in the 1 - 100 GeV. It can also study low-energy neutrino astronomy, such as MeV-scale core-collapse supernova.
Speaker: Silvia Celli (Sapienza Università di Roma) -
17:45
Modeling neutrino emission for different gamma-ray burst production scenarios 15m
Gamma ray-bursts (GRBs) are among the least understood and most powerful transients occurring in our Universe. Different dissipation and emission processes have been proposed over the years to interpret their origin. However, we still lack an exhaustive theoretical explanation due to the failure of existing models in addressing all observations in the spectral and temporal domains. GRBs are also candidate sources of high energy neutrinos detected by IceCube Neutrino Observatory. I will discuss the neutrino emission in different dissipation scenarios, and show that the neutrino prediction strongly depends on the adopted jet model, highlighting the importance of neutrinos in pinpointing the GRB emission mechanism in the case of successful neutrino detection.
Based on Pitik, Tamborra, and Petropoulu, arXiv:2102.02223Speaker: Tetyana Pitik (Niels Bohr International Academy) -
17:45
Seach for supernova relic neutrinos at KamLAND 15m
We report a search for electron antineutrinos at KamLAND with an energy range of 8.3--30.8 MeV via the inverse beta decay.
In 4528 days of KamLAND data, we found 18 event candidates and no significant excess over estimated backgrounds.
From data interpretation, with the assumption of some supernova relic neutrino spectrum predictions, we give upper flux limits of $60$--$110\,{\mathrm{cm}^{-2}\mathrm{s}^{-1}}$ ($90\%$ CL) in the analysis range and present a model-independent flux.
These upper limits are the most stringent for 8.3--12 MeV region to date.
We also improve on the upper probability limit of $^8$B solar neutrinos converting into antineutrinos via the Resonant Spin Flavor Precession with the neutrino magnetic moment.
Besides, we could set limits on the annihilation cross section for light dark matter pairs to neutrino pairs.Speaker: Shuhei Obara (Tohoku University) -
17:45
Search for neutrino counterparts of LIGO/Virgo gravitational-wave events 15m
The LIGO/Virgo collaborations have reported the results of their searches for gravitational-waves from the first half of their third observing run. 39 events were added to the first Gravitational-Wave Transient Catalog (GWTC-1), reaching the total number of 50. Thus, an additional search for counterparts is necessary. The data from Baksan Underground Scintillation Telescope (BUST) are used to search for neutrino counterparts. The BUST detections of muons from the lower hemisphere in the zenith angles >100° are used. The angular uncertainty of muon neutrinos and antineutrinos from the lower hemisphere is ~5°. The energy threshold is 1 GeV. If no counterparts found the integral fluxes of muon neutrinos and antineutrinos are calculated. This work presents the description of data processing and the limits on integral fluxes from the gravitational-wave localization regions.
Speaker: Islam Unatlokov (BNO INR RAS) -
17:45
Simulation of Nuclear Recoils due to Supernova Neutrino-induced Neutrons in Liquid Xenon Detectors 15m
Detectable number of nuclear recoil (NR) events can occur from neutrinos from supernova (SN) bursts through the coherent elastic neutrino-nucleus scattering (CE$\nu$NS) process in large scale liquid xenon detectors designed for direct dark matter search depending on the SN mass and distance. In this presentation, we show that in addition to the direct NR events due to CE$\nu$NS process, the SN neutrinos can be detected via the nuclear recoils due to the elastic scattering of the neutrons produced due to the inelastic interactions of the neutrino with the xenon nuclei. We find that the contribution of the supernova neutrino-induced neutrons ($\nu$I$n$) can significantly modify the total xenon NR spectrum, at large recoil energies, from the spectrum expected from CE$\nu$NS contribution alone. Moreover, for recoil energies $>20$ keV, the dominant contribution is obtained from the ($\nu$I$n$) events. Using the nuclear spectra of both the CE$\nu$NS and the $\nu$I$n$ events, we numerically calculate the observable S1 and S2 signals for a typical liquid xenon based detector accounting for the multiple scattering effects for the $\nu$I$n$ and find that at sufficiently large signals events, S1$>$50 photo-electrons (PE) and S2$>$2300 PE, are dominantly contributed by $\nu$I$n$ scatterings. We note that since $\nu$I$n$ contribution to the recoil spectrum arises due to the charged current interaction of the SN $\nu_e$s with the target nuclei while the neutral current interactions, responsible for CE$\nu$NS events, comes from of all the six species of neutrinos, the capability of detecting these individual recoil events, especially in the S2 channel, in future large scale liquid xenon detectors may offer the possibility of extraction of information regarding the distribution of the SN explosion energy into different flavours of neutrinos.
Speaker: Sayan Ghosh (Saha Institute of Nuclear Physics) -
17:45
SNEWS2.0: The Multi-Messenger Supernova Early Warning System 15m
Core collapse supernovae (CCSN) are among the most precious multi-messenger events of the extreme Universe. These events are extremely rare, and it will be crucial to gather all the physics possible from the data of the next event. The SNEWS public alert system was designed to provide an early alert to astronomers and other observers about the observation of neutrinos from a Galactic CCSN, which are produced minutes to hours before the electromagnetic radiation. SNEWS has been operating for more than two decades, searching for a coincident signal between neutrino experiments from all around the world. In the current era of multi-messenger astrophysics, there are new opportunities for SNEWS to optimize the science reach from the next Galactic supernova beyond the simple early alert. In this talk, the upgrades and new capabilities of SNEWS2.0 will be discussed.
Speaker: Marta Colomer Molla (APC/IFIC)
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18:00
Discussion Panel Underground Laboratories 1
Chairs: Aldo Ianni & Jeter Hall
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17:10
Callio Lab – the deep underground research centre in Finland, Europe 15m
Located just below the Polar circle, Callio Lab is one of the northernmost underground laboratories in Europe [1,2]. The underground research centre has developed from underground physics (formerly known as the Centre for Underground Physics in Pyhäsalmi, CUPP [3]). Over the years, its strategy has been shifted to a multi-and transdisciplinary research centre, now known as Callio Lab.
The Callio Lab is physically located at the 1.44 km deep Pyhäsalmi mine, Pyhäjärvi, Finland. The mine has produced copper, zinc and pyrite since its opening in 1962. The deposit is geologically located within a 1.9 bn-year-old seafloor and belongs to the class of volcanic massive sulphide (VMS) deposits [4]. Seismically the bedrock is stable and tremors are mainly induced by the mining activities. The mine has a flat overburden, and access to the mine is through an 11 km incline or the 1.4 km deep elevator shaft. The travel times are 30 minutes and 2.5 minutes, respectively [5].
The development of underground research facilities in the Pyhäsalmi mine started in the late 1990s at the margin of the then known ore resources. However, with the discovery of a new deposit below the old one, the life span of the underground mining was extended year by year. However, it is expected that mining will cease at the later part of 2021. The eventual end of underground extraction will give more room and possibilities for science, research and business. The latter is governed by the Callio – Mine for business [6], governed by the local town. The scientific activities of Callio Lab are coordinated by the University of Oulu, Finland.
Throughout the years the various scientific activities and research initiatives have been started at the Callio Lab. The characterisation of underground halls (i.e., Labs in the facility) has included the on-site natural background radiation measurements (gamma, neutron, radon) and sample analysis of the building materials used and samples of the surrounding bedrock [7–12]. The muon background measurements were done in 2005 [13]. The rock overburden at a depth of 1390 has been measured to be 4000 m.w.e., and at Lab 2, located at a depth of 1436m, it is estimated around 4100 m.w.e [5].
The scientific activities at utilising the Callio lab research infrastructure range from mining and mining-related training to geothermal concept and technology testing, underground food production, working environment research, and particle physics. The low-background facility, using the low background HPGe detector from Baltic Scientific Instruments, is located at Lab 5 at a depth of 1410 m. [14]. The facility provides sample analysis services for the EUL project laboratories [15], but other scientific institutions benefit from the facility too.
Callio Lab is part of the DULIA network, a founding member of the European Underground Laboratories association [15], a candidate as a thematic core service for the European Plate Observation System, EPOS [16], member of Nordic and Finnish EPOS research infrastructures, and is a strategic research infrastructure of the University of Oulu. EPOS is on the European and Finnish research infrastructure roadmaps.This work has been supported by grants by the Interreg Baltic Sea programme and Nordforsk.
References
1. Puputti J, Joutsenvaara J, Kotavaara O, Niinikoski E-R. 2021 From Earth and beyond - Callio Lab underground centre for Science and R\&D. In EGU General Assembly Conference Abstracts, pp. EGU21-14229.
2. 2021 Callio Lab. See https://calliolab.com/facilities-2/facilities/ (accessed on 20 April 2021).
3. Enqvist T et al. 2005 Research options in the pyhäsalmi underground facility. Nucl. Phys. B - Proc. Suppl. 143, 561. (doi:10.1016/j.nuclphysbps.2005.01.226)
4. Mäki T, Kousa J, Luukas J. 2015 The Vihanti-Pyhäsalmi VMS Belt. In Mineral Deposits of Finland, pp. 507–530. Elsevier Inc. (doi:10.1016/B978-0-12-410438-9.00020-0)
5. Joutsenvaara J (Jari). 2016 Deeper understanding at Lab 2:the new experimental hall at Callio Lab underground centre for science and R & D in the Pyhäsalmi Mine, Finland. University of Oulu. See http://urn.fi/URN:NBN:fi:oulu-201606042350.
6. 2021 Callio - Mine for Business. See https://callio.info.
7. Debicki Z, Jedrzejczak K, Kasztelan M, Marszal W, Orzechowski J, Szabelski J, Tokarski P. 2019 Measurements of thermal neutron flux in underground laboratories, a standard proposal for the BSUIN project. In The multi-messenger astronomy: gamma-ray bursts, search for electromagnetic counterparts to neutrino events and gravitational waves, pp. 48–54.
8. Jedrzejczak K, Kasztelan M, Szabelski J, Tokarski P, Orzechowski J, Marszał W, Przybylak M. 2020 Characteristics of natural neutron radiation background performed within the BSUIN project. In EGU General Assembly Conference Abstracts, p. 3353.
9. Polaczek-Grelik K et al. 2020 Natural background radiation at Lab 2 of Callio Lab, Pyhäsalmi mine in Finland. Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip. 969, 164015. (doi:10.1016/j.nima.2020.164015)
10. Gostilo V, Sokolov A, Pohuliai S, Joutsenvaara J. 2020 Characterisation of the natural gamma-ray background in the underground Callio Lab facility. Appl. Radiat. Isot. 156, 108987. (doi:10.1016/j.apradiso.2019.108987)
11. Abdurashitov J. N. GVNMVLSAAYVEPJKT. 2006 Measurement of Neutron Background at the Pyhasalmi mine for CUPP Project, Finland. arXiv:nucl-ex
12. Pohuliai S, Sokolov A, Gostilo V, Joutsenvaara J, Puputti J. 2020 Measurements of gamma-ray background radiation in Pyhäsalmi mine. Appl. Radiat. Isot. 161. (doi:10.1016/j.apradiso.2020.109166)
13. Enqvist T et al. 2005 Measurements of muon flux in the Pyhäsalmi underground laboratory. Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip. 554, 286–290. (doi:10.1016/j.nima.2005.08.065)
14. Pohuliai S, Sokolov A, Gostilo V, Joutsenvaara J, Puputti J. 2020 Measurements of gamma-ray background radiation in Pyhäsalmi mine. Appl. Radiat. Isot. 161, 109166. (doi:10.1016/j.apradiso.2020.109166)
15. Mischo H, Fuławka K, Joutsenvaara J. 2021 European Underground Laboratories Association EUL-An International Partner for Underground Research Opportunities. In EGU General Assembly Conference Abstracts, pp. EGU21--7730.
16. Elger K, Lauterjung J, Ulbricht D, Cocco M, Atakan K, Bailo D, Glaves H, Jeffrey K. 2016 Implementation of the European Plate Observing System (EPOS) Infrastructure.Speaker: Jari Joutsenvaara (Kerttu Saalasti Institute, University of Oulu) -
17:10
Status and prospect of China Jinping Underground Laboratory 15m
China Jinping underground laboratory (CJPL) is located in the Jinping Mountain, Sichuan Province, southwest China, with a rock overburden of about 2400m. The laboratory is operated by Tsinghua University and Yalong River Hydropower Development Company, LTD. The scientific project at CJPL is mainly focused on dark matter detection, nuclear astrophysics and low background screening techniques. Based on CJPL extension project (CJPL-II), the Deep Underground and ultra-low Radiation Background Facility for frontier physics experiments (DURF) will start construction this September. This talk will give an overview of CJPL status and DURF project, as well as main experiments and scientific activities carried out at CJPL.
Speaker: Hao Ma (Tsinghua University) -
17:10
The New Underground Facility (Yemilab) in Korea 15m
A new underground facility called Yemilab with a depth of 1,000 m will be constructed for studies on neutrinos and dark matter search. The new underground facility is located within the site of an iron mine in Jeongseon-gun, Gangwon-do, South Korea. Since the mine has a vertical shaft with a diameter of 6 m and a length of 600 m, the facility uses this shaft. The construction of the new underground facility consists of a cage for passengers (man-cage) to enter the underground, excavation of tunnels with a total area of 10,000 m$^2$ including a dedicated area of 2,600 m$^2$ for experiments, and construction of electrical and mechanical facilities for operation. The construction is carried out in two phases. In the first phase, man-cage manufacture/installation and most of the tunnel excavation were carried out. In the second stage, excavation of a large cylindrical pit with dimensions of 20 m (D) x 20 m (H) is being carried out together with the installation of a 2 MW power supply and construction of facilities for ventilation, drainage, and fire prevention. The first phase construction started in 2018 and was completed in August 2020. The second phase construction started in May 2021 and is going to be completed in May 2022. The Yemilab will be introduced in this presentation.
Speaker: Kang Soon Park (Institute for Basic Science (IBS)) -
17:25
Low radioactivity and Multi- disciplinarily Underground Laboratory of Modane (LSM) 15m
The Modane Underground Laboratory (LSM) is located 1700 m (4800 m.w.e) below Fréjus peak (Alpes chain) mountain in the middle of the Fréjus tunnel between France/Italy. The LSM is a multi-disciplinary platform for the experiments requiring low radioactivity environment. Several experiments in Particle and Astroparticle Physics, low-level of High Purity of Germanium gamma ray spectrometry, biology and home land security hosted in the LSM. It’s equipped by Anti-Radon facility where all of the detectors are under Radon depleted Air. We will present the LSM structure and briefly reviewed of all experiments are installed in.
Speaker: Ali Dastgheibi Fard (CNRS/LPSC_LSM) -
17:45
Deep Science at Boulby Underground Laboratory 15m
An update of facilities and science in the UK's deep underground science facility. For more than three decades astro-particle physicists have been operating experiments to search for Dark Matter 1100m below ground in a purpose-built low-background facility at Boulby mine in the North East of England. Dark Matter studies continue at Boulby. The facility currently supports various smaller Dark Matter R&D studies and operates the BUGS facility - a growing suite of high sensitivity Germanium detectors and surface alpha measurement systems needed to undertake ever-more sensitive material screening measurements for rare-event studies. In the meantime the range of science projects exploiting the special properties of deep underground environment at Boulby has grown, with projects current and/or planned in the areas of astroparticle and low background science, Earth and environmental science, biology/astrobiology and planetary exploration technology development. For the future Boulby is planning to expand to host future major rare-event and wider multidisciplinary science studies. This talk will give an overview of the Boulby Underground Laboratory, the science currently supported and plans for science at Boulby in the future.
Speaker: Sean Paling (STFC Boulby Underground Laboratory) -
17:45
LABChico: a shallow underground laboratory in Mexico 15m
LABChico will be an underground laboratory in Mineral del Chico, Comarca Minera, Hidalgo UNESCO Global Geopark, in Mexico inside a decommissioned mine with an approximate rock overburden of 100 meters. This laboratory currently under development and with construction planned by the end of 2021, will be primarily focusing on research in low background gamma assay for neutrino and dark matter experiments, detector prototypes, and applications related to environmental radioactivity by measuring the presence of radionuclides in food, soil, and water. The facility will initially host two HPGe detectors for gamma assays and plastic scintillator counters for muon flux measurements used for educational purposes. LABChico is supported by the National Autonomous University of Mexico (UNAM), the government of Hidalgo and the Comarca Minera, Hidalgo UNESCO Global Geopark in Mexico, and the Global Challenges Research Fund in the UK. In this talk, I will present the current status of the facility, measurements of gamma backgrounds at the location of the laboratory, and the results of the gamma and alpha screening program.
Speaker: Eric Vazquez-Jauregui (Instituto de Física, UNAM) -
17:45
The ANDES Deep Underground initiative and underground mine sites in Argentina 15m
ANDES is an international effort to build a world class deep underground laboratory at the border between Argentina and Chile in the planned Agua Negra tunnel. With 1750 m of overburden, horizontal access, and 70 000 m3 of volume, it should offer an attractive option in the southern hemisphere to the underground science community. As the construction of the tunnel and laboratory is planned to take 10 years, efforts are also currently focused on providing to the regional community alternative shallow sites to start developing prototype for future underground science detectors.
I will discuss the status of ANDES and the prospects for 2 mine sites in Argentina, the Sierra Grande mine which was used in the 1990s for a dark matter experiment, and the mina Casposo, in the vicinity of the location planned for ANDES.Speaker: Xavier Bertou (CNEA/CONICET) -
17:45
The Sanford Underground Research Facility 15m
The Sanford Underground Research Facility (SURF) has been operating since 2007 supporting underground research in rare-process physics, as well as offering research opportunities in other disciplines. SURF laboratory facilities include a Surface Campus as well as campuses at the 4850-foot level (1500 m, 4300 m.w.e.) that host a range of significant physics experiments, including the LUX-ZEPLIN (LZ) dark matter experiment and the MAJORANA DEMONSTRATOR neutrinoless double-beta decay experiment. The CASPAR nuclear astrophysics accelerator recently completed the first phase of operation. Furthermore, the BHUC laboratory dedicated to critical material assays for current and future experiments has been operating since Fall 2015. Construction is underway for the Long-Baseline Neutrino Facility (LBNF) that will host the international Deep Underground Neutrino Experiment (DUNE). SURF is a dedicated research facility with significant expansion capability, and applications from new experiments are welcome.
Speaker: Jaret Heise (Sanford Underground Research Facility) -
17:45
The Sar-Grav Laboratory 15m
Located in Sardinia close to Lula, the region of the Sos Enattos mine is understudies to host the third generation of gravitational wave interferometer: Einstein Telescope (ET). The Sar-Grav laboratory, a seed of ET, will host underground experiments, cryogenic payloads, low frequency and cryogenic sensor development that need low seismic and anthropogenic noise. Indeed, the Sos Enattos mine already hosts seismometer and magnetometer nets, located both on the surface and underground, that prove the quietness of the site. On the surface area, the Sar-Grav laboratory is characterized by a hangar of 900 square meters equipped with rooms for the experiments, an optical laboratory, and a control room. An area of 250 square meters and small experimental areas are planned to be located underground where stations at different depths already host the sensors net.
Speaker: Davide Rozza (INFN-LNS & University of Sassari)
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Poster session 1
Join the Gather.Town platform at:
https://gather.town/invite?token=2H8MJOdA-
18:00
Analysis techniques for the search of 128-Te 0vbb decay with the CUORE TeO2 cryogenic crystals 15m
CUORE is a ton-scale experiment comprised of 988 TeO2 cryogenic crystals, located at the underground Laboratori Nazionali del Gran Sasso of INFN (Italy). The CUORE detectors are operated as pure calorimeters at a base temperature of ~10 mK, that is reached and maintained thanks to a custom built cryogen-free dilution cryostat designed with the aim of minimizing the vibrational noise and the environmental radioactivity.
In addition to the search for neutrinoless double beta decay of 130-Te, which represents the main physics goal of CUORE, its ultra-low background and large mass make it suitable for the search of other rare processes. One of these is the neutrinoless double beta decay of 128-Te, the second tellurium isotope with the highest natural isotopic abundance (31.75%). The study of this transition is complicated by the high background present in the energy region where the decay peak is expected, namely at (866.7 +/- 0.7) keV. The dominant contribution to this background is due to the 130-Te two-neutrino double beta decay events.
CUORE represents the first experiment able to operate a ton-scale mass of cryogenic TeO2 bolometers in stable conditions, and this allows it to access a factor >10 higher sensitivity to the neutrinoless double beta decay of 128-Te with respect to past direct experiments.Speaker: Valentina Dompè -
18:15
New results and perspectives on 130Te double beta decay to the first 0+ excited state from CUORE 15m
The CUORE experiment is a closely packed array of 988 cryogenic calorimeters aimed at investigating lepton number violation via neutrino-less double beta decay (0νββ) in 130Te. We present the latest results on searches for the double beta decay (DBD) of 130Te to the first 0+ excited state of 130Xe in the 0νββ and Standard Model channels and discuss future perspectives. The de-excitation gamma rays emitted by the excited Xe nucleus in the final state yield a unique signature, which can be searched for with low background by studying coincident events in two or more bolometers. With a 372.5 kg×yr TeO2 exposure the median limit setting sensitivities at 90\% Credible Interval (C.I.) were estimated as 5.6 × 10^24 yr for the 0νββ decay and 2.1 × 10^24 yr for the 2νββ decay. No significant evidence for either of the decay modes was observed and a Bayesian lower bound at 90% C.I. on the decay half lives is obtained as: (T1/2)0ν0+ > 5.9 × 10^24 yr for the 0νββ mode and (T1/2)2ν0+ > 1.3 × 10^24 yr for the 2νββ mode. These represent the most stringent limits on the DBD of 130Te to excited states and improve by a factor ∼5 the previous results on this process.
Speaker: Guido Fantini (Università di Roma La Sapienza) -
18:30
Searching for New Physics in 2$\nu$DBD Decay with CUPID 15m
The development of cryogenic calorimeters to search for neutrinoless double-beta decay (0$\nu$DBD) has given in the last years increasingly promising results.
To achieve a nearly background-free condition, scintillating crystals for 0$\nu$DBD have been developed. Thanks to the light-assisted particle discrimination, this technology demonstrated the complete rejection of the dominant alpha background. In addition, the possibility of achieving ton-scale exposures, maintaining an excellent energy resolution, lays the foundations for the CUPID project.
CUPID is a next-generation experiment aiming to exploit $^{100}$Mo enriched scintillating Li$_2$MoO$_4$ crystals, operating as cryogenic calorimeters, to investigate the entire inverted hierarchy region for neutrino messes. Thanks to the high Q$_{\beta\beta}$ of $^{100}$Mo and the $\alpha$-discrimination, the CUPID goal is to achieve a background level in the region of interest of 10$^{-4}$ counts/(keV kg yr).
Although the 0$\nu$DBD is the main objective of CUPID, other processes are open to experimental investigation, particularly those inducing a distortion of the 2$\nu$DBD spectral shape. Given the relatively fast half-life of $^{100}$Mo 2$\nu$DBD, we expect to reach unprecedented sensitivities in the search for 2$\nu$DBD bSM induced distortions.
In this poster a general overview of the CUPID experiment will be given as well as the first sensitivity estimation on others bSM processes.Speaker: Emanuela Celi (Gran Sasso Science Institute) -
18:45
Prospects of search for new physics in the Double Beta Decay with KamLAND-Zen 800 15m
Two-neutrino double beta decay (2$\nu\beta\beta$) is a rare radioactive decay that is a weak process of second-order. It has been observed in neutrino-less double beta decay (0$\nu\beta\beta$) search experiments to verify the Majorana nature of neutrino. Precise observation of 2$\nu\beta\beta$ is important to reduce the theoretical uncertainty in the calculation of nuclear matrix elements required to obtain the effective Majorana mass from a lifetime of 0$\nu\beta\beta$. Also, 2$\nu\beta\beta$ itself is interesting because new physics could be hiding in the energy spectrum, for examples, Majoron emission mode 0$\nu\beta\beta$ and 2$\nu\beta\beta$ with neutrino-self-interaction.
KamLAND-Zen 800 is an experiment to search 0$\nu\beta\beta$ of $^{136}$Xe with ultra-pure large liquid scintillator detector, KamLAND. KamLAND-Zen 800 has been observing since 2019 with 750 kg of Xenon gas 91% enriched in $^{136}$Xe. We can analyze 2$\nu\beta\beta$ with high statistics.
I present the prospects of precisely measurement of 2$\nu\beta\beta$ half life and search for new physics in 2$\nu\beta\beta$ with KamLAND-Zen 800 in this presentation.Speaker: Yuto Kamei (Research Center for Neutrino Science, Tohoku university) -
19:15
A novel method to fabricate electronic substrates of CDEX-100 by applying surface modification of low-background polymers 15m
The detection of rare events requires transmitting the extremely weak signal, in which electronic substrates with low background levels and strong binding forces are extremely important. Polytetrafluoroethylene (PTFE) and its homologue poly (perfluoroethylene, FEP) are excellent low background and high dielectric layers in electronic substrates widely applicated in rare event detection experiments. For JFET to transmit and amplify weak signals, they are usually positioned very close to the detector. Therefore, electronic substrates are required to be screened out to have low background levels, good adhesion and low-temperature resistance to meet the requirements of rare event detection experiments.
Surface modification of dielectric layers with PTFE and FEP is carried out by ion implantation, to solve the problem of difficult metallization between polymer and metal layers of electronic substrates. The Stopping and Range of Ions in Matter (SRIM) simulation is used to analyze the implantation depth and ion distribution of the surface. A transition layer and electrolytic copper are deposited on the polymer by the filtered cathode vacuum arc and electrochemical methods, respectively. The morphology, active groups and valence bonds are evaluated to determine the microstructure characteristics. Correspondingly, the mainly adhesion mechanism between copper and the dielectric is explained by mechanical anchoring physical action, chemical bonding and intermolecular forces. Furthermore, γ-ray background of electronic substrates prepared by us is relatively lower than common commercial devices.
We offer a new method to fabricate the direct surface metallization of perfluorinated polymers. The surface modification of polymer is to obtain electronic substrates with low background levels and low-temperature resistance, which has good electrical performance, and is also applied to China Dark matter EXperiment tests.Speaker: Shaojun Zhang (China Dark matter EXperiment (CDEX) member, Key Laboratory of Beam Technology of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, China) -
19:15
Annual Modulations of the Angular Recoil-Flux/Energy Distributions of WIMP-Scattered Target Nuclei Observed at an Underground Laboratory 15m
While most direct Dark Matter detection experiments measure only the recoil energies of (elastic) WIMP-nucleus scattering events deposited in underground laboratory detectors, "directional" DM detection experiments aim to provide 3-dimensional information (recoil tracks and/or head-tail senses) of WIMP-scattered target nuclei, as a promising experimental strategy for discriminating WIMP signals from backgrounds. In this talk, I will first introduce briefly our double-Monte Carlo scattering-by-scattering simulation package for 3-dimensional elastic WIMP-nucleus scattering. Then I will demonstrate and compare the "annual modulations" of the angular distributions of the recoil direction (flux)/energy of target nuclei observed in different underground laboratories. The impacts of the cross section (nuclear form factor) suppression as well as some common misunderstandings in literature will particularly be discussed in detail.
Speaker: Chung-Lin Shan (Preparatory Office of the Supporting Center for Taiwan Independent Researchers)CLShan-taup2021-dm-ddd-NR_ang-ANDES.pdf CLShan-taup2021-dm-ddd-NR_ang-Boulby.pdf CLShan-taup2021-dm-ddd-NR_ang-Kamioka.pdf CLShan-taup2021-dm-ddd-NR_ang-LNGS.pdf CLShan-taup2021-dm-ddd-NR_ang-LSC.pdf CLShan-taup2021-dm-ddd-NR_ang-LSM.pdf CLShan-taup2021-dm-ddd-NR_ang-SNOLAB.pdf CLShan-taup2021-dm-ddd-NR_ang-SUPL.pdf -
19:15
BSM sources of CP violation at future long baseline experiments 15m
Neutrino Oscillations are one of the most important discoveries of the last thirty years. Many experiments looking at neutrinos from different sources were able to measure with a good precision almost all the oscillation parameters. However, considering parameters uncertainties, there is still room for the possibility of the presence of Beyond Standard Model (BSM) effects. Some of the most studied New Physics scenarios in the Neutrino Oscillations framework are sterile neutrinos, Non Standard Interactions and Non Unitarity models.
We studied the potentialities of future long baseline experiments like DUNE to look for BSM sources of CP violation measuring only the CP asymmetries in different oscillation channels. The relatively easiness of the measurement of such quantities, the large amount of expected data and the great performances of LBL experiments could in principle provide a simple but powerful method to search for new physics effects.Speaker: Alessio Giarnetti (Roma Tre University and INFN) -
19:15
Building low background kton-scale liquid argon time projection chambers for physics discovery 15m
With radiopurity controls and small design modifications a kton-scale liquid argon time projection chamber similar to DUNE could be used for enhanced low energy physics searches. This includes improved sensitivity to supernova and solar neutrinos, and even weakly interacting massive particle dark matter. This talk will present initial simulation studies to optimize the design and evaluate physics sensitivities. It will also discuss the tools being developed to support a large-scale radiopurity assay campaign necessary to construct such a detector.
Speaker: Christopher Jackson (Pacific Northwest National Laboratory) -
19:15
Characterization of the DUNE photodetectors and study of the event burst phenomenon 15m
The Deep Underground Neutrino Experiment (DUNE) is an upcoming neutrino physics experiment that will answer some of the most compelling questions in particle physics and cosmology. The DUNE far detectors employ silicon photomultipliers (SiPMs) to detect light produced by charged particles interacting in a large liquid argon time projection chamber (LarTPC).
The SiPMs are photosensors consisting of an array of single-photon avalanche diodes (SPAD) operating in Geiger mode. Their high sensitivity and dynamic range, as well as the possibility to fill large surfaces with high-granularity sensors, makes them an ideal choice for DUNE. An international consortium of research groups is currently engaged in a systematic comparison of the performances of the SiPM models that have been custom developed for DUNE by two manufacturers. Such detailed studies, which include gain measurements and a structure study of the dark count rate at 77 K, are meant to determine the best choice of the photodetection system for DUNE, as well as characterize the response of the chosen detectors for the DUNE simulation. Moreover, an investigation of a newly observed phenomenon, in which quick bursts of tens of events at close range are collected in individual SiPMs, is being carried out, which potentially impacts the design of future models and their implementation in particle physics experiments.
This poster reports the main results in terms of characterization of the SiPMs that will be employed in DUNE, as well as of our studies of the novel bursts phenomenon.Speaker: Alessandro Minotti (INFN - University of Ferrara) -
19:15
Cherenkov Telescope Array sensitivty to branon dark matter models 15m
TeV DM candidates are gradually earning more and more attention within the community. Among others, extra-dimensional brane-world models may produce thermal DM candidates with masses up to 100 TeV, which could be detected with the next generation of very-high-energy gamma-ray observatories such as the Cherenkov Telescope Array (CTA). In this work, we study the sensitivity of CTA to branon DM via the observation of dwarf spheroidal galaxies. We computed annihilation cross section values needed to reach a 5σ detection as a function of the branon mass. Additionally, in the absence of a predicted DM signal, we obtained 2σ upper limits on the annihilation cross section. These limits lie 1.5−2 orders of magnitude above the thermal relic cross section value. Yet, CTA will allow to exclude a significant portion of the brane tension-mass parameter space in the 0.1−60 TeV branon mass range, and up to tensions of ∼10 TeV. More importantly, CTA will significantly enlarge the region already excluded by AMS and CMS, and will provide valuable complementary information to future SKA radio observations.
[Based on JCAP 10 (2020) 041, arXiv:2006.16706]Speaker: Alejandra Aguirre-Santaella (IFT UAM-CSIC) -
19:15
Concept, status, and performance of the AMoRE-I detectors 15m
AMoRE is an international project to search for neutrinoless double beta decay of $^{100}$Mo with enriched Molybdenum-based crystals that are instrumented for phonon-scintillation detection. AMoRE-I, the present phase of the project, utilizes thirteen $^{48depleted}$Ca$^{100}$MoO$_4$ and five Li$_2$$^{100}$MoO$_4$ crystals with a total mass of 6.2 kg with heat and light detection channels and situated in a dilution refrigerator system located at the Yangyang underground laboratory. The simultaneous detection of phonon and scintillation light signals with metallic magnetic calorimeter (MMC) read-outs provides high-quality energy and time resolutions and the capability for distinguishing between alpha- and electron-induced events. We will present the performance and preliminary analysis results of the AMoRE-I data.
Speaker: Han Beom Kim (Insttitute for Basic Science, Seoul National University) -
19:15
Cosmogenic background suppression for the ICARUS detector using a concrete overburden 15m
The ICARUS detector will search for LSND like neutrino oscillations exposed at shallow depth to the FNAL BNB beam in the context of the SBN program. In the approved FNAL SBN experiment the impact of cosmic rays is mitigated by a $4\pi$ Cosmic Ray Tagger (CRT) detector encapsulating the TPCs inside the pit and by a ~3 m concrete overburden both for the near and the far detectors. Cosmic backgrounds rejection is particularly relevant for the ICARUS detector. Due to its larger size and distance from target compared to SBND, in ICARUS the neutrino signal/cosmic background ratio is 40 times more unfavorable with in addition a greater than 3 times larger out-of-spill comics rate. In this talk, I will be addressing the question of a problematic background to genuine neutrino events especially into the electron neutrino appearance analysis by a detailed MonteCarlo calculation of the cosmic rays crossing the ICARUS detector.
Speaker: Biswaranjan Behera (Colorado State University ) -
19:15
Dark Matter Physics in Neutrino Telescopes and Neutrino Physics in Dark Matter Detectors. 15m
It is often the case that experiments built with a focus on a specific fundamental question are also sensitive to a wider range of physical phenomena. In this talk I will discuss two such cases. First, I will follow JCAP 05 (2021) 054, which assesses what simple dark matter models will be uniquely probed by a Neutrino telescope similar to KM3NeT. Given the existing constraints from $\gamma$-ray telescopes, measurements of the cosmic microwave background and direct dark matter detection, we mention a secluded $U(1)_{L_{\mu}-L_{\tau}}$ model as particularly promising. Secondly, I will follow arXiv:2104.03297, which describes how detecting solar neutrinos in direct detection experiments will be vital for distinguishing between possible $U(1)$ explanations of the anomalous magnetic moment of the muon.
Speaker: Andrew Cheek (CP3, UCL) -
19:15
Data analysis strategy used for the detection of CNO solar neutrinos with Borexino 15m
Borexino is a large liquid scintillator experiment located at the underground INFN Laboratori Nazionali del Gran Sasso, in Italy. It was designed and built with the primary goal of real-time detection of low energy solar neutrinos, and in more than ten years of data taking it has measured all the neutrino fluxes produced in the proton-proton-chain, i.e. the main fusion process accounting for ~99% of the energy production in the Sun. Recently, after improvements and developments in both hardware and software, Borexino has provided the first observation of solar neutrinos emitted from the subdominant Carbon-Nitrogen-Oxygen (CNO) fusion cycle. One of the key aspects of the analysis is the effectiveness and the performances of the multivariate fitting technique adopted to disentangle the neutrino signals from the backgrounds present in the detector. All the crucial steps of the analysis strategy adopted to extract the interaction rate of CNO neutrinos will be described in this poster.
Speaker: Luca Pelicci (Forschungszentrum and RWTH University) -
19:15
Detection prospects for the double-beta decays of $^{124}$Xe 15m
The isotope $^{124}$Xe is exceedingly rare and long-lived. Still, its two-neutrino and neutrinoless double-weak decays offer exciting opportunities for neutrino and nuclear physics. The double-weak decays with neutrinos provide constraints for nuclear matrix element calculations on the proton-rich side of the nuclear chart [C. Wittweg, B. Lenardo, A. Fieguth and C. Weinheimer, EPJ C 80 (2020) 1161]. What makes $^{124}$Xe special is the theoretical possibility of three different neutrinoless decay modes – either via double-electron capture in a nuclear resonance, or involving the emission of one or two positrons. These decays could be a key to understanding the mass and nature of the neutrino as well as the dominance of matter over antimatter in the Universe. Together with the observation of neutrinoless double-beta decays in other isotopes, $^{124}$Xe could allow to disentangle the underlying decay mechanism. The poster will introduce the neutrinoless and two-neutrino decays of $^{124}$Xe and discuss the detection prospects with upcoming experiments such as LZ, XENONnT, nEXO and DARWIN.
Speaker: Christian Wittweg (University of Zürich) -
19:15
Development of low-background NaI(Tl) crystals for the COSINE-200 experiment 15m
COSINE-100 is a WIMP dark matter search experiment using ultra low-background NaI(Tl) crystals as a goal to revisit DAMA/LIBRA experiment. COSINE-100 is running with a 106 kg array of low-background NaI(Tl) crystals with approximately 3 counts/kg/day/keV, which is about three times higher than DAMA/LIBRA’s crystals. For the unambiguous conclusion of the DAMA/LIBRA's observation, it is essential to have lower background crystals at least at the level of the DAMA/LIBRA crystals. The Center for Underground Physics (CUP) has been growing low-background NaI(Tl) crystals since 2018 for COSINE-200, and succeeded to produce low-background Tl-doped crystals. We also developed crystal machining, polishing, and detector assembly techniques as well. Home-made detectors were tested at the Yangyang underground laboratory.
In this presentation, the CUP-grown crystals and their performance will be discussed.
Speaker: Byungju Park (Univ of Science and Technology) -
19:15
Dirac and Majorana neutrino oscillations in magnetized moving and polarized matter 15m
It was shown for the first time in [1] that neutrino spin and spin-flavor oscillations can be engendered by weak interactions of neutrinos with a medium in the case when there are the transversal matter currents or transversal matter polarization. The existence of these effects was confirmed in [2]. In [3,4] we developed the quantum treatment of these phenomena and different possibilities for the resonance amplification of oscillations were discussed, the neutrino standard and also non-standard interactions were accounted for. In the present paper we further develop the quantum theory of neutrino spin and spin-flavour oscillations in moving magnetized matter with a special focus on the effects of matter polarization. Both the case of Dirac and Majorana neutrinos are considered. As an astrophysical application we consider the effect of the electron matter component polarization generated by strong magnetic field of a neutron star. This research has been supported by the Interdisciplinary Scientific and Educational School of Moscow University “Fundamental and Applied Space Research” and also by the Russian Foundation for Basic Research under Grant No. 20-52-53022-GFEN-a.
[1] A. Studenikin, Neutrinos in electromagnetic fields and moving media, Phys. At. Nucl. 67 (2004) 993.
[2] A. Kartavtsev, G. Raffelt, H. Vogel, Neutrino propagation in media: Flavor, helicity, and pair correlations, Phys. Rev. D 91 (2015) 125020.
[3] P. Pustoshny, A. Studenikin, Neutrino spin and spin-flavor oscillations in transversal matter currents with standard and non-standard interactions, Phys.Rev. D98 (2018) 113009.
[4] P. Pustoshny, V. Shakhov, A. Studenikin, Neutrino spin and spin-flavor oscillations in matter currents and magnetic fields, PoS EPS-HEP2019 (2020) 429.Speaker: Vadim Shakhov (Physical faculty of Moscow state university) -
19:15
Directional measurement in Borexino: Calibration of Cherenkov photons in a liquid scintillator detector using gamma sources 15m
Borexino is a 280-ton liquid scintillator detector located at the Laboratori Nazionali del Gran Sasso (LNGS), Italy. The main goal of Borexino is to measure solar neutrinos via elastic scattering off electrons in the liquid scintillator. The electrons are then detected by the photo-multiplier tubes via isotropically emitted scintillation photons. However, in the first few nanoseconds after a neutrino interaction, Cherenkov photons (< 1% of all detected photons) are also produced in the scintillator for electrons with kinetic energy ≥ 0.16 MeV. It is possible to obtain the $^{7}$Be solar neutrino rate in Borexino, purely based on the direction of the detected Cherenkov photons with respect to the Sun’s position. The major systematic effect for this analysis arises from the lack of a dedicated calibration for the effective refractive index of Cherenkov photons in the liquid scintillator. Therefore, in Borexino, we obtain this through gamma calibration sources namely, $^{40}$K and $^{54}$Mn. A group velocity correction estimated through the gamma sources is then used for the solar neutrino analysis. This poster will discuss the analysis strategy and methods used for this calibration, and provide motivation for a dedicated Cherenkov calibration in next-generation liquid scintillator detectors.
Speaker: Sindhujha Kumaran (IKP-2 Forschungszentrum Jülich and RWTH Aachen University) -
19:15
Electromagnetic effects in elastic neutrino scattering on nucleons and nuclei 15m
Electromagnetic properties of neutrinos can be a manifestation of new physics [1].
We study the electromagnetic contribution to elastic neutrino-nucleon and
neutrino-nucleus scattering processes. Following our approach developed for the
case of elastic neutrino-electron [2] and neutrino-proton [3] collisions, in our
formalism we account for possible electromagnetic form factors of massive
neutrinos: the charge, magnetic, electric, and anapole form factors of both diagonal
and transition types. When treating the nucleon electromagnetic vertex, we take
into account not only the charge and magnetic form factors of a nucleon, but also
its electric and anapole form factors. We examine how the effects of the neutrino
electromagnetic properties (in particular, charge radii and magnetic moments) can
be disentangled from those of the strange quark contributions to the nucleon’s
weak neutral current form factors. We also study how the neutrino electromagnetic
form factors can reveal themselves in coherent elastic neutrino-nucleus scattering.
For illustration, we present our results in the case of the 40Ar nuclear target and
neutrino energies typical for the COHERENT experiment.This work is supported by Scientific and Educational School of Moscow State
University “Fundamental and Applied Space Research” and by the Russian
Foundation for Basic Research under grant no. 20-52-53022-GFEN-A.[1] C. Giunti and A. Studenikin, Neutrino electromagnetic interactions: A window
to new physics, Rev. Mod. Phys. 87, 531 (2015), arXiv:1403.6344.
[2] K. Kouzakov and A. Studenikin, Electromagnetic properties of massive
neutrinos in low-energy elastic neutrino-electron scattering, Phys. Rev. D 96,
099904 (2017), arXiv:1703.00401.
[3] K. Kouzakov, F. Lazarev, and A. Studenikin, Electromagnetic neutrino
interactions in elastic neutrino-proton scattering, PoS (ICHEP2020) 205Speaker: Fedor Lazarev (Moscow State University) -
19:15
ENUBET: a monitored neutrino beam for the precision era of neutrino physics 15m
The ENUBET experiment, included in the CERN Neutrino Platform effort as NP06/ENUBET, is developing a new neutrino beam based on conventional techniques in which the flux and the flavor composition are known with unprecedented precision ($\mathcal{O}$(1%)). Such a goal is accomplished monitoring the associated charged leptons produced in the decay region of the ENUBET facility. Positrons and muons from kaon decays are measured by a segmented calorimeter instrumenting the walls of the decay tunnel, while muon stations after the hadron dump can be used to monitor the neutrino component from pion decays. Furthermore, the narrow momentum width (<10%) of the beam provides a precise measurement ($\mathcal{O}$(10%)) of the neutrino energy on an event by event basis, thanks to its correlation with the radial position of the interaction at the neutrino detector. ENUBET is therefore an ideal facility for a high precision neutrino cross-section measurement at the GeV Scale, that could enhance the discovery potential of the next-generation of long baseline experiments. It is also a powerful tool for testing the sterile neutrino hypothesis and to investigate possible non-standard interactions.
In this contribution the design of the beamline and of the monitoring instrumentation will be shown. A new improved design of the proton target and of the meson transfer line ensures a larger neutrino flux while preserving a purity in the lepton monitoring similar to the one previously achieved. A demonstrator of the instrumented decay tunnel is currently being built and will be exposed to particle beams at CERN in 2022 to prove the effectiveness of the approach. Progress on the full simulation of the ENUBET facility and of the lepton reconstruction, towards the full assessment of neutrino flux systematics, will be also reported, together with the physics potential of the ENUBET beam.
Speaker: Fabio Iacob (Univ Padova and INFN-Padova) -
19:15
Icecube PeV events and NSI: Role of Charged Higgs 15m
Extensions of the Standard Model with charged Higgs, having a non-negligible coupling with neutrinos, can have interesting implications vis-à-vis neutrino experiments. Such models can leave their footprints in the ultra-high energy neutrino detectors like IceCube in the form of neutrino non-standard interactions (NSIs) which can also be probed in lower energy neutrino experiments. We consider a model based on the neutrinophilic two-Higgs doublets and study its imprints in the recently reported excess neutrino events in the PeV energy bins at the IceCube. An additional signature of the model is that it also leads to sizeable NSIs. We perform a combined study of the latest IceCube data along with various other constraints arising from neutrino experiments e.g., Borexino, TEXONO, COHERENT, DUNE, and T2HK, together with the limits set by the LEP experiment, and explore the parameter space which can lead to a sizeable NSI.
Speaker: Soumya Sadhukhan (Ramakrishna Mission Residential College, Kolkata, India and Vivekananda Centre for Research) -
19:15
LAPPD deployment in the ANNIE experiment 15m
The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) experiment is a 26-ton gadolinium-loaded water Cherenkov detector located on the Booster Neutrino Beam at Fermilab. The experiment has a two-fold motivation: to perform a physics measurement and to advance new detector technologies. The measurement of final state neutron multiplicity from neutrino interactions in water as a function of momentum transfer will lower systematic uncertainties for future long-baseline neutrino experiments. The experiment is currently commissioning large-area picosecond photodetectors (LAPPDs) that will improve time and spatial resolution. This marks the first usage of LAPPDs in a physics experiment. I will present some of the on-going work towards testing, characterization, and deployment of LAPPDs.
Speaker: Venkatesh Veeraraghavan (Iowa State University) -
19:15
Low Threshold Germanium Detectors for Neutrino-Nucleus Elastic Scattering and the Studies of its Quantum-Mechanical Coherency Effects 15m
Neutrino Nucleus Elastic Scattering ($\nu A_{el}$) offers a unique laboratory to study Quantum Mechanical superpositions in electroweak interactions, towards which several experimental programs are being actively pursued. In the TEXONO experiment, we are currently focused to measure the $\nu A_{el}$ cross-section for the reactor neutrinos (E$_\nu$ <10 MeV) at Kuo-Sheng Reactor Neutrino Laboratory (KSNL) ${[1]}$. We are using the state-of-art point contact Germanium detector technology with the advance pulse-tube electro-cool mechanism to probe this small nuclear recoil process. We will report our status and plan for achieving low threshold & background with Germanium detectors at KSNL. We also identified a new parameter ($\alpha$) to describe the degree of coherency in $\nu A_{el}$, which depends on incoming neutrino energy, detector threshold, and target nucleus $[2]$. The description of $\nu A_{el}$ process in terms of $\alpha$ is complementary to the conventional descriptions with nuclear form factors based on the many-body physics in the nucleon-nucleus interplay. We derive three possible formulations to measure $\alpha$, based on (a) Nuclear Physics (b) Quantum Mechanical description and (c) Data driven description $[3]$. We found that coherency is mostly complete ($\alpha$ >95%) for $\nu A_{el}$ with reactor and solar neutrinos for Xe/CsI, Ge and Ar targets, whereas coherency is only partial for DAR-$\pi$ and weak for atmospheric neutrinos. Accordingly, studies of $\nu A_{el}$ with different neutrino sources provide complementary information and cover the transitions from completely coherent to decoherent states. We also exclude the complete coherency and decoherency conditions for COHERENT (CsI) data and project the sensitivity for reactor $\nu A_{el}$ with Ge detector.
- Research program towards observation of neutrino-nucleus coherent
scattering., H. T. Wong et al., J. Conf. Ser. 39, 266 (2006). - Coherency in neutrino-nucleus elastic scattering., S. Kerman et al., Phys. Rev. D93, 113006 (2016).
- Studies of quantum-mechanical coherency effects in neutrino-nucleus elastic scattering. V. Sharma et al., Phys. Rev. D 103, 092002 (2021).
Speaker: Vivek Sharma (Institute of Physics, Academia Sinica, Taipei, Taiwan) - Research program towards observation of neutrino-nucleus coherent
-
19:15
Measurement of the quenching factor in NaI(Tl) scintillator for dark matter search 15m
The PICOLON (Pure Inorganic Crystal Observatory for Low energy Neutr(al)ino) experiment is searching for WIMP dark matter with ultra-pure NaI(Tl) crystals at the underground laboratory in Kamioka observatory. Here, the quenching factor (QF) is the scintillation light yield ratio of nuclear recoil and electron recoil at the same energy deposit, and the QF of the NaI(Tl) is required to determine the WIMP sensitivity.
To measure QF, we irradiated NaI(Tl) scintillator with 2.45-MeV monochromatic neutrons produced by the deuteron-deuteron fusion. Scattered neutrons from NaI(Tl) were detected with liquid scintillator modules placed at scattering angles of 30, 45, and 60 degree. By removing the backgrounds with the techniques of pulse shape discrimination (PSD) and time of flight (TOF), nuclear recoil spectrum depending on the scattering angle was determined.
In this paper, we report QFs calculated from the nuclear recoil spectrum and the Geant4 simulation, comparison with the results of other groups, and prospects.Speaker: Yusuke Urano (Department of Science and Technology, Tokushima University, Tokushima, Tokushima, Japan) -
19:15
Neutrino magnetic moments in low-energy neutrino scattering on condensed matter systems 15m
Neutrino scattering on condensed matter systems at low-energy transfer can serve both as a tool for searching the BSM physics, for example, such as neutrino electromagnetic interactions [1], and as a test of the Standard Model at low-energy scale [2]. In the case of low-energy elastic neutrino scattering by electrons and nuclei in a liquid or a solid target, it is necessary to take into consideration collective effects in the electron and nuclear subsystems of the target. We develop the corresponding theoretical apparatus which is based on the formalism of the density-density and current-current Green’s functions. Calculations in the case of a superfluid He-4 target are presented to show the roles of neutrino magnetic moments and collective excitations. Our results can be used in the search of neutrino electromagnetic interactions in future low-energy neutrino scattering experiments with liquid or solid targets [2].
This research has been supported by the Interdisciplinary Scientific and Educational School of Moscow University “Fundamental and Applied Space Research” and also by the Russian Foundation for Basic Research under Grant No. 20-52-53022-GFEN-a. The work of GD is supported by the BASIS Foundation No. 20-2-9-9-1.
[1] C. Giunti and A. Studenikin, Rev. Mod. Phys. 87, 531 (2015) [arXiv:1403.6344 [hep-ph]].
[2] M. Cadeddu, F. Dordei, C. Giunti, K. Kouzakov, E. Picciau, and A. Studenikin, Phys. Rev. D 100, 073014 (2019) [arXiv:1907.03302 [hep-ph]].Speaker: Georgy Donchenko (Lomonosov Moscow State Univ) -
19:15
Neutrino masses and leptogenesis in a L_e-L_mu-L_tau based model 15m
We present a simple extension of the Standard Model with three right-handed neutrinos in a SUSY framework, with an additional U(1) abelian flavor symmetry with a non standard leptonic charge for lepton doublets and arbitrary right-handed charges. We show how it is possible to provide the correct prediction for the mixing angles of the PMNS matrix and for the parameter with a moderate fine tuning. The baryon asymmetry of the Universe is generated via thermal leptogenesis through CP-violating decays of the heavy right-handed neutrinos. We present a detailed numerical solution of the relevant Boltzmann equations accounting for the impact of the distribution of the asymmetry in the three lepton flavors.
Speaker: Simone Marciano (Università di Roma, La Sapienza) -
19:15
Neutrino quantum decoherence engendered by neutrino decay to photons, familons and gravitons 15m
The phenomenon of neutrino oscillations emerges due to coherent superposition of neutrino mass states. An external environment can modify a neutrino evolution in a way that the coherence will be violated. Such a violation is called quantum decoherence of neutrino mass states and leads to the suppression of flavor oscillations. In our previous studies (see [1] and reference therein) we presented a new theoretical framework, based on the quantum field theory of open systems and applied it to the problem of neutrino evolution. In the present paper we present the generalized framework that enables one to consider quantum decoherence of neutrino mass states engendered by a neutrino decay to a lighter neutrino and a massless particle. We apply this framework to consider mechanisms of the neutrino quantum decoherence engendered by neutrino decay to photons, familons and gravitons. The obtained results are of interest for experiments with reactor and astrophysical neutrinos.
This research has been supported by the Interdisciplinary Scientific and Educational School of Moscow University “Fundamental and Applied Space Research” and also by the Russian Foundation for Basic Research under Grant No. 20-52-53022-GFEN-a. The work of KS is also supported by the RFBR under grant No. 20-32-90107 and by the “BASIS” Foundation No. 20-2-2-3-1. The work of MV is also supported by the “BASIS” Foundation No. 20-2-1-25-1.[1] K.Stankevich, A.Studenikin, Neutrino quantum decoherence engendered by neutrino radiative decay, Phys. Rev. D 101 (2020) 056004.
Speaker: Alexey Lichkunov (Lomonosov Moscow State University) -
19:15
New Constraints on Strongly Interacting Sub-GeV Dark Matter via Electron Scattering from a small Dual-Phase Xenon TPC 15m
We report new results on interactions of sub-GeV dark matter particles with electrons using data from a small dual-phase xenon time projection chamber operated at the Earth's surface 1. We consider scattering both on electrons and nuclei in the Earth’s crust, atmosphere, and shielding materials to compute the attenuation of the dark matter flux by the atmosphere and the 2. With an exposure of $\sim15\,\mathrm{g}\,\mathrm{days}$ and based on an ionisation-only event selection and no background subtraction, we evaluate the data in terms of various models, including interactions mediated by a heavy and ultralight dark photon as well as through an electric dipole moment 3. For the case of a heavy dark photon mediator, we exclude new parameter space for dark matter particle masses in the range $100-400\,\mathrm{MeV}$.
Speaker: Simon Buse (University of Zurich) -
19:15
New physics from oscillations: sensitivity for the DUNE near detector 15m
We study the capabilities of the DUNE near detector to probe deviations from unitarity of the leptonic mixing matrix, the 3+1 sterile formalism and Non-Standard Interactions affecting neutrino production and detection. We clarify the relation and possible mappings among the three formalisms at short-baseline experiments, and we add to current analyses in the literature the study of the νμ→ντ appearance channel. We study in detail the impact of spectral uncertainties on the sensitivity to new physics using the DUNE near detector, which has been widely overlooked in the literature. Our analysis show that this plays an important role on the results and, in particular, that it can lead to a strong reduction in the sensitivity to sterile neutrinos from νμ→νe transitions, by more than two orders of magnitude. This stresses the importance of a joint experimental and theoretical effort to improve our understanding of neutrino nucleus cross sections, as well as hadron production uncertainties and beam focusing effects. Nevertheless, even with our conservative and more realistic implementation of systematic uncertainties, we find that an improvement over current bounds in the new physics frameworks considered is generally expected.
Speaker: Salvador Urrea González (IFIC (CSIC-Univ Valencia)) -
19:15
Nuclear de-excitation associated with neutrino-carbon interactions 15m
The experimental searches for supernova relic neutrino are conducted below 30 MeV, where atmospheric neutrino interactions are the dominant background. Neutrino interactions in this low energy region have a large uncertainty due to complicated nuclear effects, for example, a momentum distribution of a nucleon in nucleus, Pauli blocking and de-excitation of a residual nucleus. Sophisticated neutrino event generators GENIE, NEUT and NuWro provide several models to predict the momentum and Pauli blocking, however, they usually do not treat the de-excitation.
It is very important to carry out a systematic study to predict the contribution of de-excitation, especially for liquid scintillator detectors like KamLAND, Borexino and JUNO since they are sensitive to measure the spectra of not only gamma-ray, but also proton, neutron, alpha.
This poster will present the study on de-excitation associated with neutrino-carbon interaction using TALYS and Geant4. TALYS which is an open source software package to simulate nuclear reactions is used to calculate branching ratios of gamma, proton, neutron and alpha emissions from excited state of residual nucleus. Geant4 is widely-used simulator, and especially G4RadioactiveDecay is a smart tool to trace decay chain event by event.
By combining two softwares, I predicted various branching ratios and spectra of produced particles via de-excitation.The relative errors for the branding ratios are also discussed using another estimation which was carried out by using SMOKER. This prediction does not depend on neutrino event generator, thus, the results can be flexibly applied to the output of all neutrino event generators mentioned above.Speaker: Seisho Abe (Tohoku University) -
19:15
Optimization of a single module of CUPID 15m
In view of the next generation experiment CUPID, many R&D tests are
ongoing to define the detector design. CUPID aims to search for
neutrinoless double beta decay in a "zero background" environment,
rejecting alpha particles thanks to the simultaneous detection of heat
and scintillation light. It is of primary importance to optimize the
light collection to perform an efficient particle identification. R&D
tests on a single module of CUPID showed promising results in terms of
light yield and background rejection. Moreover the assembly planned for
CUPID has been tested to prove the light detector performances and the
energy resolution of cubic Li2MoO4 crystals.Speaker: Alberto Ressa (La Sapienza - University of Rome) -
19:15
Primordial black holes and scotogenic dark matter 15m
We study the effect of the scotogenic dark matter on the primordial black holes (PBHs) and vice versa. We show that if the PBHs evaporate in the radiation dominant era, the upper limit of the initial mass of the PBHs M_{in} should be constrained as 10^4 < M_{in}/M_{Pl} < 10^{10} for O(1) TeV scotogenic dark matter, O(1) TeV is the most appropriate energy scale in the scotogenic model. On the other hand, if the PBHs evaporate in the PBH dominated era, a quite heavy scotogenic dark matter m_{DM} > 10^9 GeV for M_{in}/M_{Pl} \sim 10^{13} may be allowed. This talk based on arXiv:2101.01921v3 (to be published in International journal of modern physics A).
Speaker: Teruyuki Kitabayashi -
19:15
Progress of upgrading alpha-ray imaging detector in low radioactivity background 15m
We have been developing an alpha-ray detector based on a time-projection-chamber in a low radioactivity background, in order to image the radioisotope concentration on the material surface. In underground particle physics, current detectors are required massive volume of target using ultra-pure material without radioactive impurities. However, uranium or thorium impurities on the surface of the detector could be reduced fiducial volume and produced background source via emanation radon. In last conference, we provided the alpha-ray imaging detector with a sensitivity of a few $10^{-3}$ $\alpha$/cm$^2$/hr in 10cm $\times$ 10cm of effective sample area. In this work, we performed to improve the sensitivity, and we would present a current status of the upgrading alpha-ray imaging detector.
Speaker: Hiroshi Ito (Tokyo University of Tokyo) -
19:15
Pulse-Shape Discrimination in the DEAP-3600 Single-Phase Liquid-Argon Detector 15m
The DEAP-3600 detector is a large single-phase liquid-argon detector for WIMP dark matter. The experiment has run successfully at SNOLAB since 2016 and has world leading limits for WIMP-argon interactions. We use pulse-shape discrimination (PSD) to separate electromagnetic events (Ar-39 beta decay, gamma rays, ...) from the nuclear recoil events from WIMP-nuclear scattering. PSD is effective in liquid argon because the nuclear recoil events have a large density of energy deposition in the argon, resulting in preferential excitation to an Argon eximer singlet state that decays in nanoseconds, whereas electromagnetic events have a low density of energy deposition resulting in excited triplet states that decay in microseconds. We discuss the scintillation pulse shapes in DEAP-3600 and show our recent analysis of pulse-shape discrimination. At 18 keVee, we have achieved rejection of EM events with leakage of 1 part in 10^{10} with a nuclear recoil acceptance of 50%. We present these results and a detailed comparison showing the effectiveness of the prompt-fraction method and the likelihood ratio. We discuss detector effects such as long-lived TPB states and PMT afterpulsing.
Speaker: Chris Jillings (SNOLAB/Laurentian University) -
19:15
Purity monitoring for ProtoDUNE-SP 15m
The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline neutrino oscillation experiment based on liquid argon time projection chamber (LArTPC) technology. In July 2020, DUNE’s single-phase (SP) prototype ProtoDUNE-SP (PD-SP) at CERN finished its two-year Phase-1 running, which successfully collected test-beam data and cosmic ray data. A key aspect of LArTPC calibration is the lifetime of drift electrons, which corrects the charge attenuation caused by drift electrons which are captured by impurities. A purity monitor is a miniature TPC that measures the lifetime of electrons generated from the photocathode via the photoelectric effect. It enables continuous monitoring of the state of the detector, especially while filling the cryostat and when liquid argon recirculation systems are operating. The purity monitoring system in ProtoDUNE-SP Phase-1 (PD-SP-I) continuously monitored liquid argon purity throughout the entire lifetime of PD-SP-I, which was critical to the experiment’s successful commissioning, operation, and data taking. I will discuss the design, implementation, and results of purity monitors in PD-SP-I and future plans.
Speaker: Yiwen Xiao (University of California Irvine) -
19:15
Quasi-Dirac neutrinos in the linear seesaw model 15m
We implement a minimal linear seesaw model (LSM) for addressing the Quasi-Dirac (QD) behaviour of heavy neutrinos, focusing on the mass regime of $M_{N} < M_{W}$.
Here we show that for relatively low neutrino masses, covering the few GeV range, the same-sign to opposite-sign dilepton ratio, $R_{\ell \ell}$, can be anywhere between 0 and 1, thus signaling a Quasi-Dirac regime. Particular values of $R_{\ell \ell}$ are controlled by the width of the QD neutrino and its mass splitting, the latter being equal to the light-neutrino mass $m_{\nu}$ in the LSM scenario. The current upper bound on $m_{\nu_{1}}$ together with the projected sensitivities of current and future $|U_{N \ell}|^{2}$ experimental measurements, set stringent constraints on our low-scale QD mass regime. Some experimental prospects of testing the model by LHC displaced vertex searches are also discussed.Speaker: Kevin Monsalvez Pozo (IFIC (CSIC-Univ Valencia)) -
19:15
Sensitivity of the Cherenkov Telescope Array to dark subhalos 15m
In this work, we study the potential of the Cherenkov Telescope Array (CTA) for the detection of Galactic dark matter (DM) subhalos. We focus on low-mass subhalos that do not host any baryonic content and therefore lack any multiwavelength counterpart. If the DM is made of weakly interacting massive particles (WIMPs), these dark subhalos may thus appear in the gamma-ray sky as unidentified sources. A detailed characterization of the instrumental response of CTA to dark subhalos is performed, for which we use the ctools analysis software and simulate CTA observations under different array configurations and pointing strategies, such as the scheduled extragalactic survey. This, together with information on the subhalo population as inferred from N-body cosmological simulations, allows us to predict the CTA detectability of dark subhalos, i.e., the expected number of subhalos in each of the considered observational scenarios. In the absence of detection, for each observation strategy we set competitive limits to the annihilation cross section as a function of the DM particle mass. Interestingly, we find the best constraints to be reached with no dedicated observations, by just accumulating exposure time from all scheduled CTA programs and pointings over the first 10 years of operation. This way CTA will offer the most constraining limits from subhalo searches in the intermediate range between 1 − 3 TeV, complementing previous results with Fermi-LAT and HAWC at lower and higher energies, respectively. This work is based on [2101.10003] and has been developed within the CTA Consortium.
Speaker: Javier Coronado-Blázquez (IFT UAM CSIC) -
19:15
Setting limits on heavy neutral leptons using the neutrino CC events at the DUNE Near Detector. 15m
We study the impact of production of heavy neutral leptons (HNL) from meson decays on the number of neutrino charged current (CC) events that will be detected at the DUNE ND LArTPC. If the masses of the HNLs are below the kaon mass, then a decreased number of CC events at the DUNE LArTPC will be observed. This decrease is used to set upper limits on the mixing parameters of the HNLs. We find that these limits are at least 1 order of magnitude better than the current ones for masses below 1 MeV for a year of operation in neutrino mode.
Speaker: Saneli Alcides Carbajal Vigo (Pontificia Universidad Católica del Perú) -
19:15
Status of 0$\nu\beta\beta$ decay search in KamLAND-Zen800 15m
The Majorana nature of neutrinos is the key to understand the matter-antimatter asymmetry in our Universe. For now, searching for the neutrino-less double beta (0$\nu\beta\beta$) decay is the only realistic way to proof that neutrinos are Majorana particles.
The KamLAND-Zen experiment is 0$\nu\beta\beta$ decay search with $^{136}$Xe and ultra-low radioactive detector KamLAND. Since 2019, we have started the KamLAND-Zen800 Phase with 750 kg enriched xenon and are aiming to the first 0$\nu\beta\beta$ decay search in the inverted mass hierarchy. As the background rate is dramatically reduced in Zen800 Phase, evaluation of the new kind of background –xenon spallation products– becomes important.
In this presentation, we present the up-to-date status of 0$\nu\beta\beta$ analysis with KamLAND-Zen800, especially focusing on the method of investigation of xenon spallation products and plan of near-future update.Speaker: Atsuto Takeuchi (RCNS, Tohoku University) -
19:15
Synthetic data for the study of the CUORE detector response function 15m
Rare event searches share the need to isolate signal from background events, therefore experiments must develop good energy resolution detectors.
In this scenario, CUORE (Cryogenic Underground Observatory for Rare Events) exploits an array of 988 TeO$_{2}$ crystals operated as Low-Temperature Detectors (LTDs) at 10 mK. The main goal of the experiment is to search for neutrino-less double beta decay ($0\nu\beta\beta$) in $^{130}$Te. CUORE detectors show an excellent energy resolution making the experiment one of the most competitive for $0\nu\beta\beta$ searches in the world.
What I am going to present deals with the generation of synthetic data for the study of the CUORE detector response function. It is a novel technique consisting of simulations that reproduce the data acquisition by taking into account non-ideal elements, such as noise as well as the shape of the signals.
Synthetic data are processed with the CUORE official analysis software, allowing the evaluation of the analysis impact on the final results.
The goal of my work is to reproduce the peaks (in the energy spectrum) intrinsic shape and resolution linear trend as a function of energy. On one hand, the peak profile significantly deviates from a Gaussian distribution. On the other hand, the linear trend of the resolution (FWHM) as a function of energy is somewhat unexpected for LTDs.
To find contributions to both effects, I initially investigated the impact of pileup on the peak shape, identifying significant deviations with respect to a Gaussian response. Additionally, I studied the effect of pulses with variable shapes, highlighting a deviation from the Gaussian profile of the peak and an enlargement of the energy resolution comparable with observed data. Moreover, I was able to reproduce the resolution linear trend as a function of energy.
Synthetic data is the only method so far that provides a simulation, even though preliminary, of the observed peak behavior. This innovative simulation gave very promising results and proved to be an extremely effective technique for the study of the detector response function in CUORE.Speaker: Alberto Gianvecchio (UNIMIB) -
19:15
Testing non-standard neutrino interactions in (anti)-electron neutrino disappearance experiments 15m
We search for scalar and tensor non-standard interactions using (anti)-electron neutrino disappearance in oscillation data. We found a slight preference for non-zero CP violation, coming from both tensor and scalar interactions. The preference for CP violation is lead by Daya Bay low-energy data with a significance that reaches $\sim1.7\sigma$ in the global analysis (and $\sim2.1\sigma$ when considering only medium baseline reactors data) compared to the standard oscillation scenario.
Speaker: Mariano Chaves (Universidade Estadual de Campinas) -
19:15
The JUNO OSIRIS detector 15m
(Poster contribution, TAUP conference, 26.8. – 3.9.2021, Valencia, Spain)
-Tobias Sterr (1), for the JUNO OSIRIS Group
1 Eberhard Karls Universität Tübingen, Physikalisches Institut, Germany
The Online Scintillator Internal Radioactivity Investigation System (OSIRIS) is a 20-ton liquid scintillator detector currently under construction at the Jiangmen Underground Neutrino Observatory (JUNO) in Kaiping, China. OSIRIS features 76 newly developed, “intelligent PMTs” (iPMTs) surrounding a cylindrical acrylic vessel enclosed in a Cherenkov muon veto. Two calibration systems, an Automated Calibration Unit (ACU) and a laser calibration system are available. The detector will be integrated into the Liquid Handling System (LHS) of JUNO. The main purpose of OSIRIS is the monitoring of the radiopurity of the liquid scintillator during the filling phase of JUNO, measuring contamination levels of 238U, 232Th, 85Kr, 210Po and 14C. A consecutive physics phase addressing solar neutrinos and 0νββ decay is foreseen.
Speaker: Tobias Sterr (Eberhard Karls Universität Tübingen, Physikalisches Institut) -
19:15
The LZ Outer Detector 15m
The LUX-ZEPLIN (LZ) detector will consist of 7 tonnes (5.6 tonnes fiducial) of liquified xenon in a dual-phase Time Projection Chamber (TPC), which is sensitive to the nuclear recoil induced by Weakly Interacting Massive Particles (WIMPs). Among the various type of background particles, neutrons pose a great threat to the WIMPs searches due to the indistinguishable nuclear recoil. The outer detector of LZ is equipped with 17 tonnes of Gadolinium-doped Liquid Scintillator (GdLS) that captures neutrons with very high efficiency. The LZ outer detector will characterize the external background, increasing the fiducial volume of LZ by 70%. I will present the design, expected performance and current status of the LZ outer detector.
Speaker: Harvey Birch (University of Michigan) -
19:15
The optical simulation model of the DarkSide-20k Veto detector 15m
DarkSide-20k is a rare-event search experiment dedicated to finding signals of dark matter particles. The DarkSide-20k time projection chamber detector registers ionisation and scintillation signals originating from the particles interacting with the liquid argon detector medium. It is enclosed in a single-phase liquid argon neutron veto tank, equipped with Gd-loaded panels for capturing neutrons. Due to particle identification and vetoing carried out through the light signal, it is crucial to maximising the light yield. Light collection efficiency depends on various aspects of the detector, and particularly for the Veto detector, which has a photosensor coverage of the order of a per cent, the reflectivity of materials used has a big impact. To quantify the amount of collected light a comprehensive Geant4 simulation is done, which uses optical characterization data. The focus of the talk will be on a detailed description of the optics model for the Veto of the experiment.
Speaker: Cenk Turkoglu (AstroCeNT: Particle Astrophysics Science and Technology Centre) -
19:15
The search for neutrinoless positron emitting electron capture of 120Te with CUORE 15m
A novel algorithm for a Bayesian analysis of multi-site rare events
CUORE (Cryogenic Underground Observatory for Rare Events) is a ton-scale experiment located at the LNGS with the main scientific goal of searching for neutrinoless double beta decay in $^{130}$Te. The detector consists of $\mathrm{TeO}_2$ crystals operated as cryogenic calorimeters. The use of natural tellurium allows us to search for other isotopes rare decays. The neutrinoless positron emitting electron capture of $^{120}$Te (natural abundance 0.09(1)%) has a clear signature from the 511-keV annihilation $\gamma$ rays. We present an analysis of this process based on a new algorithm to perform the simultaneous spectral fit over five selected decay scenarios. Each scenario is characterized by a set of crystals simultaneously interested by a detectable energy release. We describe the background structure modeling and tests of linearity we performed on the fit algorithm. We present the limit setting sensitivity and preliminary unblinded results of this analysis, accounting for the most important systematic effects.Speaker: Alice Campani (Università degli studi di Genova) -
19:15
The Singly-Charged Scalar Singlet as the Origin of Neutrino Masses 15m
We consider the generation of neutrino masses via a singly-charged scalar singlet. Under general assumptions we identify two distinct structures for the neutrino mass matrix which are realised in several well-known radiative models. Either structure implies a constraint for the antisymmetric Yukawa coupling of the singly-charged scalar singlet to two left-handed lepton doublets, irrespective of how the breaking of lepton-number conservation is achieved. The constraint disfavours large hierarchies among the Yukawa couplings. We study the implications for the phenomenology of lepton-flavour non-universality, measurements of the 𝑊-boson mass, flavour violation in the charged-lepton sector and decays of the singly-charged scalar singlet. We also discuss the parameter space that can address the Cabibbo Angle Anomaly.
Speaker: Tobias Felkl (University of New South Wales) -
19:15
Time Projection Chambers instrumented with resistive Micromegas for the SAND near detector of DUNE 15m
The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline neutrino accelerator experiment. It aims for precise measurements of the neutrino oscillation parameters, in particular the violation of the charge-parity symmetry and the neutrino mass hierarchy. DUNE consists of a Far Detector (FD) complex with four multi-kiloton liquid argon detectors, and a Near Detector (ND) complex located close to the neutrino source at Fermilab (USA).
The ND complex regroups three different detectors among which SAND (System for on-Axis Neutrino Detection) will be the only one permanently on the neutrino beam axis.
The main purpose of SAND is to monitor in detail the emitted neutrino beam and its stability through time, a crucial characteristic to realize accurate oscillation measurements at the percent level.
SAND will reuse the superconducting magnet and the electromagnetic calorimeter of the KLOE experiment. There are currently two different designs proposed for the inner tracker, which will be a fully new object.
One of the two consists of a large 3D matrix of 1.5cm side scintillator cubes (3DST) surrounded by 3 gaseous Time Projection Chambers.
This setup allows to realize accurate beam monitoring combining the 3DST unprecedented capability of neutron detection and energy measurement with the high precision momentum resolution for charged particles offered by the TPCs. The proposed TPC design allows to reach spatial resolutions of a few hundreds of micrometers using 1cm² pads thanks to the use of resistive Micromegas technology for the charge readout. Results of prototypes testing of Micromegas modules with cosmics and test beam data will be shown, together with the expected performances of the SAND TPCs based on simulation.Speaker: Pierre Granger (CEA/Irfu) -
19:15
Transformer Networks for NOvA Event Classification 15m
NOvA is a long-baseline neutrino experiment studying neutrino oscillations with Fermilab’s NuMI beam. A convolutional neural network (CNN) that analyzes topological features is used to determine neutrino flavor in both the near and far detectors and observe the disappearance of muon neutrinos and the appearance of electron neutrinos. Alternative approaches to flavor identification using machine learning are being investigated with the goal of developing a network trained with both event-level and particle-level images in addition to reconstructed physical variables while maintaining the performance of the CNN. Such a network could be used to analyze the individual prediction importances of these inputs. An original network that uses a combination of transformer and MobileNet CNN blocks will be discussed.
Speaker: Alejandro Yankelevich (University of California at Irvine) -
19:15
Understanding the systematic effects for the directional measurement of Be-7 solar neutrinos with Borexino 15m
Borexino, located at the Laboratori Nazionali del Gran Sasso in Italy, is a liquid scintillator detector that measures solar neutrinos via their forward elastic scattering off electrons . The scintillation process of detection makes it impossible to distinguish electrons scattered by neutrinos from the electrons emitted from the decays of radioactive backgrounds. Due to the unprecedented radio-purity achieved by the Borexino detector, the real time spectroscopic detection of solar neutrinos from both the pp chain and CNO fusion cycle of the Sun has been performed. With the newly presented analysis, it is now possible for the first time, to detect solar neutrinos using the few Cherenkov photons emitted at early times, in the direction of scattered electrons with an energy threshold of 0.16 MeV in the liquid scintillator. The angle which correlates the direction of the Sun and the direction of the emitted Cherenkov photons is a key parameter to extract the Be7 neutrino signal from data. This poster will describe the strategy used in the evaluation of various systematic effects including the geometric conditions of the detector and the data selection cuts that can influence the shape of the directional angle distribution for backgrounds, which is crucial to disentangle the directional Be-7 solar neutrino signal from the isotropic background in data.
Speaker: Apeksha Singhal (IKP-2 Forschungszentrum Juelich and RWTH Aachen University) -
19:15
Using isotopically enriched detectors to perform CEvNS measurements. 15m
After the latest measurement of the CEvNS process with a LAr detector, it has been shown that this interaction can be used as a powerful tool to perform tests of both the standard model and new physics scenarios. So far, one of the biggest challenges to perform precise measurements has been the determination of systematic uncertainties related, for instance, to quenching and form factors. We propose the use of several isotopically enriched detectors exposed to the same neutrino flux to measure CEvNS with precision. By performing a simultaneous measurement with these detectors, we show that the correlation between systematic uncertainties can be used to improve the accuracy of the measurement. We illustrate this idea by studying the sensitivity of a specific array of three germanium isotopes to the characteristic $N^{2}$ dependence of the cross section of this process. The idea is applicable to neutrinos coming from Spallation Neutron Sources, as well as to reactor neutrinos, and can be extended to other target materials such as silicon and nickel.
Speaker: Gonzalo Sanchez Garcia (CINVESTAV IPN) -
19:15
Xenon doping of Liquid Argon in ProtoDUNE Single Phase 15m
Doping Liquid Argon (LAr) with Xenon is a well known technique to shift the light emitted by Argon (128 nm) to a longer wavelength to ease its detection. The largest Xenon doping test ever performed in a LArTPC was carried out in ProtoDUNE Single Phase (ProtoDUNE-SP) at the CERN Neutrino Platform. From February to May 2020, a gradually increasing amount of Xenon was injected to compensate for the light loss due to air contamination. The response of such a large TPC (770 t of Liquid Argon and 440 t of fiducial mass) has been studied using the ProtoDUNE Photon Detection System (PDS) and a dedicated setup installed before the run.
With the first, it was possible to study the total light detected in the system as a function of the xenon concentration and to characterise the light collection efficiency with respect to the track position. With the second system it was possible to disentagle the LAr (128 nm) light from the Xenon (178 nm) light using two dedicated X-Arapuca modules. The run was fully satisfactory, it was possible to measure directly the increase of the Xenon light component during doping; furthermore most of the LAr light quenched by impurities was fully recovered even at small Xenon concentration (< 20 ppm in mass), which implies an efficient energy transfer between LAr and Xe.
Xenon distribution was uniform in space and stable in time, not affecting the charge collection by the TPC. A study of the collected scintillation light as a function of the track position, performed on a sample of horizontal muons, led to the estimation of an increased Rayleigh scattering length, that improves the detector response uniformity.Speaker: Niccolo' Gallice (Università degli Studi di Milano - INFN Milano)
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Hot Topic Underground Laboratories
Chairs: Aldo Ianni & Jeter Hall
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The Boulby Underground Screening (BUGS) Facility 15m
The Boulby Underground Screening (BUGS) facility has been in operation since 2014. Initially comprising 2 low background germanium detectors, this has expanded to include now 6 low and ultra-low background germanium detectors, two XIA Ultralo-1800 detectors and will soon include a low background radon emanation assay facility. With these facilities underground and with plans for cleanliness R&D facilities on the surface we are aiming to position BUGS as a facility that offers everything needed for material characterisation in current and next generation low-background particle physics experiments. This talk will introduce the facility and discuss the current status and plans for the future.
Speaker: Paul Scovell (STFC - Boulby Underground Laboratory) -
13:45
Measurement of the neutron flux at the Canfranc Underground Laboratory with HENSA 15m
S.E.A. Orrigo, J.L. Tain, J. Agramunt, A. Algora, E. Nacher, A. Tolosa
Instituto de Física Corpuscular (IFIC), CSIC-Univ. Valencia, SpainA. Tarifeño-Saldivia, F. Calviño, N. Mont, A. De Blas, R. García, G. Cortés
Institute of Energy Technologies (INTE), Technical University of Catalonia (UPC), Barcelona, SpainL.M. Fraile, A. Domínguez Bugarín
Grupo de Física Nuclear & IPARCOS, Universidad Complutense de Madrid (UCM), Madrid, SpainD. Bemmerer, M. Grieger
Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, GermanyI. Dillmann
TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, CanadaNeutrons constitute a main limitation for experiments dealing with rare event searches underground. Even if neutrons produced by cosmic-ray muons are largely suppressed in underground laboratories, radiogenic neutrons are still produced in the rocks by (alpha,n) reactions and spontaneous fission. They have a large penetrability and can induce background signals in the detectors [1,2] affecting nuclear astrophysics, neutrino and dark matter experiments.
Therefore it is of paramount importance to measure and fully characterize the neutron flux at the experimental location. Since the neutron background in underground laboratories is low, measurements have a low rate and last for months, demanding detectors with high efficiency for neutrons, high background discrimination capability and long-term stability. These requirements are fulfilled by 3He proportional counters [2-6]. The new High Efficiency Neutron-Spectrometry Array (HENSA), based on the Bonner spheres principle [3], is composed of ten long proportional counters filled with 3He gas embedded in high-density polyethylene moderators with different thickness, achieving sensitivity to neutron energies ranging from thermal to 10 GeV.
In October 2019 we started a long-term measurement of the neutron flux with HENSA in the Hall A of the Canfranc Underground Laboratory (LSC). The aim is to measure the neutron flux and characterize the energy spectrum precisely as well as to study the long-term evolution of the neutron rate looking for possible seasonal variations. These goals are of relevance for a number of experiments at LSC investigating fundamental questions of modern physics [7,8]. The Hall A measurement campaign extended up to March 2021, demonstrating an excellent stability of the HENSA setup. Results from the campaign in Hall A will be presented for the first time at the TAUP conference.
[1] E. Aprile et al., J. Phys. G 40, 115201 (2013)
[2] J.L. Tain et al., J. Phys. Conf. Series 665, 012031 (2016)
[3] D.J. Thomas and A.V. Alevra, Nucl. Instr. Meth. A 476, 12 (2002)
[4] D. Jordan et al., Astrop. Phys. 42, 1 (2013)
[5] D. Jordan et al., Astrop. Phys. 118, 102372 (2020)
[6] M. Grieger et al., Phys. Rev. D 101, 123027 (2020)
[7] A. Ianni, J. Phys. Conf. Series 718, 042030 (2016)
[8] LSC Annual Report (2018)Speaker: Sonja Orrigo (IFIC (CSIC-Univ Valencia)) -
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CUTE : A Cryogenic Underground Test Facility at SNOLAB 15m
Operational since 2019, the Cryogenic Underground TEst (CUTE) facility is located 2 km underground in the SNOLAB laboratory near Sudbury Ontario, Canada. Although designed with the focus of performance testing cryogenic (~ 10 mK) detectors for the Super Cryogenic Dark Matter Search (SuperCDMS), CUTE also makes available a well shielded and vibrationally isolated underground platform for other cryogenic detectors or projects which may benefit from such a low background underground facility. The main features and performance of the CUTE facility will be discussed, as well as some examples of devices and detectors which have been or are planned to be tested at CUTE.
Speaker: Andrew Kubik (SNOLAB)
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Hot topic Dark Matter: 2
Chairs: Susana Cebrián (1), Riccardo Catena (2), Roberto Santorelli (3)
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Annual modulation results from three-year exposure of ANAIS-112 15m
ANAIS-112 is a dark matter direct detection experiment that operates 112 kg of NaI(Tl) scintillators at the Canfranc Underground Laboratory (LSC, Spain). Its main goal is to test in a model independent way one of the most puzzling results in the present particle physics scenario: the DAMA/LIBRA observation of an annual modulation in the detection rate compatible with that expected for dark matter. This signal is in strong tension with the negative results of other very sensitive experiments. However, until recently a direct comparison using the same target material (NaI(Tl)) was lacking.
ANAIS-112 has been taking data since August 2017 in stable conditions with excellent performance. Results from the first three years are compatible with the absence of modulation and incompatible with the DAMA/LIBRA measured modulation at more than 2.5 sigma C.L. This result supports the projected goal of reaching a 3 sigma sensitivity to the DAMA/LIBRA result for the five-year operation scheduled.
In this talk we will describe the ANAIS-112 setup, the experiment performance and the data analysis. Then we will present the results of the three-year annual modulation search and discuss the physical implications and the experiment's prospects.Speaker: Maria Martinez (CAPA-UZ) -
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Windchime: Gravitational Direct Detection of Dark Matter 15m
Recent calculations have demonstrated that we may attempt the direct detection of dark matter in the laboratory through gravitational interaction alone. This is in particular relevant around the well-motivated Planck mass scale (10^19 GeV or 22 micro-gram). The Windchime collaboration is working towards a large array of dedicated sensors, based on MEMS accelerometers. Paired with quantum-enhanced readout including squeezed light sources and quantum back-action evasion, such an experiment may ultimately realize this exciting sensitivity. In the meantime, searches for ultra-light (<10^-10 eV) dark matter candidates provide an interesting application of our detector prototypes. In this talk, I will present the idea of Windchime, our prototype setups, as well as recent developments of sensors, quantum readout, simulations, and analysis frameworks.
Speaker: Rafael Lang (Purdue University) -
14:00
New Results from a Three-Year Annual Modulation Search with COSINE-100 15m
COSINE-100 is a direct detection dark matter experiment that is testing DAMA/LIBRA's claim of dark matter discovery. Located in South Korea's Yangyang Underground Laboratory, COSINE-100 comprises 106 kg of sodium iodide detectors surrounded by a ~2000 L liquid scintillator veto. In this talk, I will present new results from an annual modulation search using three years of data and the impact on DAMA/LIBRA's discovery claim. I will also discuss improvements over our previous modulation analysis, including lowering the analysis threshold to 1 keV and the development of a more robust time-dependent background model. In addition, I will review ongoing R&D projects for, and the physics reach of future phases of the experiment.
Speaker: William Thompson (Yale University)
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13:30
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13:30
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14:15
Hot topic HE astrophys. & CRs/Multi-messenger astronomy: 1
Chairs: Ioana Maris (1), Miquel Ardid (2)
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13:30
Latest results form LHAASO Observatory 15m
The recent release of a Nature paper on twelve Galactic sources, and the detection of photons up to 1.4 PeV revealed the enormous physics potential of LHAASO.
In this contribution, we will briefly illustrate the LHASSO Observatory and its potential and latest published results.Speaker: Domenico della Volpe (Université de Genève) -
13:45
Line of sight PeV-EeV neutrinos from gamma-ray blazars due to ultrahigh-energy cosmic-ray propagation 15m
Blazars are potential candidates of cosmic-ray acceleration up to ultrahigh energies (𝐸 > 1 EeV). For an efficient cosmic-ray injection from blazars, 𝑝𝛾 collisions with the extragalactic background light (EBL) and cosmic microwave background (CMB) can produce neutrino spectrum with peaks near PeV and EeV energies, respectively. We analyze the contribution of these neutrinos to the diffuse background measured by the IceCube neutrino observatory. The fraction of neutrino luminosity originating from individual redshift ranges is calculated using the distribution of BL Lacs and FSRQs provided in the Fermi-LAT 4LAC catalog. Furthermore, we use a luminosity dependent density evolution to find the neutrino flux from unresolved blazars. The results obtained in our model indicate that as much as ≈10% of the flux upper bound at a few PeV energies can arise from cosmic-ray interactions on EBL. The same interactions will also produce secondary electrons and photons, initiating electromagnetic cascades. The resultant photon spectrum is limited by the isotropic diffuse 𝛾-ray flux measured between 100 MeV and 820 GeV. The latter, together with the observed cosmic-ray flux at $𝐸>10^{16.5}$ eV, can constrain the baryonic loading factor depending on the maximum cosmic-ray acceleration energy.
Speaker: Soebur Razzaque (University of Johannesburg Centre for Astro-Particle Physics) -
14:00
TA, TALE and TAx4, Latest Results 15m
The Telescope Array (TA) is an ultra-high energy cosmic ray detector, the largest in the Northern Hemisphere, sensitive to cosmic rays with energies from 1 PeV to above 100 EeV. The main detector is a hybrid detector consisting of an array of 507 surface detectors covering 700 km$^2$ overlooked by three fluorescence telescope detector stations. The energy range has been extended at the low end by the TA Low Energy (TALE) extension consisting of fluorescence detector stations with higher elevation viewing angle and an infill array of surface detectors. At the lowest energies, around 1 PeV, the TALE fluorescence telescopes operate as imaging air Cherenkov telescopes and work in hybrid with the Non-Imaging Cherenkov (NICHE) array for hybrid Cherenkov observation. TA is also being extended at the highest energies by increasing the covered area by a factor of four in the TAx4 project. In this presentation, we will present the latest results from TA including a measurement of the spectrum and anisotropy studies, nuclear composition results from TALE, and the first results from TAx4.
Speaker: Douglas Bergman (University of Utah)
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13:30
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14:15
Hot topic Neutrinos: 2
Chairs: Silvia Capelli (1), Ninetta Saviano (2)
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13:30
Probing secret interactions of astrophysical neutrinos in the high-statistics era 15m
Do neutrinos have sizable self-interactions? This fundamental question, whose answer directly affects future precise astrophysical and cosmological observations, is difficult to directly test in the laboratory. For the last years, neutrino telescopes have been identified as unique tools to explore neutrino self-interactions. The actual discovery of astrophysical neutrinos and the advent of future neutrino telescopes, together with a more precise understanding of neutrino masses from laboratory and cosmological probes, calls for a robust theoretical description of the underlying particle physics and its connections with other neutrino observables. In this work, we set up such theoretical framework for present and future studies. We quantify the relevance of previously ignored effects, and we clarify the interplay with other experimental probes of neutrino properties. These directly affect the interpretation of present data in terms of self-interactions, as well as the testability of current "hints" in future facilities. After applying our formalism, we find that current IceCube data shows no evidence of neutrino self-interactions, and it is beginning to exclude self-interactions that have been argued to affect cosmological parameter extraction (most notably $H_0$). Furthermore, our results show that the future IceCube Gen2 observatory should be sensitive to many cosmologically relevant neutrino self-interaction models.
Speaker: Iván Esteban (CCAPP, Ohio State University) -
13:45
IceCube constraints on Violation of Equivalence Principle 15m
Among the information provided by high energy neutrinos, a promising possibility is to analyze the effects of a Violation of Equivalence Principle (VEP) on neutrino oscillations. We analyze the IceCube data on atmospheric neutrino fluxes under the assumption of a VEP and obtain updated constraints on the parameter space with the benchmark choice that neutrinos with different masses couple with different strengths to the gravitational field. In this case we find that the VEP parameters times the local gravitational potential at Earth can be constrained at the level of $10^{-27}$. We show that the constraints from atmospheric neutrinos strongly depend on the assumption that the neutrino eigenstates interacting diagonally with the gravitational field coincide with the mass eigenstates, which is not a priori justified: this is particularly clear in the case that the basis of diagonal gravitational interaction coincide with the flavor basis, which cannot be constrained by the observation of atmospheric neutrinos. Finally, we quantitatively study the effect of a VEP on the flavor composition of the astrophysical neutrinos, stressing again the interplay with the basis in which the VEP is diagonal: we find that for some choices of such basis the flavor ratio measured by IceCube can significantly change.
Speaker: Damiano F.G. Fiorillo (University of Naples "Federico II") -
14:00
Fast neutrino flavor conversion induced by the coherent backward scatterings in the core-collapse supernovae 15m
In the environment with dense neutrino gases such as in core-collapse supernovae (CCSNe), the neutrino self-interactions are potentially dominant, and collective flavor conversions occur near the core. In particular, the crossings in the neutrino angular distribution can induce fast flavor conversion. The coherent scatterings off heavy nuclei in the preshock region of CCSNe can create tiny negative crossings in the backward direction and lead to fast instability. We demonstrate the flavor evolution triggered by the fast instability and a cascade due to the nonlinear effects.
Speaker: Masamichi Zaizen (University of Tokyo)
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13:30
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15:00
Dark matter models (theory review) 30m
Chair: Masaki Yamashita
Speaker: Maxim Pospelov (Univ Minnesota) -
15:00
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15:30
Direct detection of dark matter (experimental review) 30m
Chair: Masaki Yamashita
Speaker: Marc Schumann (Univ Freiburg) -
15:30
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16:00
Break 30m
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16:00
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Axions as dark matter (theory & exp) 30m
Chair: Jodi Cooley
Speaker: Javier Redondo (Univ Zaragoza) -
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17:00
Light dark matter (theory & exp) 30m
Chair: Jodi Cooley
Speaker: Yonit Hochberg (Hebrew U, Jerusalem) -
17:10
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Discussion Panel Cosmology 2
Chair: Maria Archidiacono
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17:10
Massive Neutrino Self-interactions and The Hubble Tension 15m
Based on: JCAP 03 (2021) 084 (arXiv: 2012.07519)
We have updated the constraints on flavour universal neutrino self-interactions mediated by a heavy scalar, in the effective 4-fermion interaction limit. We use the relaxation time approximation to modify the collisional neutrino Boltzmann equations, which is known to be very accurate for this particular scenario. Based on the latest CMB data from the Planck 2018 data release as well as auxiliary data we confirm the presence of a region in parameter space with relatively strong self-interactions which provides a better than naively expected fit. However, we also find that the most recent data, in particular high-$\ell$ polarisation data from the Planck 2018 release, disfavours this solution even though it cannot yet be excluded. Our analysis takes into account finite neutrino masses (parameterised in terms of $\sum m_{\nu}$) and allows for a varying neutrino energy density (parameterised in terms of $N_{\rm eff}$), and we find that in all cases the neutrino mass bound inferred from cosmological data is robust against the presence of neutrino self-interactions. Finally, we also find that the strong neutrino self-interactions do not lead to a high value of $H_0$ being preferred, i.e. this model is not a viable solution to the current $H_0$ discrepancy.Speaker: Shouvik Roy Choudhury (Indian Institute of Technology Bombay) -
17:10
Precision calculation of neutrino evolution in the early Universe 15m
In the primordial Universe, neutrino decoupling occurs only slightly before electron-positron annihilations. This leads notably to an increased neutrino energy density compared to the standard instantaneous decoupling approximation, parametrized by the effective number of neutrino species $N_\mathrm{eff}$. A precise calculation of neutrino evolution is needed to assess its consequences on BBN, structure formation or on the CMB, and requires to take into account multiple effects such as neutrino oscillations, which represents a genuine numerical challenge.
Recently, several improvements have been made towards such a precision calculation, leading to the new reference value $N_\mathrm{eff}=3.0440$. We have managed to get a deeper understanding of the role of flavour oscillations, which has led to a new approximation of neutrino evolution, which exploits the large difference between the oscillation time scale and the kinetic evolution time scale. This novel approach can be generalized to study for instance the evolution of neutrino asymmetries in the early universe, allowing to perform a proper 3-neutrino calculation using the full collision term.
Speaker: Julien Froustey (Institut d'Astrophysique de Paris) -
17:25
Cosmological radiation density with non-standard neutrino-electron interactions 15m
Neutrino non-standard interactions (NSI) are known to modify the picture of neutrino decoupling from the cosmic plasma. These NSI alter flavour oscillations through matter effects and the annihilation and scattering between neutrinos and electrons and positrons in the thermal plasma. In view of the forthcoming cosmological observations, we perform a precision study of the impact of non-universal and flavour-changing NSI on the effective number of neutrinos, $N_{\rm eff}$. We present the variation of $N_{\rm eff}$ arising from the different NSI parameters and discuss the existing degeneracies among them, from cosmology alone and in relation to the current bounds from terrestrial experiments. We find that future cosmological data would provide competitive and complementary constraints for some of the couplings and their combinations.
Speaker: Pablo Martínez-Miravé (IFIC (CSIC-Univ Valencia)) -
17:45
BBN and CMB combined and separate constraints on new physics: measuring Neff and probing its evolution 15m
Big Bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) both probe the physics of the early universe. BBN accounts for the cosmic origin of the lightest chemical elements, such as helium-4 and deuterium. Having precisely measured nuclear data and the neutron lifetime as inputs, BBN abundance predictions depend on two cosmological parameters: the cosmic baryon-to-photon ratio $\eta = \rm n_{b}/n_{\gamma}$ (equivalent to the baryon density $\Omega_{\rm b}h^{2}$) and the effective number of standard neutrino species $\rm N_{\rm eff}$. BBN analysis has long used observed primordial abundances from astronomical observations to infer $\eta$ and $\rm N_{\rm eff}$. Crucially, both parameters are also measured independently from the CMB. Thus, the concordance between BBN and CMB determinations of these two parameters not only provides a critical test to the hot Big Bang model but also can reveal new physics.
The joint BBN+CMB constraint on $\rm N_{eff}$ is one of the key concerns in the quest for physics beyond the Standard Model (BSM). Any deviation in $\rm N_{\rm eff}$ from the Standard Model prediction would point to nonstandard cosmology and likely new physics, as a complementary cosmological approach to terrestrial particle experiments. Moreover, the BBN+CMB constraining power on new physics improves whenever new observations with unprecedented high precision are available. Latest developments of relevant BBN+CMB analyses will be discussed. Furthermore, we can search for any changes in $\eta$ and/or $\rm N_{\rm eff}$ between BBN and the CMB. This is a new probe: only recently BBN and the CMB independently reach levels of precision that can meaningfully reveal such changes. We will present likelihoods of ($\Delta \eta$, $\Delta \rm N_{\rm eff}$) that constrain a broad variety of BSM models, including extra entropy and/or radiation injection between BBN and the CMB.
Speaker: Tsung-Han Yeh (University of Illinois Urbana-Champaign) -
17:45
Intimate relationship between sterile neutrino Dark Matter and extra radiation in the early Universe 15m
keV-scale gauge-singlet fermions, allowed to mix with the active neutrinos, are elegant dark matter (DM) candidates. They are produced in the early universe via the Dodelson-Widrow mechanism and can be detected as they decay very slowly, emitting X-rays. In the absence of new physics, this hypothesis is virtually ruled out by astrophysical observations. In this talk, I will demonstrate that new interactions among the active neutrinos allow these sterile neutrinos to make up all the DM while safely evading all current experimental bounds. Neutrino interactions mediated by a sub-MeV scalar can also lead a lower bound on the amount of extra radiation in the early Universe. Such models can, therefore, receive strong constraints from next generation cosmology experiments, like CMB-S4
Speaker: Manibrata Sen (UC, Berkeley) -
17:45
Massive sterile neutrinos in the Early Universe: from thermal decoupling to cosmological constraints 15m
We consider heavy sterile neutrinos $\nu_s$ with mass in the range $10~\mathrm{MeV}≤m_s≤m_π∼135~\mathrm{MeV}$, which are thermally produced in the Early Universe, in collisional processes involving active neutrinos, and freezing out after the QCD phase transition. Notably, if these neutrinos decay after the active neutrino decoupling, they generate extra neutrino radiation and contribute to entropy production: they alter the value of the effective number of neutrino species $N_{\mathrm{eff}}$ and $^4\mathrm{He}$ production. We provide a detailed account of the numerical solution of the exact relevant Boltzmann equations. Finally, we also identify the parameter space allowed by current Planck satellite data and forecast the parameter space probed by future Stage-4 ground-based CMB observations, expected to match or surpass BBN sensitivity, improving the existing constraints on the sterile neutrino parameter space in both cases.
Speaker: Leonardo Mastrototaro (Università degli Studi di Salerno - INFN, Sezione di Napoli, Gruppo collegato di Salerno) -
17:45
Neutrino decay in precision cosmology 15m
Neutrino decay interaction with scalar majorons naturally arises from Standard Model extensions to model neutrino mass generation. The interaction if present during the CMB epoch has the potential to disrupt neutrino free streaming and hence the CMB anisotropy spectra. This has been previously studied as a cosmological constraint on neutrino lifetime. In this work, we model the decay interaction with the full collisional Boltzmann hierarchy. The result shows the lifetime constraint from neutrino decay can be relaxed by several orders of magnitude.
Speaker: Joe Zhiyu Chen (The University of New South Wales) -
17:45
Neutron-antineutron oscillations as a probe of baryogenesis 15m
An observation of Neutron-antineutron ($n-\bar{n}$) oscillations, would directly imply physics beyond the Standard Model violating baryon number by two units $|\Delta B| = 2$ and hence might provide a close link to the mechanism behind the observed baryon asymmetry of the Universe. In this talk, I will discuss the consequences of such a discovery in the near future, e.g. at the Deep Underground Neutrino Experiment or the European Spallation Source, for baryogenesis mechanisms. I will discuss both an effective field theory approach and a more concrete simplified model approach with a source of CP violation and different hierarchies between the scales of new physics. I will also highlight the complementarity of $n-\bar{n}$~oscillation searches with other experimental constraints from dinucleon decay, LHC, and meson oscillations and discuss how an observation of $n-\bar{n}$~oscillation can rule out many potential baryogenesis scenarios and favour only a select few providing an exciting possibility to understand our matter dominated Universe at laboratory.
Speaker: Chandan Hati (Technische Universität München)
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17:10
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Discussion Panel Dark Matter 3
Chair: María Martínez
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17:10
The Dark-PMT: A Novel Direction Light Dark Matter Detector Based on Vertically-Aligned Carbon Nanotubes 15m
We present the latest results on the development of the Dark-PMT, a novel light Dark Matter (DM) detector. The detector is designed to be sensitive to DM particles with mass between 1 MeV and 1 GeV. The detection scheme is based on DM-electron scattering inside a target made of vertically-aligned carbon nanotubes. Vertically-aligned carbon nanotubes have vanishing density in the direction of the tube axes, therefore the scattered electrons can leave the target without being reabsorbed only if their momentum is parallel to the tubes, which is what happens when the tubes are parallel to the DM wind. This grants directional sensitivity to the detector, a unique feature in this DM mass range. We will report on the construction of the first Dark-PMT prototype, on the establishment of a state-of-the-art carbon nanotube growing facility in Rome, and on the characterizations of the nanotubes performed in Rome with XPS and angular-resolved UPS spectroscopy.
Speaker: Francesco Pandolfi (INFN Rome) -
17:25
Directional Dark Matter Search with NEWSdm 15m
In spite of the extensive search for the detection of the dark matter (DM), experiments have so far yielded null results: they are probing lower and lower cross-section values and are touching the so-called neutrino floor. A way to possibly overcome the limitation of the neutrino floor is a directional sensitive approach: one of the most promising techniques for directional detection is nuclear emulsion technology with nanometric resolution. The NEWSdm experiment, located in the Gran Sasso underground laboratory in Italy, is based on novel nuclear emulsion acting both as the Weakly Interactive Massive Particle (WIMP) target and as the nanometric-accuracy tracking device. This would provide a powerful method of confirming the Galactic origin of the dark matter, thanks to the cutting-edge technology developed to readout sub-nanometric trajectories. In this talk we discuss the experiment design, its physics potential, the performance achieved in test beam measurements and the near-future plans. After the submission of a Letter of Intent, a new facility for emulsion handling was constructed in the Gran Sasso underground laboratory which is now under commissioning. A Conceptual Design Report is in preparation and will be submitted in Summer 2021.
Speaker: Artem Golovatiuk (Univ Naples Federico II and INFN) -
17:40
PICOLON dark matter search project 15m
COSINE-100 and ANAIS-112 are rejecting the annual modulating signal of DAMA/LIBRA. However, their background is higher than that of DAMA/LIBRA.
It is essential to verify the seasonal variations using NaI(Tl) detectors, which have a lower background than DAMA/LIBRA.PICOLON (Pure Inorganic Crystal Observatory for LOw-energy Neutr(al)ino) aims to search for cosmic dark matter by high purity NaI(Tl) scintillator.
We developed a highly pure NaI(Tl) crystal by hybrid purification method.
Our purification method was the optimized combination of recrystallization and resin methods.
The recent result of $^{210}$Pb in our NaI(Tl) is less than 5.7 $\mu$Bq/kg.The low-background measurement with highly radiopure NaI(Tl) is ongoing in Kamioka Underground Laboratory, Tohoku University.
The present detector consists of two prototype detectors, each mass is 1.3 kg.
The NaI(Tl) detector was installed into the pure copper shield and lead shield.The sensitivity for annual modulating signals and finding dark matter particles will be discussed.
Reference: K.Fushimi et al., Prog. Theor. Exp. Phys. 2021, 043F01, DOI: 10.1093/ptep/ptab020
Speaker: Ken-Ichi Fushimi (Tokushima University) -
17:45
Characterization of an ultra-high purity NaI(Tl) crystal scintillator with the SABRE Proof-of-Principle detector 15m
The SABRE (Sodium-iodide with Active Background REjection) experiment aims to detect the annual modulation of the dark matter interaction rate by means of ultra-high purity NaI(Tl) crystals immersed in a liquid scintillator (LS) active veto. It focuses on the achievement of a very low background to carry out a model-independent test of the long-standing DAMA/LIBRA result with sufficient sensitivity using the same target material. The two hemispheres approach, one detector placed at the Gran Sasso National Laboratory (LNGS), in Italy, and the other at the Stawell Underground Physics Laboratory (SUPL), in Australia, allows to disentangle seasonal or site-related effects from the dark matter annually modulated signal. The SABRE experiment has recently completed a Proof-of-Principle (PoP) phase, which was devoted to assess the radiopurity of the crystals as well as the efficiency of the LS veto. In this talk, the new results on the radiopurity of a 3.4-kg NaI(Tl) crystal scintillator grown within the SABRE Collaboration, and operated underground in the SABRE-PoP setup, will be presented and discussed. The amount of potassium content in the crystal, determined by direct counting of $^{40}$K, is found to be < 4.7 ppb at 90% C.L., lowest level ever achieved for NaI(Tl) crystals. With active veto, the average background rate in the [1-6] keV energy region-of-interest is 1.20 ± 0.05 counts/day/kg/keV, which is, for the first time, comparable with DAMA/LIBRA-phase1. Our background model indicates that the rate is dominated by $^{210}$Pb and that about half of this contamination is located in the PTFE reflector wrapped around the crystal. Ongoing developments aimed at a further reduction of radioactive contaminants in the crystal will be also discussed. A projected background rate lower than ~0.2 counts/day/kg/keV in the region-of-interest is within reach, and represents a benchmark for the development of next-generation NaI(Tl) detector arrays for the direct detection of dark matter particles.
Speaker: Ambra Mariani (Princeton University) -
17:45
COSINUS: Cryogenic NaI detectors for direct dark matter search 15m
Today, the situation in direct dark matter detection is puzzling: The DAMA/LIBRA experiment observes an annual modulation signal at high statistical significance and fitting to the expectation of a cold dark matter halo in the milky way. However, in the so-called standard scenario on dark matter halo and dark matter interaction properties, the DAMA/LIBRA signal contradicts the null-results of numerous other experiments.
COSINUS aims for a model-independent cross-check of the DAMA/LIBRA signal. To be immune to potential dependencies on the target material, COSINUS will use NaI target crystals, the same material as DAMA/LIBRA. Several experimental efforts with NaI targets are planned or already ongoing. COSINUS is the only experiment operating NaI as a cryogenic detector, which yields several distinctive advantages: Discrimination between electronic interactions and nuclear recoils off sodium and iodine on an event-by-event basis, a lower nuclear recoil energy threshold, and a better energy resolution.
In this contribution, we will sketch the current status of the COSINUS experiment, from the development of the cryogenic NaI detectors to the construction of the experimental facility at the LNGS underground laboratory.
Speaker: Florian Reindl (HEPHY (ÖAW) & TU Wien, Vienna) -
17:45
Directional Dark Matter searches with the CYGNO/INITIUM project 15m
We are going to present the CYGNO project for the development of an high precision optical readout gaseous TPC for directional Dark Matter search and solar neutrino spectroscopy, to be hosted at Laboratori Nazionali del Gran Sasso. CYGNO (a CYGNus TPC with Optical readout) fits into the wider context of the CYGNUS proto-collaboration, for the development of a Galactic Nuclear Recoil Observatory at the ton scale with directional sensitivity. CYGNO peculiar features are the use of sCMOS cameras and PMTs coupled to GEMs amplification of an Helium-based gas mixture at atmospheric pressure, in order to achieve 3D tracking with head tail capability and background rejection down to few keV energy and boost sensitivity to low WIMP masses. We will discuss the latest R&D results within the CYGNO project and the prospect for the upcoming underground installation of a 50 L prototype in Fall 2021, soon to be followed by a O(1) m$^3$ experiment in 2023-2024. We will illustrate the synergy with the ERC Consolidator Grant project INITIUM aimed at realising negative ion drift operation within the CYGNO 3D optical approach and how the reduced diffusion could boost the chosen approach towards large scale detectors.
Speaker: Elisabetta Baracchini (Gran Sasso Science Institute) -
17:45
Directionality and 3D tracks in the (sub)keV range with the MIMAC detector 15m
The detection of a dark matter (DM) particle would deeply contribute to the understanding of the Universe and would shine light on new Physics. The WIMP is an extensively studied DM candidate that would induce nuclear recoils inside a detector. The largest direct projects searching for WIMPs will soon reach the “neutrino floor”, a boundary beyond which a WIMP signal cannot be distinguished from the irreducible background due to neutrinos. The only known principle to overpass this background is to measure the direction of the induced recoils and to correlate it with the expected incoming direction of the WIMPs. This is the principle of directional detection.
In this talk we will introduce MIMAC, a directional detector that measures simultaneously the energy of a particle and reconstructs its track in 3D in an adaptable energy range [150 eV , 30 MeV]. MIMAC is a gaseous µ-TPC in which one can adapt the experimental conditions (target mass, spin, pressure, etc.) to particular DM candidates phenomenology.
We will focus on the study of directionality in the keV-range for which there is a lack of experimental data. In this low energy region, the lengths of the WIMP-induced nuclear recoils lie in the sub-millimeter range. We will show that the diffusion of the primary electrons, usually considered as a limiting phenomenon, improve our directional performances for sub-millimeter tracks! Measuring low-energy recoils implies to operate at high-gain, for which many ions are produced in the avalanche process. We have developed SimuMimac, a simulation tool that investigates the influence of the ions on the signal formation and the 3D reconstruction. SimuMimac agrees with the measurements and shines light on possible deconvolutions of the signal induced by the ions.
Low-energy electrons are of interest to understand the background but also, for instance, to search for Axion-Like Particles. In this talk we will present 3D tracks of electrons down to 150eV. At these energies, only a few primary electrons are generated by the ionization process. We will show that MIMAC is sensitive to the fluctuation of the number of primary electrons and that we can use this phenomenon to determine the gain per primary electrons.
Speaker: Cyprien Beaufort (LPSC / CNRS) -
17:45
Directionality for nuclear recoils in a liquid argon Time Projection Chamber 15m
Liquid argon (LAr) is one of the most promising targets for the search of WIMP-like dark matter. LAr dual-phase time projection chamber (LAr TPC) is a leading technology, able to detect both the scintillation and ionization signals. The correlation in the two signal channels provides a possible handle to measure the recoil direction of the nuclei: if confirmed, this would allow inferring the incident direction of potential dark matter candidates.
Previous work from SCENE resulted in a hint of the existence of a directional effect, which can potentially pave the way for a tonne scale directional WIMP search with LAr TPC. To validate this hypothesis, we conducted the Recoil Directionality (ReD) experiment to measure this correlation in 70 keV nuclear recoils to the highest precision.
The ReD TPC was carefully calibrated then irradiated with a neutron beam at the INFN Laboratori Nazionali del Sud, Catania, Italy. A model based on directional modulation in charge recombination was developed to explain the correlation. In this contribution, we describe the experimental setup, the theoretical model, and the preliminary results from data analysis.
Speaker: Xinran Li (Lawrence Berkeley National Laboratory) -
17:45
KDK: Measuring the unique third forbidden electron capture decay of K-40 for backgrounds in rare-event searches 15m
Potassium-40 (K-40) is a long-lived, naturally occurring radioactive isotope. The decay products are prominent backgrounds for many rare event searches, especially those involving NaI-based scintillators (ex. DAMA, ANAIS-112, COSINE-100, SABRE, COSINUS etc.). The branching ratio of the electron capture directly to the ground state of Argon-40 has never been experimentally measured and presents an unknown background directly in the 2-6 keV energy region. This is the same region where the DAMA/LIBRA experiment observes their unique annual modulation. Knowledge of this branching ratio can place constraints on the allowed modulation fraction observed by the DAMA experiment. In addition, this branching ratio has important implications for nuclear physics and geochronology. KDK (Potassium (K) Decay (DK)) is an international collaboration dedicated to the measurement of this branching ratio. The experiment is performed using a silicon drift detector with a thermally deposited, enriched K-40 source inside the Modular Total Absorption Spectrometer (MTAS, Oak Ridge National Laboratory). MTAS is a large NaI detector whose high gamma-ray efficiency enables the proper discrimination between ground and excited state electron capture events. This setup has been characterized in terms of energy calibration and dead time, and a tagging efficiency of 97.89(6) % has been demonstrated (arXiv:2012.15232 submitted to NIM). We report on the analysis method and sensitivity for a 44-day K-40 physics run.
Speaker: Matthew Stukel (Queen's University) -
17:45
Machine-learning techniques applied to three-year exposure of ANAIS−112 15m
ANAIS (Annual modulation with NaI(Tl) Scintillators) is a direct dark matter detection experiment aiming at the confirmation or refutation of the DAMA/LIBRA positive annual modulation signal in the low energy detection rate, using the same target and technique. ANAIS−112, located at the Canfranc Underground Laboratory in Spain, is operating an array of 3×3 ultrapure NaI(Tl) crystals with a total mass of 112.5 kg since August, 2017. The trigger rate in the region of interest (1-6 keV) is dominated by non-bulk scintillation events. In order to discriminate these noise events from bulk scintillation events, robust filtering protocols have been developed. Although this filtering procedure works very well above 2 keV, the measured rate from 1 to 2 keV is about 50% higher than expected by our background model, and we cannot discard non-bulk scintillation events as responsible of that excess. In order to improve the rejection of noise events, a Boosted Decision Tree (BDT) has been developed and applied. With this new PMT-related noise rejection algorithm, the ANAIS−112 background between 1 and 2 keV is reduced by almost 30%, leading to an increase in sensitivity to the annual modulation signal. In this talk, the reanalysis of the three years of ANAIS−112 data taking with this technique will be presented.
Speaker: Iván Coarasa (Universidad de Zaragoza) -
17:45
Quenching Factor consistency across several NaI(Tl) crystals 15m
Testing the DAMA/LIBRA annual modulation result independently of dark matter particle and halo models has been a challenge for twenty years. Using same target material, NaI(Tl), is required and presently two experiments, ANAIS-112 and COSINE-100, are running for such a goal. However, a precise knowledge of the detector response to nuclear recoils is mandatory because this is the channel where the dark matter signal is expected. The emitted light is quenched with respect to the gamma-calibrated energy by a factor that has to be measured experimentally. However, current quenching factor measurements show a disagreement within the energy region of interest for dark matter searches. To disentangle whether this discrepancy is due to intrinsic differences in the light response among different NaI(Tl) crystals, or has its origin in unaccounted for systematic effects will be key in the comparison among the different experiments. We present measurements of the quenching factors for several small NaI(Tl) crystals performed in the same experimental setup to control systematics. Nuclear recoils were produced by quasi-monoenergetic neutrons, and triggering was done by the scattered neutron interacting in one of the 17 liquid scintillator backing detectors placed at different angles from the NaI(Tl) crystal. This triggering avoids threshold effects that could have affected some of the previous experimental results. In this talk, we will present the results of our experiment and a comparison with those available in the literature. We will also analyze their effect on the annual modulation interpretation.
Speaker: David Cintas González (Universidad de Zaragoza) -
17:45
Skipper CCDs for the search of daily modulation of Dark Matter signal in the DMSQUARE experiment 15m
The Dark Matter Daily Modulation experiment (DMSQUARE) seeks for dark matter interactions with a Skipper CCD. It is currently running at surface level in Bariloche, Argentina, and will be moved to a shallow underground site at Sierra Grande, Arg, in September 2021. The low threshold achieved by Skipper CCDs allows to search for electron recoil events with an ionization energy down to 1.2 eV. In order to extract a potential dark matter signal from noise at the single electron level, we propose to search for a diurnal modulation of events, resulting from the potential interaction of the dark matter wind through the Earth. Depending on the model, mass and cross-section, this modulation can be maximum at 40deg of latitude in the Southern Hemisphere, where DMSQUARE is operated. In this talk we will present the experiment, report preliminary results with Skipper CCDs taking data at surface level and comment on future prospects for the experiment.
Speaker: Nicolás Avalos (CONICET) -
17:45
The ASTAROTH Project: enhanced low-energy sensitivity to Dark Matter annual modulation 15m
ASTAROTH is a novel R&D project which aims at improving the physics reach of future direct dark matter detection experiments based on NaI(Tl) scintillating crystals.
There is a strong need to test the long standing DAMA positive observation of an annual modulation that could be due to Dark Matter, with the same target material and in a model independent way.
ASTAROTH aim is to enhance the sensitivity to the annual modulation signal, compared to the present technology, by lowering the detection energy threshold, making it possible for the first time to observe sub-keV recoils.
This can be achieved by reading the scintillation light from the NaI(Tl) crystals with arrays of Silicon PhotoMultipliers (SiPM), and placing the detectors in a cryogenic environment.
Indeed, SiPMs feature lower dark noise than photomultiplier tubes at T<150 K and allow for a higher light collection.
The chosen cooling medium is liquid Argon, as it is an excellent scintillator that could be instrumented to act as a veto detector against several backgrounds.
Here we present the status of the ASTAROTH project: we will show the preliminary results of first measurements performed on a single NaI(Tl) read by one SiPM array in a temporary cryogenic set-up cooled with liquid nitrogen. Then, we will introduce the innovative design of the detector chamber that will be used for the demonstration of the ASTAROTH technology, and which is presently under construction and foreseen to be commissioned by the end of 2021.Speaker: Andrea Zani (INFN Milano) -
17:45
The SABRE South Experiment at the Stawell Underground Physics Laboratory 15m
The SABRE (Sodium-iodide with Active Background REjection) experiments aim to detect an annual rate modulation from dark matter interactions in ultra-high purity NaI(Tl) crystals. The SABRE south experiment is located at the Stawell Underground Physics Laboratory (SUPL), Australia, the first deep underground laboratory in the Southern Hemisphere, due to be completed in late 2021. SABRE South is designed to disentangle seasonal or site-related effects from the dark matter-like modulated signal first observed by DAMA/LIBRA in the Northern Hemisphere. It is a partner to the SABRE North effort at the Gran Sasso National Laboratory (LNGS).
SABRE South is instrumented with ultra high purity NaI(Tl) crystals immersed in a linear alkyl benzene based liquid scintillator veto, further surrounded by passive steel and polyethylene shielding and a plastic scintillator muon veto. The SABRE South experiment is under construction, and will be commissioned from late 2021 to early 2022. In this presentation we will present the final design of SABRE South, the status of its construction, its expected background, and its sensitivity to a DAMA/LIBRA like modulation. We will also present recent quenching factor measurements of sodium nuclear recoils in NaI(Tl) crystals measured with the ANU Heavy Ion Accelerator Facility, and a report on the status of SUPL.
Speaker: William Dix (Univ Melbourne)
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Discussion Panel Dark Matter 4
Chairs: Theopisti Dafni & Igor G. Irastorza
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17:10
Axion Quasiparticles for Axion Dark Matter Detection 15m
It has been suggested that certain antiferromagnetic topological insulators contain axion quasiparticles (AQs), and that such materials could be used to detect axion dark matter (DM). In the first part of this talk we show that one can detect AQs with transmission spectroscopy. The transmission coefficients including material losses are computed by applying appropriate boundary conditions. We show that by comparing our signal calculation to future THz transmission experiments the existence of AQs can be proven. Furthermore, the comparison can be used to fully characterize the material parameters.
In the second part of this talk we show that AQs can be used for axion DM detection. The dispersion relation and boundary conditions permit resonant conversion of axion DM into THz photons. The resonance frequency is tunable with an external B-field. A parameter study for axion DM detection is performed, computing boost amplitudes and bandwidths using realistic material properties including loss. The proposal could allow for detection of axion DM in the mass range between 1 and 10 meV using current and near future technology.Speaker: Jan Schütte-Engel (University of Illinois Urbana-Champaign) -
17:25
Axion-Photon Conversion in Magnetospheres: The Role of the Plasma 15m
The most promising indirect search for the existence of axion dark matter uses radio telescopes to look for narrow spectral lines generated in the magnetospheres of neutron stars. Unfortunately, a large list of theoretical uncertainties has prevented this search strategy from being accepted as robust. In this talk I will present a novel end-to-end pipeline that traces individual photon trajectories from their point of genesis in the magnetosphere to asymptotic distances. This method allows one assess many of the outstanding uncertainties, including: (1) do refraction and reflection induce strong inhomogeneous features in the flux, (2) can refraction induce premature axion-photon de-phasing, (3) what is the expected width of the line, (4) does the flux have a strong time-dependence, and (5) can these radio photons be efficiently absorbed.
Speaker: Samuel Witte (GRAPPA Institute, Univ Amsterdam) -
17:40
Constraints on Axion-like Particles from a Hard X-ray Observation of Betelgeuse 15m
Axion-like particles (ALPs) can be produced in stellar plasmas via the Primakoff process due to the photon-ALP coupling. Light ALPs produced in this way can easily escape the star and reconvert back into photons in the Galactic magnetic field. Betelgeuse (α-Orionis, spectral type M2Iab), a nearby red supergiant star, provides an excellent laboratory for ALP searches, as it (i) has a hot core, and thus is potentially a copious producer of ALPs that, after re-conversion, produces a photon signal peaked in the hard X-ray (E>10 keV) range, (ii) is in region of Hertzsprung-Russel diagram where no stable corona is expected, and thus has essentially zero standard astrophysical X-ray background, and (iii) is nearby, at a distance d~200 pc, and thus in a region of the local magnetic field that is relatively easier to constrain with future observations.
We use the first observation of Betelgeuse in hard X-rays to perform a novel search for ALPs. With a 50 ks observation by the NuSTAR satellite telescope, we find no significant excess of events above the expected background and set a stringent upper limit on the ALP-photon coupling. In this contribution, I will detail this work while focusing on the data analysis, results and impact, and emphasizing the uncertainty introduced by the stellar evolution model and the Galactic magnetic field.Speaker: Mengjiao Xiao (MIT) -
17:45
A Novel Search Technique for Ultralight Dark Matter Using Green Bank Telescope Data 15m
Most of the matter in the universe is widely thought to be non-baryonic and composed of unknown subatomic particles referred to as dark matter. While significant attention has been paid to a few specific candidates such as the WIMP and axion, in fact the nature and mass of dark matter is poorly constrained, and thus a broad observational approach may yield useful clues for its ultimate detection. We have developed a novel approach which utilizes the recent Breakthrough Listen public data release of three years of observation with the Green Bank Telescope to execute a broad search for an axion signal across billions of independent frequency channels simultaneously. This method is model-independent and only assumes that there is a decay or annihilation of virialized dark matter leading to a quasi-monochromatic radio line, and additionally that the line exhibits a Doppler shift with position according to the solar motion through a static galactic halo. This approach has been tested on a subset of L-band data, and the analysis of the full L-, S-, C- and X-band dataset (25,000 spectra, 1.1–11.6 GHz) is currently underway. This work was supported by a grant from the Heising-Simons Foundation.
Speaker: Aya Keller (UC Berkeley) -
17:45
Beyond the Standard Model Searches with the MAJORANA DEMONSTRATOR Experiment 15m
The MAJORANA DEMONSTRATOR experiment operated two modular arrays of p-type point contact high purity germanium (HPGe) detectors, of which 30 kg is enriched to 88% in Ge-76, to search for neutrinoless double beta decay. The data-taking campaign for double beta decay with enriched detectors was successfully concluded in March 2021, and data-taking with natural detectors is still ongoing. The DEMONSTRATOR has achieved excellent energy performance in a wide dynamic range covering 1 keV to 10 MeV. The extra-low background level and excellent energy performance achieved by the DEMONSTRATOR makes it competitive in various searches of physics beyond the Standard Model.
If there is an axion-photon coupling, axions can be produced by the Primakoff conversion of photons in the Sun. Solar axions can inversely generate photon signals in germanium crystals, which can be coherently enhanced when the Bragg condition is satisfied. The DEMONSTRATOR is searching for solar axions with a novel method to correlate and leverage its high number of HPGe detectors. In this talk, we will discuss the status and results of recent searches for new physics with the DEMONSTRATOR, including the first reporting of a solar axion search.
Speaker: Wenqin Xu (University of South Dakota) -
17:45
Constraining the diffuse supernova axion-like-particle background with high-latitude Fermi-LAT data 15m
Core-collapse supernovae (SNe) have been identified as a promising target to probe the existence of axion-like-particles (ALPs). The cumulative signal from all past SNe events would contain an ALP component and create a diffuse flux with energies $\mathcal{O}(50)$ MeV. We update the calculation of this flux by including SNe with different masses following the expected mass distribution, instead of using the spectrum obtained by using a single reference mass. Due to their coupling to photons and the related Primakoff process, the diffuse SNe ALP flux is converted into a diffuse gamma-ray flux while traversing the magnetic field of the Milky Way. The spatial morphology of this signal is expected to follow the shape of the Galactic magnetic field lines.
We perform a template-based analysis to constrain the ALP parameter space via the spatial structure of this ALP-induced diffuse gamma-ray flux using Fermi-LAT data from 12 years and an energy range from 50 MeV to 500 GeV. We find an improvement of the upper limit on the ALP-photon coupling constant $g_{a\gamma}$ about an order of magnitude compared to a previous analysis solely based on the spectral shape of the signal. Our results are robust against variations in the modelling of high-latitude Galactic diffuse emission and systematic uncertainties of the LAT.Speaker: Christopher Eckner (CNRS/LAPTh) -
17:45
First observation and analysis of DANCE: Dark matter Axion search with riNg Cavity Experiment 15m
Dark matter Axion search with riNg Cavity Experiment (DANCE) was proposed. To search for axion-like dark matter, we aim to detect the rotation and oscillation of optical linear polarization caused by axion-photon coupling with a bow-tie ring cavity. DANCE can improve the sensitivity to the axion-photon coupling constant for axion mass $< 10^{-10}$ eV by several orders of magnitude compared to the best upper limits at present. A prototype experiment DANCE Act-1 with a shorter cavity round-trip length of 1 m is ongoing to demonstrate the feasibility of our method and to investigate possible technical noises. We assembled the optics, evaluated the performance of the cavity. The first 12-day observation was successfully performed in May 2021, and the data analysis is underway. In this conference, we will report the principle of DANCE and the status of DANCE Act-1.
Speaker: Yuka Oshima (Department of Physics, University of Tokyo) -
17:45
MADMAX: A QCD Dark Matter Axion Direct-Detection Experiment 15m
Axions emerge naturally from the Peccei-Quinn (PQ) mechanism which addresses the absence of CP violation in the strong interaction, and they can make up the cold dark matter in the universe. If PQ symmetry breaking had occurred after inflation, the axion mass would likely range from ∼ 40 μeV to ∼ 1 meV, which is yet to be explored experimentally.
The MAgnetized Disc And Mirror Axion eXperiment is designed to reach sensitivity in the axion mass range of 40 to 400 µeV, a range inaccessible by previous axion experiments. This is reached by applying the dielectric haloscope approach, exploiting the axion to photon conversion at dielectric surfaces within a strong magnetic field. For MADMAX a system of movable dielectric discs inside an approximately 9 T magnetic field is foreseen.
The design, realization and timescale of MADMAX will be discussed along with prospects of the MADMAX prototype as well as first proofs of concept guiding the way towards the final experiment and the first physics run.
Speaker: Chang Lee (MPI for Physics) -
17:45
Searching For Axion Dark Matter with the South Pole Telescope 15m
Axions and other axion-like particles (ALPs) remain compelling dark matter candidates with a wealth of possible detection methods. A photon traveling through an axion field will experience a rotation in its polarization proportional to the difference in axion field value at photon emission and photon absorption. Thus the apparent polarization of a static astrophysical source will oscillate in time as the local axion dark matter field oscillates (with a frequency proportional to the axion mass). The cosmic microwave background (CMB) is polarized, well-studied, and extremely static, making it an ideal source with which to search for this effect. We present the status of such a search for ultra-light ALPs with masses roughly between $10^{-21}$ and $10^{-19}$ eV using data from the South Pole Telescope (SPT), a millimeter-band telescope with arcminute resolution that is located at the geographic South Pole and designed to observe the CMB.
Speaker: Kyle Ferguson (UCLA) -
17:45
Ultralight dark matter searches with KAGRA gravitational wave telescope 15m
Among various dark matter candidates, bosonic ultralight fields with masses below 1 eV are well motivated by cosmology because they behave as classical wave fields, rather than individual particles. Recently, a number of novel ideas have been proposed to search for ultralight dark matter candidates using laser interferometers at various scales. Those include our proposals to search for axion-like particles (ALPs) and vector fields with laser interferometric gravitational wave detectors. ALPs can be searched for by measuring the oscillating polarization rotation of laser beam. Massive vector field weakly coupled to the standard model sector can also be searched for by measuring the oscillating forces acting on the suspended mirrors of the interferometers. Within the KAGRA collaboration, the analysis of data from the KAGRA's observing run in 2020 to search for vector dark matter, and the installation of polarization optics to the arm cavity transmission ports of the interferometer to search for ALPs are underway. In this talk, we will report the status of such efforts to search for ultralight dark matter with KAGRA gravitational wave telescope.
Speaker: Yuta Michimura (Department of Physics, University of Tokyo) -
17:45
Using cryogenic Penning trap LC detection circuits to search for axion-like dark matter. 15m
We present recent limits set by the BASE collaboration on the coupling between any dark matter axion-like particles (ALPs) and photons, measured using the superconducting resonant single particle detection circuit of a cryogenic Penning trap. To search for ALPs, we investigated the noise spectrum of our fixed-frequency resonant circuit for peaks caused by axion-to-photon conversion in the strong magnetic field of the Penning trap magnet. Uniquely, we used a single antiproton interacting with our detection circuit to measure the detector noise temperature. Our analysis constrained the coupling of ALPs with masses around 2.7906-2.7914 neV/c$^{2}$ to photons to be $g_{a\gamma}< 1\times10^{-11}$ GeV$^{-1}$. We have recently begun to upgrade our ALP antenna to cover >2000 times broader mass range at improved sensitivity.
Speaker: Jack Devlin (CERN)
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Discussion Panel Dark Matter 5
Chair: Avelino Vicente
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17:10
Dark matter freeze-in from semi-production 15m
We study a novel dark matter production mechanism based on the freeze-in through semi-production, i.e. the inverse semi-annihilation processes. A peculiar feature of this scenario is that the production rate is suppressed by a small initial abundance of dark matter and consequently creating the observed abundance requires much larger coupling values than for the usual freeze-in. We provide a concrete example model exhibiting such production mechanism and study it in detail, extending the standard formalism to include the evolution of dark matter temperature alongside its number density and discuss the importance of this improved treatment. Finally, we confront the relic density constraint with the limits and prospects for the dark matter indirect detection searches. We show that, even if it was never in full thermal equilibrium in the early Universe, dark matter could, nevertheless, have strong enough present-day annihilation cross section to lead to observable signals.
Speaker: Maxim Laletin (NCBJ) -
17:10
Searching for pseudo-Nambu-Goldstone boson dark matter production in association with top quarks 15m
Pseudo-Nambu-Goldstone bosons (pNGBs) are attractive dark matter (DM) candidates since they are coupled to the Standard Model (SM) predominantly through derivative interactions. Thereby, they naturally evade the strong existing limits inferred from DM direct detection experiments. Working in an effective field theory that includes both derivative and non-derivative DM-SM operators, we perform a detailed phenomenological study of the Large Hadron Collider reach for pNGB DM production in association with top quarks. Drawing on motivated benchmark scenarios as examples, we compare our results to other collider limits as well as the constraints imposed by DM (in)direct detection experiments and the relic abundance. Furthermore, we explore implications on the viable parameter space of pNGB DM. In particular, we demonstrate that the sensitivity of DM direct detection experiments can be achieved via loop-induced interactions. The search strategies we discuss can serve as a starting point for dedicated experimental analyses by the ATLAS and CMS collaborations.
Speaker: Stefan Schulte (Max Planck Institute for Physics (Munich)) -
17:25
Supernova constraints on dark flavoured sectors 15m
I will present a recent application of the SN 1987A cooling bound to set a constraint on dark flavoured sectors. This is possible thanks to the fact that the protoneutron stars are hot and dense environments where hyperons can be efficiently produced. Therefore a decay of the form $Λ→nX^0$, where $X^0$ is a new bosonic dark particle, will be severely constrained. I will explain the ingredients required and the application to flavoured (massless) dark photons, axions and ALPs.
Speaker: Jorge Terol Calvo (Instituo de Astrofísica de Canarias (IAC)) -
17:40
Studying dark matter with MadDM: Lines and loops 15m
Automated tools for the computation of amplitudes and cross sections have become the backbone of phenomenological studies beyond the standard model. We present the latest developments in MadDM, a calculator of dark-matter observables based on MadGraph5_aMC@NLO. The new version enables the fully automated computation of loop-induced annihilation processes, relevant for indirect detection of dark matter. Of particular interest is the electroweak annihilation into $\gamma X$, where $X=\gamma$, $Z$, $h$ or any new unstable particle even under the dark symmetry. These processes lead to the sharp spectral feature of monochromatic gamma lines: a smoking-gun signature for dark matter annihilation in our Galaxy. MadDM provides the predictions for the respective fluxes near Earth and derives constraints from the gamma-ray line searches by Fermi-LAT and HESS. As an application, we present the implications for the parameter space of the Inert Doublet model and a top-philic $t$-channel mediator model.
Speaker: Daniele Massaro (Dipartimento di Fisica e Astronomia (DIFA), Alma Mater Studiorum - Università di Bologna; Centre for Cosmology, Particle Physics and Phenomenology (CP3), Université catholique de Louvain) -
17:45
Dark matter from a complex scalar singlet: The role of dark CP and other discrete symmetries 15m
In this talk I will study the case where dark matter emerges from a complex scalar field charged under a U(1) global symmetry, which is spontaneously broken. Our analysis considers different explicit symmetry breaking terms motivated by discrete symmetries. I will show results which demonstrate that in some regions of the parameter space these scenarios may be distinguished by combining different observables, such as direct detection and collider signatures. Finally we discuss the case where the stabilising symmetry may be broken, as well as an effective operator approach valid in the pseudo-Nambu-Goldstone limit.
Speaker: Carlos Faubel (IFIC (CSIC-Univ Valencia)) -
17:45
Dark matter in a charged variant of the Scotogenic model 15m
Scotogenic models are among the most popular possibilities to link dark matter
and neutrino masses. In this work we discuss a variant of the Scotogenic model
that includes charged fermions and a doublet with hypercharge 3/2. Neutrino
masses are induced at the one-loop level thanks to the states belonging to the dark sector. However, in contrast to the standard Scotogenic model, only the scalar dark matter candidate is viable in this version. After presenting the model and explaining some particularities about neutrino mass generation, we concentrate on its dark matter phenomenology. We show that the observed dark matter relic density can be correctly reproduced in the usual parameter space regions found for the standard Scotogenic model or the Inert Doublet model. In addition, the presence of the charged fermions may open up new regions, provided some tuning of the parameters is allowed.Speaker: Miguel Puerta (IFIC (CSIC-Univ Valencia)) -
17:45
Probing light dark scalars with future laboratory experiments 15m
We investigate a dark sector containing a pair of light non-degenerate scalar particles, with masses in the MeV-GeV range, coupled to the visibile sector through heavier mediators. The heaviest dark state is long-lived, and its decays offer new testable signals. We analyze the prospects for detection with the proposed beam-dump facility SHiP, and the proposed LHC experiments FASER and MATHUSLA. Moreover, we consider bounds from the beam-dump experiment CHARM and from colliders (LEP, LHC and BaBar). We present our results both in terms of an effective field theory, where the heavy mediators have been integrated out, and of a simplified model containing a vector boson mediator, which can be heavy O(1) TeV, or light O(10) GeV. We show that future experiments can test large portions of the parameter space currently unexplored, and that they are complementary to future High-Luminosity LHC searches.
Speaker: Marco Taoso (INFN Torino) -
17:45
The simplest scoto-seesaw model: WIMP dark matter phenomenology and Higgs vacuum stability 15m
We have examined the consistency of electroweak breaking, neutrino and dark matter phenomenology within the minimal scoto-seesaw mechanism. The model provides a simple picture where the ''atmospheric'' mass scale arises from the tree-level ''missing partner'' seesaw, while the ``solar'' scale is induced radiatively by the dark sector, hence neutrino mass generation is intimately connected with dark matter. The model can have both fermionic or scalar dark matter candidate. We have studied various prospects such as relic abundance, direct detection and indirect detection for scalar dark matter case. In addition we have studied the issue of vacuum stability and for this purpose we have derived the full two-loop RGEs for the relevant parameters, such as the quartic Higgs self-coupling $\lambda$ of the Standard Model. The new scalars present in the scoto-seesaw mechanism improve the stability properties of the electroweak vacuum. We have also explored the consistency of the underlying dark symmetry.
Speaker: Sanjoy Mandal (IFIC (CSIC-Univ Valencia)) -
17:45
Thermal WIMPs and the scale of new physics 15m
The non-observation of conclusive dark matter signals raises the question whether WIMPs can still account for the dark matter of the universe. In this talk I will present results from a global analysis of effective field theory operators describing the interactions between WIMPs and Standard Model particles. In this bottom-up approach, the global fitting framework GAMBIT is used to simultaneously vary the coefficients of 14 such operators, along with the WIMP mass, the scale of new physics and several nuisance parameters. The likelihood functions include the latest data from Planck, direct and indirect detection experiments, and the LHC. Although the observed relic density can be reproduced in large regions of parameter space, there cannot be a large hierarchy between the dark matter mass and the scale of new physics, which raises concerns about the validity of the effective field theory. I will discuss possible ways to address this issue in order to consistently interpret the latest results from WIMP searches at the LHC.
Speaker: Felix Kahlhoefer (RWTH Aachen University)
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Discussion Panel Gravitational Waves 1
Chair: Sukanta Bose
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Lunar Gravitational-Wave Antenna 15m
Gravitational waves excite quadrupolar vibrations of elastic bodies. Monitoring these vibrations was one of the first concepts proposed for the detection of gravitational waves by Joseph Weber. At laboratory scale, these experiments became known as resonant-bar detectors, which form an important part of the history of GW detection. Due to the dimensions of these bars, the targeted signal frequencies were in the kHz range. It was also Weber who suggested to monitor vibrations of the Moon to search for gravitational waves in the mHz band. His Lunar Surface Gravimeter was deployed on the Moon in 1972 by the Apollo 17 crew. A design error made it impossible to carry out the intended search for GWs, but the idea remains intriguing. We propose a Lunar Gravitational-Wave Antenna (LGWA) based on Weber’s idea. The key component is a next-generation, high-sensitivity seismometer to be deployed on the Moon. LGWA would have rich scientific synergies with other GW detectors like LISA and ET and also with EM observatories. At the same time, it would serve as a high-precision geophysical station shedding light on the interior structure of the Moon, the mechanisms of moonquakes, and the Moon's formation history. Furthermore, its technology is of high relevance for ET, and other future terrestrial GW detectors, as part of a new generation of seismic isolation systems.
Speaker: Jan Harms (Gran Sasso Science Institute) -
17:25
CSIS: a Cryogenic Superconducting Inertial Sensor 15m
The future of Gravitational Waves (GWs) is bright. LIGO and Virgo have detected more than 70 signals from black hole and/or neutron star mergers. All measured signals come in-band at around 30 Hz as suspension control noise, fueled by many cross couplings between angular and translational degrees of freedom, is dominant below 30 Hz. It is impossible to know, but exciting to imagine what signals are lurking there once we can access this regime.
Einstein Telescope (ET) will be an underground and cryogenic detector sensitive to GWs down to 2 Hz. New sensor development is underway for ET. We believe the cryogenic environment can be used in combination with superconducting materials to open up pathways to low-loss actuators and sensor mechanics.
The Cryogenic Superconducting Inertial Sensor (CSIS) revolutionizes the (cryogenic) inertial sensor field by obtaining a displacement sensitivity at 0.5 Hz of 3 orders of magnitude better than state-of-art. Not only will it help ET detect GWs from 2 Hz onwards, CSIS will also be deployed on the Moon. The recently published Lunar GW Antenna (LGWA) concept uses an inertial sensor to probe surface motion as a result of the GW excitation of the Moon's normal body modes (fundamental just below 1 mHz and many other modes and their harmonics at higher frequencies). In summary, CSIS will be the world's most sensitive low-frequency inertial sensor and, when deployed in ET and on the Moon, will enable GW science from 1 mHz to 10 Hz.
Speaker: Joris van Heijningen (UCLouvain) -
17:40
Bridging the microhertz gap with asteroids: opportunities and challenges for gravitational wave detection 15m
The science case for a broad program of gravitational wave (GW) detection across all frequency bands is exceptionally strong. At present, there is a dearth of coverage by existing and proposed searches in the GW frequency band lying between the peak sensitivities of PTAs and LISA, roughly 0.1-100 microhertz. In this talk, I will outline a conceptual mission proposal to access this band. I will demonstrate that a few carefully chosen asteroids which orbit in the inner Solar System can act as excellent naturally occurring gravitational test masses despite the environmental noise sources. As such, a GW detector can be constructed by ranging between these asteroids using optical or radio links. At low frequencies, I will discuss how gravity gradient noise arising from the combined motion of the other $\sim 10^6$ asteroids in the inner Solar System sharply cuts off the sensitivity of this proposal. Sensitivity in the middle of this band is mostly limited by various solar perturbations to the asteroid test masses, while the high-frequency sensitivity is limited by noise in the ranging link. The projected strain-sensitivity curve that I will present indicates significant potential reach in this frequency band for a mission of this type.
Speaker: Michael A. Fedderke (The Johns Hopkins University) -
17:45
Beyond the detector horizon: forecasting gravitational-wave strong lensing 15m
Gravitational waves could be gravitationally lensed just like light. Strong lensing makes gravitational waves appear as repeated events with different amplitudes within our detectors. We will investigate recent forecasts for observed lensed event rates, including sub-threshold searches. We will also discuss a pressing issue related to the current lensed event searches: the rising probability of so-called search false alarms. We show how the inclusion of lensing statistics can help remedy this problem.
Speaker: Renske Wierda (Utrecht University) -
17:45
Environmental noises in current and future gravitational-wave detectors. 15m
Gravitational-wave detectors are very sensitive instruments that suffer from a huge number of noises. If we aim to observe gravitational waves with Earth-based detectors, we need to take care of every source that can prevent the observation.
Seismic noise poses a huge challenge to the sensitivity in the the low frequency band and it is tackled with suspensions and active controls. The low frequency band can also be threatened by the so-called Newtonian noise, generated by the fluctuations of the gravity field. If this has not been a problem in the first generation gravitational-wave detectors, it will be so in the next runs and especially in the third-generation detectors, like the Einstein Telescope. We need then to be prepared to suppress as much as possible these noises, otherwise they might become the last wall for the sensitivity of our detectors.
This talk will explore environmental noises with a particular detail on Newtonian and seismic noise and the techniques that we can employ to reduce their effects.Speaker: Francesca Badaracco (UCLouvain) -
17:45
Estimations for the Newtonian noise of the future Einstein Telescope on the basis of data measured at Mátra Mountain Range in Hungary 15m
Seismic noise, the related gravitational gradient noise (Newtonian noise) and the thermal noise of the suspension last stage and of the test masses determine the sensitivity of current gravitational-wave detectors at low frequencies. Seismic and Newtonian noises can be mitigated by installing the detectors under the ground, while the thermal noise can be reduced by cryogenically cooling down the test masses. One of the proposed subterranean detectors, the European Einstein Telescope (ET) is planned to be built 200 to 300 m below the surface. The noise budget of ET at low frequencies is expected to be dominated by seismic noise and Newtonian noise of seismic and infrasonic origin. In order to get to know the long-term evolution of these types of noises, the Mátra Gravitational and Geophysical Laboratory (MGGL) was built 88 m below the surface at the Hungarian Mátra Mountain Range. Infrasound measurements and seismic noise measurements were started in 2017. The seismic noise measurements are still going on. We investigate the evolution of the Newtonian noise via applying the most recent modelling methods presented in literature and using our measurement data as input. I give an overview of the measurements done at MGGL, the modelling methods of Newtonian noise, and the results of our investigations.
Speaker: Edit Fenyvesi (Wigner Research Centre for Physics) -
17:45
Sub-threshold search for strongly lensed gravitational-wave events in the first half of LIGO-Virgo's third observing run 15m
Strong gravitational lensing of gravitational waves can produce duplicate signals separated in time with different amplitudes. We consider the case in which strong lensing produces identifiable gravitational wave events and weaker sub-threshold signals hidden in the noise background. We present a search method for the sub-threshold signals using targeted template banks targeting specific confirmed gravitational wave events. We apply the method to all the gravitational-wave signals from compact binary coalescences detected by Advanced LIGO and Advanced Virgo during O3a, the first half of their third observing run. Finally, we present the top 8 possible lensed candidates for O3a gravitational wave events that passed our nominal significance threshold of False Alarm Rate 1 in 16 years. Furthermore, we discuss the likelihood that these candidates are strongly lensed.
Speaker: Chan Chun Lung (The Chinese University of Hong Kong)
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Discussion Panel Neutrinos 3
Chair: Silvia Capelli
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17:10
Latest results from the CUORE experiment 15m
The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for 0νββ decay that has been able to reach the one-tonne mass scale. The detector, located at the LNGS in Italy, consists of an array of 988 TeO2 crystals arranged in a compact cylindrical structure of 19 towers. CUORE began its first physics data run in 2017 at a base temperature of about 10 mK and in April 2021 released its 3rd result of the search for 0νββ, corresponding to a tonne-year of TeO2 exposure. This is the largest amount of data ever acquired with a solid state detector and the most sensitive measurement of 0νββ decay in 130Te ever conducted, with a median exclusion sensitivity of 2.8×10^25 yr. We find no evidence of 0νββ decay and set a lower bound of 2.2 ×10^25 yr at a 90% credibility interval on the 130Te half-life for this process. In this talk, we present the current status of CUORE search for 0νββ with the updated statistics of one tonne-yr. We finally give an update of the CUORE background model and the measurement of the 130Te 2νββ decay half-life, study performed using an exposure of 300.7 kg⋅yr.
Speaker: Matteo Biassoni (INFN Milano Bicocca) -
17:25
Exposure-background duality in the searches of neutrinoless double beta decay 15m
Neutrinoless double-$\beta$ decay (0$\nu\beta\beta$) is an experimentally sensitive avenue to probe the nature (Majorana versus Dirac) and exact mass of neutrinos. This work [1] quantitatively explores the interplay between exposure and background levels in 0$\nu\beta\beta$ experiments at their design stage. In particular, background reduction will be playing increasingly important and investment-effective roles in future 0$\nu\beta\beta$ experiments. Although the primary goal of current running and projected experiments is to probe the inverted mass hierarchy, current neutrino oscillation experiments reveal a preference for non-degenerate (ND) normal mass hierarchy (NH). Therefore the strategy of scaling the summit of 0$\nu\beta\beta$ should also take this genuine possibility into account. Present work would explore the role of background suppression in alleviating the necessity of large exposure for future 0$\nu\beta\beta$ experiments with sensitivity goals of approaching and covering ND-NH. In particular, the roles of energy resolution in suppressing the irreducible background of 2$\nu\beta\beta$ will be discussed.
[1] M.K.Singh et al., Phys. Rev. D 101, 013006 (2020).
Speaker: Manoj Kumar Singh (Institute of Physics, Academia Sinica) -
17:40
Direct measurement of topological information using HUNI-ZICOS detector for 96Zr neutrinoless double beta decay experiment 15m
A liquid scintillator containing a tetrakis (isopropyl acetoacetato) zirconium (Zr(iPrac)$_{4}$) has been developed for ZICOS experiment which will search for neutrinoless double beta decay (0$\nu\beta\beta$) events using $^{96}$Zr isotope. The liquid scintillator has 10wt.% concentration of Zr(iPrac)$_{4}$, which corresponds to 1.4wt.% of natural zirconium.
In order to investigate a half-life of 0$\nu\beta\beta$ over 10$^{27}$ years, which corresponds to neutrino mass less than 0.01eV, we have to use tons scale of $^{96}$Zr isotope, and have to reduce 95% of backgrounds from $^{208}$Tl beta decay whose energy overlaps with the signal region.
For latter case, we have developed new technique to use Cherenkov light in order to reduce those backgrounds using the topology of location for photomultipliers received Cherenkov light, and have obtained that 93% of $^{208}$Tl decay events could be reduced with 78% efficiency for 0$\nu\beta\beta$ events. In order to realize this technique, we have developed the pulse shape discrimination to extract Cherenkov signal among scintillation, and have measured those topology using the hemisphere detector HUNI-ZICOS.
Here we report recent progress from those measurements, explain the status of demonstration of background reduction using UNI-ZICOS detector, and discuss about prototype ZICOS detector which will measure signal from 2$\nu\beta\beta$ as physics program.Speaker: Yoshiyuki Fukuda (Miyagi University of Education) -
18:10
Search for double beta decay of 106Cd with TGV-2 spectrometer 15m
Search for double beta decay processes (EC/EC, β+/EC, β+β+) of 106Cd was performed at the Modane underground laboratory (LSM, France, 4800 m w.e.) using the low-background multi–detector spectrometer TGV-2 and enriched 106Cd. The detector part of the TGV-2 is composed of 32 HPGe planar type detectors with the sensitive volume of 2040 mm2 x 6 mm each. The total sensitive volume of the detectors is about 400 cm3. TGV-2 detectors are arranged in 16 sandwich-like pairs of face-to-face detectors with 16 thin double beta emitters placed between them. The total mass of 16 investigated 106Cd foils (with an enrichment of 99.57% of 106Cd) have a total mass of ~23.2 g. The distance between the detectors and the emitters is < 1.5 mm. The 16 pairs are mounted one over another in a common cryostat tower. The energy resolution of the detectors ranged from 3.0 to 4.0 keV at 1332 keV (60Co). The total efficiency of the TGV-2 spectrometer is 50-70% depending on the energy threshold. The detector design delivers high detection efficiency for multiple coincidence events resulting in strong suppression of the background. The detector part of the TGV-2 spectrometer is surrounded by a copper shielding (> 20 cm), a steel airtight box against radon, a lead shielding (> 10 cm), and a neutron shielding made from borated polyethylene (16 cm).The TGV-2 spectrometer provides a high possibility of detection of double beta processes in 106Cd. Experiment started in February 2014. The preliminary results of data accumulated during 42500h will be presented with sensitivity level of T1/2 ~1×10^21 y at 90% C.L.
Speaker: Nikolay Rukhadze (Joint Institute for Nuclear Research) -
18:25
Barium Tagging for the NEXT Neutrinoless Double Beta Decay Program 15m
The NEXT collaboration is pursuing a phased program to search for neutrinoless double beta decay (0nubb) using high pressure xenon gas time projection chambers. The power of electroluminescent xenon gas TPCs for 0nubb derives from their excellent energy resolution (<1%FWHM), and the topological classification of two electron events, unique among scalable 0nubb technologies. Xenon gas detectors also also offer a further opportunity: the plausible implementation of single barium daughter ion tagging, an approach that may reduce radiogenic and cosmogenic backgrounds by orders of magnitude and unlock sensitivities that extend beyond the inverted neutrino mass ordering. In this talk I will present recent major advances in the development of single ion barium tagging for high pressure xenon gas detectors, as well as on detector concepts that may allow integration of single ion barium sensors within the time projection chambers of the NEXT program. Topics to be covered will include advances in single ion microscopy in high pressure gas, molecular sensor development including color-shifting and turn-on barium chemosensors, methods for concentrating ions to sensors and/or actuating sensors to ions, and plans for demonstrator phases that aim to prove barium tagging in-situ, on a 3-5 year timescale.
Speaker: Ben Jones (UTA) -
18:25
BINGO: Bi-Isotope 0ν2β Next Generation Observatory 15m
Neutrinoless double-beta decay (0ν2β) is a hypothetical rare nuclear transition. Its observation would provide an important insight about the nature of neutrinos (Dirac or Majorana particle) demonstrating that the lepton number is not conserved. BINGO aims to set the technological and conceptual grounds for future bolometric 0ν2β experiments. It is based on a dual heat-light readout, i.e. a main absorber embedding the double-beta decay isotope faced by a light detector. Dual heat-light readout helps to reject the α background component, thanks to the lower light output of α’s compared to β/γ’s. BINGO will study two of the most promising isotopes: 100Mo embedded in Li2MoO4 and 130Te embedded in TeO2. BINGO’s proposed technology aims at reducing dramatically the background in the region of interest, thus boosting the discovery sensitivity of 0νββ. This can be achieved by fulfilling the following goals: (i) increasing the light detector sensitivity thanks to Neganov-Luke amplification; (ii) having a revolutionary detector assembly that will reduce the total surface radioactivity contribution; (iii) using an active shield, based on ZnWO4 or BGO scintillators with bolometric readout, to suppress the external gamma background. The proposed solutions will have a high impact on next-generation bolometric tonne-scale experiments.
In this contribution we present the first results on the revolutionary assembly and on the bolometric veto.Speaker: Claudia Nones (IRFU/DPhP) -
18:25
CDEX-300ν: neutrinoless double beta decay experiment based on 76Ge 15m
Neutrinoless double beta decay has been a key topic that could help scientists to understand the properties of the neutrino including whether the neutrino is its own antiparticle, lepton number violation and so on. The China Dark Matter Experiment (CDEX) aims at direct searches of light Weakly Interacting Massive Particles (WIMPs) and neutrinoless double beta decay experiment at the China Jinping Underground Laboratory (CJPL) based on germanium detector array. From 2021 on, CDEX collaboration is pushing forward to setup a CDEX-300ν experiment based on 76Ge-enriched germanium array detector system to search neutrinoless double beta decays of 76Ge isotope. CDEX-300ν detector system will includes a 76Ge-enriched germanium array detector system with total mass of 300 kg and the germanium detectors are immersed into a liquid argon cooling and active shielding system with volume of ~8 m³. The liquid argon tank is located into a liquid nitrogen tank with a volume of 1725 m³ for cooling down and further decreasing the ambient radioactive backgrounds. More details of CDEX-300ν will be introduced in this talk.
Speaker: Qian Yue -
18:25
CUPID: a next generation bolometric neutrinoless double beta decay experiment 15m
CUPID is a next-generation tonne-scale bolometric neutrinoless double beta decay experiment to probe the Majorana nature of neutrinos and discover Lepton Number Violation if the effective neutrino mass is greater than 10 meV. CUPID will be built on experience, expertise and lessons learned in CUORE, and will be installed in the current CUORE infrastructure in the Gran Sasso underground laboratory. The CUPID detector technology, successfully tested in the CUPID-Mo experiment, is
based on scintillating bolometers of Li2MoO4 enriched in the isotope of interest 100Mo. In order to achieve its ambitious science goals, CUPID aims to reduce the backgrounds in the region of interest by a factor 100 with respect to CUORE. This performance will be achieved by introducing the high efficiently alpha/beta discrimination demonstrated by the
CUPID-0 and CUPID-Mo experiments, and using a high transition energy double beta decay nucleus such as 100Mo to minimize the impact of the gamma background. CUPID will consist of about 1500 hybrid heat-light detectors for a total isotope mass of 250 kg. The CUPID scientific reach is supported by a detailed and safe background model that uses CUORE, CUPID-Mo and CUPID-0 results. The required performance in terms of energy resolution, alpha rejection factor and crystal purity have already been demonstrated and will be presented.Speaker: Jonathan L. Ouellet (MIT) -
18:25
Gerda: Final Results and Physics Beyond Neutrinoless Double-Beta Decay 15m
The Gerda experiment searched for the lepton number violating neutrinoless double-beta (0νββ) decay of 76Ge. Observation of this decay would provide answers to fundamental problems in particle physics and cosmology, including the origin of neutrino masses and baryon asymmetry in the universe. The Gerda experiment achieved the most stringent lower limit on the half-life of the 0νββ-decay of 1.8 · 10^26 yr at 90% C.L. (which coincides with the sensitivity) by operating high-purity germanium (HPGe) detectors enriched in 76Ge submerged in liquid argon (LAr). The collaboration could achieve this breakthrough by reducing the background event rate to 5.2 · 10^−4 counts/(keV kg yr) at the end-point energy. This unprecedented background index could be achieved by developing unique technologies like utilizing the scintillation light of the LAr to reject efficiently background events that deposit energy simultaneously in the HPGe detectors and in LAr, and the pulse shape discrimination which exploits specific event topologies of backgrounds and signal candidates. Due to the ultra-low background approach the Gerda data is also suited for other rare event searches beyond the 0νββ decay like the search for super-WIMPs. This talk will present an overview of the Gerda experiment, its final results and prospects for other physics in the Gerda data.
Speaker: Patrick Krause (Technical University of Munich, INFN Roma Tre) -
18:25
KamLAND-Zen 800 Status and Progress with the Artificial Intelligence Powered Analysis 15m
The discovery of neutrinoless double beta decay (0νββ) would shed light on the persistent puzzle surrounding the origin of neutrino mass and help explain the matter-dominated universe. KamLAND-Zen is one of the leading experiments searching for 0νββ. The first phase of the experiment, called KamLAND-Zen 400, set a world-leading limit on 0νββ lifetime. After the conclusion of KamLAND-Zen 400, a brand new mini-balloon with a larger volume and cleaner surface were instrumented to contain 745 kg of Xe136. Since Jan. 2019, KamLAND-Zen 800 has started data-taking and aims to improve on the previous 0νββ result. A detailed study of the backgrounds in this new data will be presented along with a state-of-the-art approach for classifying backgrounds using a new algorithm called KamNet. The rejection power of KamNet does not rely on coincidence tagging and scales with hardware updates. With the help of KamNet, the 0νββ sensitivity of KamLAND-Zen 800 is significantly enhanced to a new summit.
Speaker: Aobo Li (UNC Chapel Hill) -
18:25
Latest results of the R2D2 project towards a possible future neutrino double beta decay experiment 15m
The search for neutrinoless double beta decay could cast light on one critical piece missing in our knowledge i.e. the nature of the neutrino mass. Its observation is indeed the most sensitive experimental way to prove that neutrino is a Majorana particle. The observation of such a potentially rare process demands a detector with an excellent energy resolution, an extremely low radioactivity and a large mass of emitter isotope. Nowadays many techniques are pursued but none of them meets all the requirements at the same time. The goal of R2D2 is to prove that a spherical high pressure TPC could meet all the requirements and provide an ideal detector for the 0νββ decay search. The prototype has demonstrated an excellent resolution with Argon and the preliminary results with Xenon are already very promising. In the proposed talk the R2D2 results obtained with the first prototype will be discussed as well as the project roadmap and future developments.
Speaker: Ioannis Katsioulas (University of Birmingham) -
18:25
Light only Liquid Xenon (LoLX) experiment 15m
The Light only Liquid Xenon (LoLX) experiment was designed to study light production in liquid xenon during the first nanosecond and gain experience with the operation of a large number of closely spaced Silicon Photomultipliers (SiPMs) in liquid xenon. The LoLX detector is a 3D printed octagonal chamber housing 96 Hamamatsu VUV4 SiPMs, 16 on top and bottom and 8 on each side of the octagon. A β-source Sr-90 is inserted in the middle of the chamber. Most (88) SiPMs are covered by long pass filters preventing transmission of light below 225nm, and are to be used for isolating the Cerenkov light. 4 SiPMs are uncovered and 4 are covered by a band pass filter centered at the xenon scintillation wavelength. Results will be presented including a measure of the beta decays with the combined scintillation and Cerenkov channels. The focus of the current phase of the experiment is to demonstrate spectral separation of Cerenkov and scintillation which is a prerequisite for studying scintillation during the first ns. LoLX will be upgraded in 2021 to achieve about 100ps timing resolution as opposed to about 1ns currently achieved. Eventually digital SiPMs will be used in an attempt to reach 10ps single photon timing resolution. The LoLX results will also include a study of SiPM external cross-talk, where photons produced by a charge avalanche in a SiPM trigger an avalanche in another. The unique shape of the chamber offers opportunity to study external crosstalk at varying angles and distances. Not only will LoLX results help predict the performances of the nEXO experiment but also determine if early light measurement carry valuable information for better timing and possibly energy resolutions, to improve particle identification.
Speaker: Liang Xie (TRIUMF) -
18:25
Measurement of the 136Xe two-neutrino double beta decay half-life with NEXT-White 15m
The NEXT (Neutrino Experiment with a Xenon TPC) collaboration searches for the neutrino-less double beta decay (ββ0ν) of 136Xe at the Laboratorio Subterráneo de Canfranc (LSC) (Huesca, Spain). The observation of such a lepton-number-violation process would prove the Majorana nature of neutrinos, providing also information on the neutrino mass scale. A first large-scale prototype of a high-pressure Xenon gas electroluminescent TPC, NEXT-White, is being operated at the LSC since 2016. This 5-kg radiopure detector has already proven an outstanding performance of the NEXT technology in terms of the energy resolution (<1% FWHM at 2.6 MeV) as well as a tracking-based background rejection. NEXT-White has also measured the relevant backgrounds for the ββ0ν search using both 136Xe-depleted and 136Xe-enriched xenon. In this talk, the measurement of the half-life of the two-neutrino mode of the double beta decay (ββ2ν) will be presented. For this measurement, two novel techniques in the field have been used: 1) an iterative deconvolution algorithm that allows a highly refined reconstruction of the single and double electron tracks, improving the background rejection, and 2) a direct subtraction of the ββ backgrounds, measured with 136Xe-depleted data. These techniques allow for background-model-dependent and background-model-independent results, demonstrating the robustness of the ββ2ν half-life measurement and the unique capabilities of NEXT. The physics program of NEXT-White will be completed in late 2021, when the construction of the NEXT-100 detector at the LSC starts. Holding 100 kg of 136Xe and with a background index below 5×10−4 counts/keV/kg/year, this detector will perform the first competitive ββ0ν search within the NEXT roadmap. As validated with NEXT-White, NEXT-100 will reach a sensitivity to the half-life of 6×10^25 y after 3 years of data taking.
Speaker: Alberto Usón (IFIC (CSIC-Univ Valencia)) -
18:25
New Results from the CUPID-Mo demonstrator on the 100Mo 0νββ decay half-life 15m
CUPID-Mo served as a successful demonstrator experiment for CUPID (CUORE Upgrade with Particle ID), the planned next-generation upgrade of the first ton scale cryogenic calorimetric $0\nu\beta\beta$ decay experiment, CUORE (Cryogenic Underground Observatory for Rare Events). CUPID-Mo was operated at Laboratoire Souterrain de Modane in France as an array of 20 enriched Li$_{2}$$^{100}$MoO$_{4}$ (LMO) cylindrical scintillating crystals ($\sim$200g each) each featuring a Ge light detector (LD) all at $\sim$20 mK. The LMOs and LDs were instrumented with NTD thermistors allowing for the collection of both heat and scintillation light. This dual mode of energy collection allows for $\alpha$ events to be distinguished from $\beta$/$\gamma$ events, significantly reducing the background from degraded $\alpha$s in the heat channel. CUPID-Mo has a demonstrated energy resolution of $\sim$7 keV (FWHM) at 2615 keV, complete $\alpha$/$(\beta$/$\gamma)$ discrimination and very low radioactive contamination. Here we report the results of an analysis of the full CUPID-Mo exposure, detailing improved analysis techniques and present an updated limit on the $0\nu\beta\beta$ decay half-life for $^{100}$Mo. We also will describe the status of other ongoing analysis efforts underway with the CUPID-Mo dataset.
Speaker: Bradford Welliver (LBNL) -
18:25
nEXO: Search for Neutrino-less Double Beta Decay at the Tonne Scale 15m
nEXO is a 5 tonne monolithic liquid xenon (LXe) time projection chamber (TPC) planned to search for the neutrinoless double beta decay of $^{136}$Xe with an estimated half-life sensitivity of $> 10^{28}$ years at 90% C.L.. Advancements were made in terms of detector design, signal modelling and data analysis to support a refined estimate of the sensitivity and discovery potential of the nEXO experiment. In particular, we updated the detector geometry in line with most recent advancements in our engineering design, we implemented a more realistic and data-driven modelling of the light and charge channel signals and developed a Deep Neutral Network based analysis to discriminate between signal and background. This talk will cover the simulation, reconstruction and the physics reach of nEXO.
Speaker: Ako Jamil (Yale University) -
18:25
Prospects of neutrinoless double beta decay search with PandaX-4T and beyond 15m
Large liquid xenon Time Projection Chambers (TPC) with multi-ton of active mass, such as PandaX-4T, have hundreds of kilogram of Xe-136 and can be used to search for neutrinoless double beta decay (NLDBD). PandaX-4T is taking commissioning data as for now at China JinPing Underground Laboratory (CJPL). We will present the detector performance at high energy and the physics potential to search for NLDBD. Next generation of xenon TPC with even larger target may reach the inverted mass hierarchy of effective Majorana neutrino mass.
Speaker: Ke Han (Shanghai Jiao Tong University) -
18:25
SNO+ 15m
SNO+ is a multi-purpose neutrino experiment located at SNOLAB. Now filled with liquid scintillator after a challenging campaign of operations during the pandemic, SNO+ is studying backgrounds in the detector and embarking on a neutrino physics program including reactor, geo and solar neutrinos. The ultimate goal of SNO+ is to deploy roughly 4 tonnes of tellurium (0.5%) in the scintillator to conduct a neutrinoless double beta decay search. This talk will present the prospects and a preliminary look at data from SNO+.
Speaker: Mark Chen (Queen's University) -
18:25
Status of 48Ca double beta decay search in CANDLES 15m
The origin of neutrino masses is one of the unsolved puzzles in particle physics. One possibility is that neutrinos have Majorana masses.We can test the Majorana nature of neutrinos by searching for neutrinoless double-beta decay ($0\nu\beta\beta$) events.CANDLE is a project which targets $0\nu\beta\beta$ events from ${}^{48}$Ca using its high Q$_{\beta\beta}$-value of $4.27\,$MeV. We developed a CANDLES-III system with 96 $\mathrm{CaF}_2$ scintillation crystals with natural Ca isotope, which corresponds to $350\,$g of ${}^{48}$Ca.The key to search for $0\nu\beta\beta$ with the CANDLES-III is to identify and remove the $\beta$ decay background events from impurities in $\mathrm{CaF}_2$ crystals. Especially, $\beta$ decay events from ${}^{208}$Tl with Q$_{\beta}$-value of $5.0\,$MeV are dominant background events.
In the proposed talk, an improved sensitivity by a new ${}^{208}$Tl background removal method and the latest results of the search for $0\nu\beta\beta$ will be discussed.Speaker: Yuto Minami (RCNP, Osaka Univ.) -
18:25
Status of AMoRE 15m
AMoRE is a search for neutrinoless double beta decay using Mo-100 enriched crystal scintillators at an ultra-low temperature. We have understood the major background sources and how they can be reduced from a pilot stage run in the Yangyang underground laboratory. AMoRE-I is currently running with twelve $^{48\textrm{depl}}$Ca$^{100}$MoO$_{4}$ and five Li$_{2}^{100}$MoO$_{4}$ crystals with a total mass of enriched $^{100}$Mo 2.8 kg. The detector design for the main stage of the experiment, AMoRE-II, has been finalized and the detector is under construction in YemiLab, a new underground laboratory located in an iron mine with an average depth 2500 meter of water equivalent. The status of AMoRE-I and the preparations for AMoRE-II will be presented.
Speaker: Yoomin Oh (Center for Underground Physics, Institute for Basic Science) -
18:25
Tests of the Lorentz invariance violation in double-beta decay 15m
There is currently interest in testing possible Lorentz invariance violation (LIV) in different physical processes. LIV effects have also been searched in the neutrino sector, mainly in neutrino oscillation experiments. However, there are LIV effects induced by a Lorentz-violating operator in the Standard Model extension (SME) theory, called countershaded operator, which does not affect the neutrino oscillations. Such effects, related to the time-like component of this operator, which are controlled by the oscillation-free (of) coefficient (aof3)00, would produce small deviations in the
shape of the energy spectra of electrons emitted in double-beta decays. Such investigations are currently been conducted in several double beta decay experiments as EXO, GERDA, SuperNEMO, CUORE and CUPID-0. These analysis are based on accurate theoretical predictions of the electron spectra and their angular correlations in 2νββ decay.
In my talk I will give a current review of this topic. I will first present the precise calculation of the summed energy electron spectra and their deviations due to LIV, and the constraints of the (aof3)00 coefficient obtained from these analyzes. Next, I show that current investigations of LIV can be complemented by searches in the single electron spectra and angular correlations between the emitted electrons. Distortions due to LIV occur in the single electron spectra (maximal at small electron energies) and other effects may be highlighted by analyzing the angular correlation spectra and the ratio between the SME electron spectra and their SM forms. Finally, I will present an
alternative, new method to constrain (aof3)00 through the measurement of the angular correlation coefficient, and show that future experiments can improve these limits significantly.References
1. S. Stoica, Investigation of Lorentz symmetry violation in double-beta decay, MEDEX’19, Prague, May 28-June 2, 2019 (invited lecture).
2. O. Nitescu, S. Ghinescu, and S. Stoica, J. Phys. G 47, 055112 (2020).
3. O. Nitescu, S. Ghinescu, and S. Stoica, Phys. Rev. D 103, L031701 (2021).
4. S. Stoica, Study of kinematic factors in double-beta decay, Conference on Neutrino and Nuclear Physics (CNNP2020), February 20-24, Cape Town, South Africa (invited lecture).Speaker: Sabin Stoica (International Centre for Advanced Training and Research in Physics (CIFRA)) -
18:25
The LEGEND program - search for neutrinoless double beta decay in Ge-76 15m
The Large Enriched Germanium Experiment for Neutrinoless $\beta\beta$ Decay (LEGEND) is a phased experimental effort to search for neutrinoless double-beta decay in $^{76}$Ge. The first phase uses existing resources building off the experiences of the Majorana and GERDA experiments, as well as new techniques like larger inverted coaxial detectors and an improved Argon detector system. It consists of 200 kg of $^{76}$Ge enriched germanium, and assembly and testing of components has begun. The collaboration is planning to start commissioning in the second half of this year. I will give an overview on the status of the effort and also on its proposed successor, LEGEND-1000. My presentation will also cover LEGENDs physics reach, its design, its ongoing R\&D, and further efforts that are necessary to deploy an experiment with an half-life discovery potential of beyond 10$^{28}$ years half-life for neutrinoless double beta decay.
*This work is supported by the U.S. DOE, and the NSF, the LANL, ORNL and LBNL LDRD programs; the European ERC and Horizon programs; the German DFG, BMBF, and MPG; the Italian INFN; the Polish NCN and MNiSW; the Czech MEYS; the Slovak SRDA; the Swiss SNF; the UK STFC; the Russian RFBR; the Canadian NSERC and CFI; the LNGS and SURF facilities.
LA-UR-21-26052Speaker: Ralph Massarczyk (Los Alamos National Laboratory) -
18:25
The MAJORANA DEMONSTRATOR's Search for Neutrinoless Double-Beta Decay 15m
The MAJORANA DEMONSTRATOR has recently completed data-taking for its search for neutrinoless double-beta decay ($0\nu\beta\beta$) in $^{76}$Ge.
If observed, this beyond the standard model process that would prove the neutrino is a Majorana fermion and provide a path to leptogenesis in the early universe.
The experiment has completed operation of a modular array of 44 kg of high purity germanium detectors, in the p-type point contact (PPC), inverted-coaxial point-contact (ICPC), and broad energy germanium (BEGe) geometries.
30 kg of PPC and 6 kg of ICPC detectors belonging to the LEGEND experiment were enriched to 88% in $^{76}$Ge.
After removing the enriched detectors in March of 2021 for future operation in LEGEND-200, the experiment is continuing to operate 23 BEGe detectors with natural isotopic abundance.
To minimize backgrounds, the DEMONSTRATOR is constructed from low-background materials and housed inside a compact shield consisting of lead and copper at the Sanford Underground Research Facility (SURF) in Lead, SD.
Each of the detector geometries enable the use of pulse shape discrimination techniques that can reject multi-site and surface backgrounds.
Furthermore, the experiment has achieved a leading energy resolution of 0.12% FWHM at 2039 keV.
This talk will provide an update on recent improvements to the MAJORANA analysis and future plans for the experiment.This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics and Nuclear Physics Programs of the National Science Foundation, and the Sanford Underground Research Facility.
Speaker: Julieta Gruszko (Univ North Carolina) -
18:25
The neutrinoless double beta decay CROSS experiment: demonstrator with surface sensitive bolometers 15m
Nowadays, double beta decay searches are an important point of interest in neutrino physics: the observation of neutrinoless double beta (0$\nu$2$\beta$) decay will give essential information on neutrino masses and nature as well as on lepton number violation. The technological challenge for highly sensitive 0$\nu$2$\beta$ experiments includes the minimization of the background index in the region of interest. The key feature of CROSS (Cryogenic Rare-event Observatory with Surface Sensitivity) is the active surface background rejection using bolometric detectors coated with thin metallic films. Such a film on the detector surface affects the conversion of the energy deposited by the particle interaction. The phonon reabsorbtion in the film leads to a modification of the pulse shape for close-to-film events. With single-channel separation of surface $\alpha$ and $\beta$ particles, the CROSS technology can be used for next-generation bolometric experiments, reaching a background index in the region of interest of $\sim$10$^{-5}$ counts/(keV$\times$kg$\times$y).
Several series of reduced-scale prototypes with coated Li$_2$MoO$_4$ and TeO$_2$ crystals (isotopes of interest for 0$\nu$2$\beta$ are $^{100}$Mo and $^{130}$Te) were studied in an aboveground cryostat at IJCLab, Orsay.
Successful observation of surface alpha and beta separation with Pd-Al grids was performed, and first full-size (45x45x45 mm, $\sim$280 g) prototypes based on a Li$_2$$^{100}$MoO$_4$ crystal for the CROSS demonstrator were assembled.The surface-event identification can be combined with alpha particle rejection achievable in scintillating bolometers, providing a powerful redundancy for background mitigation. In this framework, the underground cryogenic facility of CROSS (Canfranc Underground laboratory) hosted several arrays of Li$_2$$^{100}$MoO$_4$ scintillating bolometers (in collaboration with CUPID experiment) to perform studies of detectors performance and reproducibility. Several options for light collection optimization were investigated, with light yields ranging from $\sim$0.2 to $\sim$0.6 keV/MeV. These results are used for the optimization of the detector modules both for the CUPID experiment and the CROSS demonstrator, which will consist of an array of about 60 crystals of Li$_2$MoO$_4$ containing 6.6 kg of $^{100}$Mo featuring both light-yield and pulse-shape discrimination capabilities. The 2 year sensitivity of the CROSS demonstrator is 2$\times$10$^{25}$ years, corresponding to effective neutrino mass bounds of 86 - 149 meV.
Speaker: Anastasiia Zolotarova (CNRS/IJCLab) -
18:25
The ultimate limit on 82Se neutrinoless double-beta decay search with CUPID-0 15m
CUPID-0 is the first pilot experiment of CUPID, a next-generation project to search for neutrinoless double beta decay (0νDBD) with scintillating bolometers.
The detector, consisting of 24 enriched and 2 natural ZnSe crystals, has been taking data at Laboratori Nazionali del Gran Sasso from March 2017 to December 2018 (Phase I) and from May 2019 to February 2020 (Phase II), for a total exposure of 16.59 kg yr of ZnSe.
In this contribution, we present the new combined results of Phase-I and Phase II in the search for Se-82 0νDBD, both to the ground state and to the excited states of Kr-82.
The successful operation of the CUPID-0 detector demonstrates that scintillating calorimeters allow us to reach the lowest background for calorimetric experiments: (3.5+1.0−0.9)×10−3 counts/(keV kg yr).
We reach a 90% credible interval median sensitivity of $0.7~\times~10^{25}$ yr and set the most stringent limit on the half-life of Se-82 0vDBD, $T_{1/2}^{0\nu} > 4.7~\times~10^{24}$ yr (90% credible interval), corresponding to $m_{\beta\beta} < (276 - 570)$ meV depending on the nuclear matrix element calculations.
The CUPID-0 result surpasses the sensitivity foreseen for scheduled Se82-based experiments, and it is therefore a candidate to be the best result on the Se-82 for a long time.Speaker: Lorenzo Pagnanini (INFN - LNGS & GSSI)
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Discussion Panel Neutrinos 4
Chair: Georgia Karagiorgi
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Reactor antineutrino anomaly in light of recent flux model refinements 15m
We study the status of the reactor antineutrino anomaly in light of new reactor flux models from both conversion and summation methods. We find that both the reactor rate and fuel evolution data are consistent with the predictions both from the conversion model of Kopeikin et al. and the summation model of Estienne et al. The convergence of both model predictions indicates the rebustness for the solution to the reactor anomaly in terms of flux model refinements.
Speaker: Zhao Xin -
17:25
Status of the Short-Baseline Near Detector at Fermilab 15m
The Short-Baseline Near Detector (SBND) will be one of three liquid Argon Time Projection Chamber (LArTPC) neutrino detectors positioned along the axis of the Booster Neutrino Beam (BNB) at Fermilab, as part of the Short-Baseline Neutrino (SBN) Program. The detector is currently in the construction phase and is anticipated to begin operation in the second half of 2022. SBND is characterised by superb imaging capabilities and will record over a million neutrino interactions per year. Thanks to its unique combination of measurement resolution and statistics, SBND will carry out a rich program of neutrino interaction measurements and novel searches for physics beyond the Standard Model (BSM). It will enable the potential of the overall SBN sterile neutrino program by performing a precise characterisation of the unoscillated event rate, and by constraining BNB flux and neutrino-Argon cross-section systematic uncertainties. In this talk, the physics reach, current status, and future prospects of SBND are discussed.
Speaker: José I. Crespo-Anadón (CIEMAT) -
17:45
A lab-scale experiment for keV sterile neutrino search from tritium beta decay spectrum 15m
We developed a simple small-scale detection method for beta decay
spectrum of 3H. This research is motivated to investigate the presence
of sterile neutrinos in keV region. In our experiment, tritium nuclei
are embedded in a 1x1x1 cm^3 LiF crystal from 6Li(n,3H)4He reaction.
The beta energy spectrum is measured with an MMC sensor, one of the
high-resolution microcalorimeters operating at mK temperatures. We
present the method for the sample preparation and the experiment
together with the physics result from the first measurement set.
Moreover, an expected sensitivity to search for the heavy neutrino is
discussed for one year measurement with the setup.Speaker: YongChang Lee (IBS, SNU) -
17:45
Antineutrino spectrometer DANSS - 5 years of running 15m
Solid scintillator reactor antineutrino detector DANSS is placed on a
movable platform below 3.1 GW industrial reactor of the Kalininskaya Nuclear
Power Plant. The distance between the detector and the center of
the reactor core is frequently changed in the range 10.9 - 12.9 m. The
reactor materials provide overburden of about 50 m.w.e.
The one-cubic-meter sensitive volume of the detector is assembled
from 2500 polystyrene scintillation strips and surrounded
by a multilayer passive and active shielding. A dual readout
by silicon photo multipliers (individually) and by convention PMTs
(in groups of 50 strips) is used to achieve both high detector
granularity and low noise trigger.In the position closest to the reactor core up to 5000 inverse
beta-decay events per day are collected with cosmic muons induced
background below 2%. The talk covers 5 years of the detector operation,
results of our search for light sterile neutrinos as well as plans for
the detector upgrade.Speaker: Igor Alekseev (ITEP) -
17:45
PROSPECT's Latest Results 15m
The Precision Reactor Oscillation and SPECTrum experiment, PROSPECT, is a reactor antineutrino experiment located at the High Flux Isotope Reactor (HFIR). The detector is deployed on surface with minimal overburden at very short baseline from the highly enriched uranium reactor core. With this configuration, PROSPECT detector can be used to explore different variety of physics topics, from reactor to BSM physics.
This talk will summarize PROSPECT’s latest results, including recent sterile neutrino oscillation analyses, measurement of the $^{235}$U antineutrino spectrum, and a dedicated search for boosted sub-GeV dark matter. It will also discuss future plans to perform improved physics measurements with a second-generation detector, called PROSPECT-II.
Speaker: Manoa Andriamirado (Illinois Institute of Technology) -
17:45
Searching for non-unitary neutrino oscillations in the present T2K and NO$\nu$A data 15m
The mixing of three active neutrino flavors is parameterized by the unitary PMNS matrix. If there are more than three neutrino flavors and if the extra generations are heavy iso-singlets, the effective $3\times 3$ mixing matrix for the three active neutrinos will be non-unitary. We have analyzed the latest T2K and NO$\nu$A data with the hypothesis of non-unitary mixing of the active neutrinos. We found that the 2019 NO$\nu$A data slightly (at $\sim 1\, \sigma$ C.L.) prefer the non-unitary mixing over unitary mixing. In fact, allowing the non-unitary mixing brings the NO$\nu$A best-fit point in the $\sin^2\theta_{23}-\delta_{\rm CP}$ plane closer to the T2K best-fit point. The 2019 T2K data, on the other hand, cannot rule out any of the two mixing schemes. A combined analysis of the NO$\nu$A and T2K 2019 data prefers the non-unitary mixing at $1\, \sigma$ C.L.. We derive constraints on the non-unitary mixing parameters using the best-fit to the combined NO$\nu$A and T2K data. These constraints are weaker than previously found. The latest 2020 data from both the experiments prefer non-unitarity over unitary mixing at $1\, \sigma$ C.L. The combined analysis prefers non-unitarity at $2\, \sigma$ C.L. The stronger tension, which exists between the latest 2020 data of the two experiments, also gets reduced with non-unitary analysis.
Speaker: Ushak Rahaman (University of Johannesburg) -
17:45
Separation of the U-235 and Pu-239 Prompt Energy Spectra in NEOS-II 15m
The NEOS aims to search for sterile neutrinos by detecting reactor antineutrinos at a very short baseline in Korea. The NEOS detector (1 ton GdLS) is deployed at the tendon gallery of the Hanbit reactor unit 5 (2.8 GW thermal power), 24 m away from the reactor core. In NEOS-I, the prompt energy spectrum from inverse-beta-decay was measured using 180 days of reactor-on data, where the "5 MeV excess" was clearly observed. To understand the origin of the "5 MeV excess", NEOS-II has taken 500 (60) days of reactor-on(-off) data from September 2018 to October 2020, covering a whole burnup cycle of the reactor. In this talk, we present a preliminary result on the extraction of the U-235 and Pu-239 prompt energy spectra for the whole burnup cycle, which may shed light on the origin of the "5MeV excess".
Speaker: Jinyu Kim (Institute for Basic Science, Sejong University) -
17:45
Short-Baseline neutrino oscillation searches with the ICARUS detector 15m
The ICARUS collaboration employed the 760-ton T600 detector in a successful three-year physics run at the underground LNGS laboratories studying neutrino oscillations with the CNGS neutrino beam from CERN, and searching for atmospheric neutrino interactions. ICARUS performed a sensitive search for LSND-like anomalous νe appearance in the CNGS beam, which contributed to the constraints on the allowed parameters to a narrow region around 1 eV$^2$, where all the experimental results can be coherently accommodated at 90% C.L. After a significant overhaul at CERN, the T600 detector has been installed at Fermilab. In 2020 cryogenic commissioning began with detector cool down, liquid Argon filling and recirculation. ICARUS has started operations and is presently in its commissioning phase, collecting the first neutrino events from the Booster Neutrino Beam and the NuMI off-axis. The main goal of the first year of ICARUS data taking will then be the definitive verification of the recent claim by NEUTRINO-4 short baseline reactor experiment both in the $\nu_\mu$ channel with the BNB and in the $\nu_e$ with NuMI. After the first year of operations, ICARUS will commence its search for evidence of a sterile neutrino jointly with the SBND near detector, within the Short Baseline Neutrino (SBN) program. The ICARUS exposure to the NuMI beam will also give the possibility for other physics studies such as light dark matter searches and neutrino-Argon cross section measurements. The proposed contribution will address ICARUS achievements, its status and plans for the new run at Fermilab and the ongoing developments of the analysis tools needed to fulfill its physics program.
Speaker: Christian Farnese (INFN Padova) -
17:45
The STEREO search for a sterile neutrino at the ILL reactor with full data sample 15m
Loïc-René LABIT, on behalf of the STEREO collaboration
During the last decades, several parameters describing the neutrino oscillation phenomenon have been characterized thanks to reactor neutrino experiments, in particular the precise measurement of the last-to-be-measured mixing angle $\theta_{13}$.
Following a reactor antineutrino flux re-estimation in 2011, a ∼6% deficit between observed and predicted reactor antineutrino fluxes, known as the Reactor Antineutrino Anomaly, has been observed.
The Reactor Antineutrino Anomaly could be explained by an oscillation toward an additional non-interacting, (thus “sterile”) neutrino. The parameters that best explain the RAA are a mixing angle value of $\sin^{2}(2\theta)$ =0.17 and a mass splitting value of $\Delta m^{2}_{41}$ =2.3 $\textrm{eV}^{2}$.
Additionally, a discrepancy between the measured and predicted antineutrino energy spectrum taking the form of an excess of events around 5 MeV has been observed by several reactor neutrino experiments. This discrepancy has yet to be fully understood but could be caused by incorrect predictions of the neutrino spectra.
The STEREO experiment, located at Institut Laue-Langevin in Grenoble (France), was designed to test the above mentioned oscillation hypothesis independently of shape and rate predictions. The segmented detector, located at ~10 m of a compact reactor core, allows for a measurement of the antineutrino energy spectrum at various baselines, sensitive to the oscillation toward a sterile neutrino that would distort the spectrum differently at each baseline.
The experiment could also help to disentangle isotopic contributions to the neutrino energy spectrum by providing a measurement of the spectrum shape and rate originating from a core with highly enriched (93%)235U.
The experiment took data between November 2016 and November 2020. This talk will present the latest limits set in the oscillation parameter space with the full data sample, amounting to 334 (544) days of reactor-on (off), as well as the updated rate and spectrum shape measurements.Speaker: Loïc-René Labit (Univ Grenoble Alpes, Univ Savoie Mont Blanc)
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Public lecture
Cazadores de materia oscura
L'Hemisfèric, Ciutat de les Arts i les Ciències
David G. Cerdeño-
20:00
Cazadores de materia oscura 1h
Conferencia de divulgación en L'Hemisfèric
Ciutat de les Artes i les Ciències de València
https://www.cac.es/es/museu-de-les-ciencies/Ciclos-y-conferencias/Actualidad/Conferencia-cazadores-de-materia-oscura.htmlSpeaker: David G. Cerdeño (IFT (UAM-CSIC))
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GW astrophysics (future discoveries) 30m
Chair: Claudia Lazzaro
Speaker: Paul Lasky (Monash Univ) -
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Gravitational-wave and multi-messenger observations: results and prospects 30m
Chair: Claudia Lazzaro
Speaker: Marica Branchesi (GSSI and Gran Sasso Lab) -
15:30
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Break 30m
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Gamma-ray astronomy from space 30m
Chair: Carlos Delgado
Speaker: Regina Caputo (NASA Goddard Space Flight Center) -
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Gamma-ray astronomy from the ground 30m
Chair: Carlos Delgado
Speaker: Gabrijela Zaharijaš (Nova Gorica U) -
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Discussion Panel Cosmology 3
Chair: Mar Bastero-Gil
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Screening vs. gevolution: in chase of a perfect cosmological simulation code 15m
We compare two competing relativistic approaches to the N-body simulation of the Universe large-scale structure. To this end, employing the corresponding alternative computer codes ("gevolution" and "screening"), we conduct a series of cosmological simulations in boxes of different sizes and calculate the power spectra of the scalar perturbation Φ, the frame-dragging vector potential B and the difference between scalar modes χ=Φ−Ψ. We demonstrate that the corresponding power spectra are in very good agreement between the compared schemes. For example, the relative difference of the power spectra for Φ is 0.04% maximum. Since the perturbed Einstein equations have much simpler form in the "screening" approach, the simulation with this code consumes less computational time, saving almost 40% of CPU hours.
Speaker: Maxim Eingorn (North Carolina Central University) -
17:25
Turnaround physics beyond spherical symmetry 15m
The concept of turnaround radius in an accelerating universe is generalized to arbitrarily large deviations from spherical symmetry, as needed for astronomical observations. As an application, the turnaround surface is characterized when deviations from spherical symmetry are small and is extended to scalar-tensor gravity. An independent approach for small non-sphericities using the Hawking quasilocal energy produces the same result.
[Based on A Giusti & V. Faraoni 2021, Phys. Rev. D 103, 044049 (arXiv:1911.05130); 2019, Phys. Dark Universe 26, 100353 (arXiv:1905.04263)]Speaker: Valerio Faraoni (Bishop's University) -
17:40
Recovering BAO in a SKA intensity mapping survey 15m
The radio-observatory Square Kilometre Array (SKA) will have great potential to map the large-scale structure of the Universe. HI Intensity Mapping is one of the main planned surveys, that will map neutral hydrogen (HI) using large angular pixels, but which will be able to reconstruct the three dimensional LSS of the Universe at very large scales (0 < z < 6). We study the clustering of HI intensity maps produced from simulations with a focus on baryonic acoustic oscillations (BAO) and the effects induced by telescope beam smoothing and foreground cleaning. We start by creating an HI catalogue based on the Semi-Analytic Galaxy Evolution (SAGE) model applied to the z = 1.321 snapshot of the UNIT simulations. With this catalogue we investigate the relation between model HI and the dark matter haloes and we also study the abundance of HI, predicted by this model. We then create synthetic HI intensity maps with a Nearest-Grid-Point approach. In order to simulate the telescope beam effect, a Gaussian smoothing is applied on the plane perpendicular to the line of sight. The effect of foreground removal methods is simulated by exponentially damping the largest wavelength Fourier modes on the radial direction. We study the anisotropic 2-point correlation function (2PCF) and how it is affected by the aforementioned observational effects. In order to better isolate the BAO signal, we study several 2PCF mu-wedges (with a restricted range of orientations) tailored to address the systematics effects and we compare them with different definitions of radial 2PCFs. Finally, we discuss our findings in the context of an SKA-like survey, finding a clear BAO signal in most of the estimators here proposed. Based on 2105.10454
Speaker: Bernhard Vos Ginés (Universidad Autónoma de Madrid) -
17:45
Aspects of High Scale Leptogenesis with Low-Energy Leptonic CP Violation 15m
Using the density matrix equations (DME) for high scale leptogenesis based on the type I seesaw mechanism, in which the CP violation (CPV) is provided by the low-energy Dirac or/and Majorana phases of the neutrino mixing (PMNS) matrix, we investigate the 1-to-2 and the 2-to-3 flavour regime transitions, where the 1, 2 and 3 leptogenesis flavour regimes in the generation of the baryon asymmetry of the Universe $\eta_B$ are described by the Boltzmann equations. Concentrating on the 1-to-2 flavour transition we determine the general conditions under which $\eta_B$ goes through zero and changes sign in the transition. Analysing in detail the behaviour of $\eta_B$ in the transition in the case of two heavy Majorana neutrinos $N_{1,2}$ with hierarchical masses, $M_1 \ll M_2$, we find, in particular, that i) the Boltzmann equations in many cases fail to describe correctly the generation of $\eta_B$ in the 1, 2 and 3 flavour regimes, ii) the 2-flavour regime can persist above (below) $\sim 10^{12}$ GeV ($\sim 10^9$ GeV), iii) the flavour effects in leptogenesis persist beyond the typically considered maximal for these effects leptogenesis scale of $10^{12}$ GeV. We further determine the minimal scale $M_{1\text{min}}$ at which we can have successful leptogenesis when the CPV is provided only by the Dirac or Majorana phases of the PMNS matrix as well as the ranges of scales and values of the phases for having successful leptogenesis. We show, in particular, that when the CPV is due to the Dirac phase $\delta$, there is a direct relation between the sign of $\sin \delta$ and the sign of $\eta_B$ in the regions of viable leptogenesis in the case of normal hierarchical light neutrino mass spectrum; for the inverted hierarchical spectrum the same result holds for $M_1 < 10^{13}$ GeV. The considered different scenarios of leptogenesis are testable and falsifiable in low-energy neutrino experiments.
Speaker: Alessandro Granelli (SISSA) -
17:45
Primordial non-Gaussianity from the angular clustering: prospects for DES 15m
Primordial non-Gaussianity (PNG) is claimed to be a smoking gun to differentiate between the vast collection of inflationary models. The current constraints on PNG, parametrized by $f_{NL}$, are obtained from the CMB, which has reached the cosmic variance limit. A promising way to look for PNG is using the Large Scale Structures (LSS) of the universe, with the potential of breaking the $\sigma(f_{NL})\sim1$ barrier.
In this talk, I will present an analysis of the methods for looking at Primordial non-Gaussianity in the Large Scale Structure of the Universe, with the main focus on the Dark Energy Survey (DES).
We use the Angular Correlation Function (ACF) and show how it is modified by Primordial Non-Gaussianity via a scale-dependent bias (Dalal et al. 2008). One of the main focus of the work is on the integral constraint (IC) condition, which is found to be key to obtain unbiased PNG constraints. The IC corrects for the fact that the mean density of the Universe is measured from the observed galaxies.
The methods are analyzed and optimized for two kinds of simulations: COLA mocks that follow the DES angular and redshift distribution and N-Body simulations with non-Gaussian initial conditions. With the aforementioned simulations, we focus on optimizing the methods to constraint $f_{NL}$ to obtain precise and unbiased results, preparing the ground for the DES Y3 data. We highlight the potential that DES and future photometric surveys could have in constraining PNG.Speaker: Walter Riquelme (IFT UAM-CSIC) -
17:45
Solid matter with zero shear modulus in flat universe 15m
For a perfect fluid, the quantity defined through mixed components of the stress-energy tensor $\widetilde{w}=(T_{i}^{\phantom{i}i}/3)/(-T_{0}^{\phantom{0}0})$ is independent on the choice of coordinates only for two values of the pressure to energy density ratio $w=p/\rho$: for radiation with $w=1/3$, and for dark energy with $w=-1$. With other choices of $w$, the quantity $\widetilde{w}$ is coordinate dependent, and $\widetilde{w}=w$ only in the local rest frame of the fluid. We show that the same is true also for solid matter with shear stress Lamé coefficient set to zero in a flat Friedmann-Lemaitre-Robertson-Walker universe with perturbed metric as well as stress-energy tensor. We call the two different solids with coordinate independent $\widetilde{w}$ radiation-like solid and dark energy-like solid, and we restrict ourselves to these two special cases. By analysing second order perturbations we discover two one parametric sets of such solid matter models containing special cases of radiation and dark energy as perfect fluids. We also study equations for perturbations up to the second order for both sets of models.
Speaker: Peter Mészáros (Department of Theoretical Physics, Comenius University in Bratislava, Slovakia) -
17:45
Warming Up Cold Inflation 15m
The axion is a well-motivated candidate for the inflaton, as the radiative corrections that spoil many single-field models are avoided by virtue of its shift symmetry. However, axions generically couple to gauge sectors. As the axion rolls through its potential, this coupling can result in the production of a co-evolving thermal bath, a situation known as "warm inflation." Inflationary dynamics in this warm regime can be dramatically altered and result in significantly different observable predictions. In this talk, I will show that for large regions of parameter space, axion inflation models once assumed to be safely "cold" are in fact warm, and must be reevaluated in this context.
Speaker: Saarik Kalia (Stanford University)
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Discussion Panel Dark Matter 6
Chair: David G. Cerdeño
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Dark matter search results from DAMIC at SNOLAB 15m
The DAMIC experiment employs large area, thick charge-coupled devices (CCDs) to search for the interactions of low-mass dark matter (DM) particles in the galactic halo with silicon atoms in the CCD target. The low pixel noise provides DAMIC with sensitivity to ionization signals of only a few charges, for a remarkably low energy threshold. From 2017 to 2019, DAMIC collected dark-matter search data with a seven-CCD array (40-gram target) installed in a low radiation environment in the SNOLAB underground laboratory. Results include the search for hidden-sector DM particles with masses as small as a few MeV/$c^2$ from their scattering with electrons. Recently, we performed a search for nuclear recoils from the scattering of WIMPs with GeV/c$^2$-scale masses in a 11 kg day exposure (PRL 125 241803). Our result stands out compared to other experimental searches for low-mass WIMPs because the response to the WIMP signal has been directly calibrated (PRD 94 082007). We probe with the same nuclear target parameter space that corresponds to the WIMP-signal interpretation of the CDMS anomaly (PRL 111 251301), and report a conspicuous excess of events below 200 eV$_{\rm ee}$.
Speaker: Romain Gaior (LPNHE, Sorbonne Université) -
17:25
Improving the sensitivity to light dark matter with the Migdal effect 15m
The search for dark matter (DM) weakly interacting massive particles with noble elements has probed masses down and below a GeV/c^2. The ultimate limit is represented by the experimental threshold on the energy transfer to the nuclear recoil. Currently, the experimental sensitivity has reached a threshold equivalent to a few ionization electrons. In these conditions, the contribution of a Bremsstrahlung photon or a so-called Migdal electron due to the sudden acceleration of a nucleus after a collision might be sizeable. We present a recent work where, using a Bayesian approach, we studied how these effects can be exploited in experiments based on liquid argon detectors. In particular we develop a simulated experiment to show how the Migdal electron and the Bremsstrahlung photon allow to push the experimental sensitivity down to masses of 0.1 GeV/c^2, extending the search region for dark matter particles of previous results. For these masses we estimate the effect of the Earth shielding that, for strongly interacting dark matter, makes any detector blind. Finally, given the relevance of the Migdal electrons to the search for low mass DM, we discuss some new ideas on how to possibly measure such an effect with detectors based on a Time Projection Chamber exposed to an high neutron flux.
Speaker: Grilli di Cortona Giovanni (INFN - Laboratori Nazionali di Frascati) -
17:40
Direct search for low mass dark matter with DarkSide-LowMass 15m
DarkSide-LowMass is a tonne-scale liquid argon time projection chamber being planned by the Global Argon Dark Matter Collaboration (GADMC) to search for WIMP-like dark matter with masses below 10 GeV/c^2, achieving low thresholds with a design optimized for an electron-counting analysis. Building upon the success of DarkSide-50's light dark matter search, DarkSide-LowMass will aim to achieve sensitivity to the solar neutrino floor with a tonne-year exposure. This talk will present sensitivity projections for the DarkSide-LowMass experiment, based on simulations of expected backgrounds.
Speaker: Shawn Westerdale (INFN Cagliari) -
17:45
Dark matter search with a SuperCDMS low-threshold silicon device 15m
The Super Cryogenic Dark Matter Search (SuperCDMS) experiment uses high-sensitivity silicon and germanium detectors to directly search for interactions from galactic dark matter (DM). New 1-gram silicon devices instrumented with ultra-high-resolution phonon sensors can be operated both with no electrical bias in the crystal, measuring the recoil energy, and with an applied electric field, which amplifies the recoil events through the Neganov-Trofimov-Luke effect. In this talk, I will present results from a new search for sub-GeV DM candidates using a modest 0.19 gram-day exposure, acquired with a device characterized by a 9.2 eV trigger threshold. I will also present a study of an unexpected low-energy event excess observed in the silicon device, comparing 0V data to a high voltage data set acquired with the same device. The observed excess is consistent with a Cherenkov/scintillation hypothesis and we expect to be able to mitigate it significantly for the next science campaign, extending the sensitivity to low-mass DM.
Speaker: Valentina Novati (Northwestern University) -
17:45
Direct Dark Matter search with CRESST-III Experiment 15m
CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) is a direct dark matter search experiment located at the Gran Sasso Underground Laboratory (Italy) that uses scintillating cryogenic calorimeters as target material for elastic DM-nucleus scattering. The current phase of the experiment, CRESST-III, is optimized for low-energy nuclear recoil detection. It has reached an unprecedented value of 30 eV for nuclear recoil energy thresholds on a CaWO_4 target, allowing the exploration of low-mass dark matter candidates down to 0.16 GeV/c^{2}. At higher masses the sensitivity is currently limited by a rising event rate (from threshold up to few hundreds of eV) from a so-far unknown origin. Currently dedicated measurements with upgraded detectors — including different target materials — are being performed at the Gran Sasso Underground Laboratory, with the goal of investigating and identifying the origin of the event excess. In this contribution, the current stage of the CRESST-III experiment, together with the most recent dark matter results, will be presented. The potential of the current data taking phase and the sensitivity projections of the next phase of the experiment will be also discussed.
Speaker: Lucia Canonica (Max Planck Institut for Physics) -
17:45
Light Collection for the Scintillating Bubble Chamber (SBC) 15m
The ongoing search for dark matter continues to evolve, and the quest to reach lower cross-sections is leading to novel techniques. A novel low-background technology for the detection of low energy nuclear recoils involves the use of a bubble chamber which employs noble elements (such as argon and xenon) as the active mass to collect additional scintillation data simultaneously. With recent developments in bubble chambers and the added scintillation channel, the scintillating bubble chamber (SBC) collaboration plans to achieve a threshold as low as 100eV and a projected WIMP-sensitivity of 3.0x10-43 cm2, for a WIMP mass of 0.7 GeV/c2. SBC is currently constructing a 10-liter LAr spiked with 100 ppm of LXe chamber at Fermilab with operation scheduled to start mid-2022. One of the most important tasks is to maximize light collection which requires the characterization of 32 Hamamatsu VUV4 SiPMs (silicon photomultipliers). The characterization includes the dark noise rate, photo detection efficiency, and crosstalk as a function of temperature and breakdown voltage. This talk will focus on the scintillation collection system, the current progress of the off-situ characterization of the SiPM array, and preliminary results.
Speaker: Hector Hawley Herrera (Queen's University) -
17:45
Reaching the neutrino floor for sub-GeV dark matter with spherical proportional counters fully electroformed underground 15m
The NEWS-G collaboration has demonstrated the ability to competitively search for light Dark Matter (DM) using spherical proportional counters. SNOGLOBE, the current 1.4 m in diameter detector, was constructed with 99.99% pure copper (C10100). A 500μm ultra-pure copper layer was electroplated to the detector’s inner surface to further suppress backgrounds. Building on this experience, the collaboration is now undertaking the underground construction of entire detectors for unparalleled radiopurity. ECUME, a 1.4 m in diameter detector, will be fully electroformed (EF) in SNOLAB, suppressing both Pb-210 contamination and cosmogenic activation. The construction of a 30 cm in diameter scale model at PNLL will begin imminently, while the construction of ECUME is expected to begin later in 2021. The prototype construction, design and physics potential of ECUME will be discussed. Furthermore, the physics potential of DarkSPHERE, a 3 m in diameter spherical proportional counter currently at the conceptual design stage, will be presented. An improved shielding is foreseen for this detector to reduce external backgrounds to a level matching that of EF copper. New developments in the read-out technology will facilitate operation at higher pressure and potentially provide track reconstruction capabilities. These improvements, along with the increased detector volume, operating pressure, and use of light (H, He, C) gas targets, will enable sensitivity down to the neutrino floor in the sub-GeV DM mass range.
Speaker: Kostas Nikolopoulos (University of Birmingham) -
17:45
Recent status and prospects of CDEX at China Jinping Underground Laboratory 15m
The CDEX program pursues the direct detection of light dark matter candidates with an array of germanium detectors since 2009 at the deepest operating underground site located in Sichuan, China. Searches of modulation effect of light WIMPs [1], WIMPs-nucleus interaction via Midgal effect [2], dark photon model [3], solar axions and axion-like particles [4] as well as the effective-Field-theory-involved interactions [5] have been recently carried out based on the CDEX-1 and CDEX-10 experiments. An upgraded dark matter experiment of the CDEX-50dm is proposed and on-going together with the R&D programs on the key low radioactivity technologies including electroformed copper at the underground site, fabrication and the extra-low-background front-ends of the various germanium detector types, operations of a germanium detector with its bare crystal immersed in liquid nitrogen, possible hybrid Anti-Compton detectors of the mixed PEN and liquid/solid argon as well as radon mitigation of a 1725 meter cube liquid nitrogen tank. Results and the prospects of the CDEX dark matter program will be described and discussed.
- L. T. Yang et al., (CDEX Collaboration) Light WIMPs Search by Annual Modulation Analysis with a Point-Contact Germanium Detector at the China Jinping Underground Laboratory, Phys. Rev. Lett. 123, 221301 (2019)
- Z. Z. Liu et al., (CDEX Collaboration) Constraints on spin-independent nucleus scattering with sub-GeV WIMP dark matter from the CDEX-1B Experiment at CJPL, Phys. Rev. Lett. 123 161301 (2019)
- Z. She et al., (CDEX Collaboration) “Direct Detection Constraints on Dark Photons with CDEX-10 Experiment at the China Jinping Underground Laboratory” Phys. Rev. Lett. 124, 111301 (2020)
- Y. Wang et al. (CDEX Collaboration) “Improved limits on solar axions and bosonic dark matter from the CDEX-1B experiment using profile likelihood ratio method” Phys. Rev. D 101, 052003 (2020)
- Y. Wang et al., (CDEX Collaboration), First experimental constraints on WIMP couplings in the effective field theory framework from CDEX, Sci. China-Phys. Mech. Astron. 64, 281011 (2021)
Speaker: Litao Yang (Tsinghua University) -
17:45
Status of the DAMIC-M dark matter experiment 15m
DAMIC-M is a low-energy threshold dark matter experiment using skipper charge-coupled devices (skipper CCDs) at the Laboratoire Souterrain de Modane (LSM) in France. The kg-scale detector is designed to search for both nuclear and electronic recoils from low-mass WIMP and hidden photon scatters on silicon within the large CCD array. The skipper amplifier readout allows for several non-destructive measurements of individual pixel charge, reducing the detection resolution to single electrons and thus pushing the energy threshold to the eV-scale. We will report the status of the DAMIC-M experiment, including results of recent CCD performance and calibration studies.
Speaker: Danielle Norcini (University of Chicago/KICP) -
17:45
The MIGDAL experiment : Towards observation and measurement of the Migdal effect to help low mass WIMPs searches 15m
The Migdal in Galactic Dark mAtter expLoration (MIGDAL) experiment aims to make the first observation of the Migdal effect from fast neutron scattering using intense DT and DD generators, allowing the effect to be investigated over a wide range of nuclear recoil energies.
The experiment will use an Optical Time Projection Chamber equipped with glass-GEMs operating in 50-Torr CF4 based gas mixture , with light and change readout provided by a CMOS camera, a photomultiplier tube, and a 120 strip anode. This will allow precise three-dimensional reconstruction of the ionization tracks from electron and nuclear recoils.
A Migdal event will be identified by two ionization tracks sharing the same vertex, one belonging to a nuclear recoil and the other to a Migdal electron. Low pressure gas will enable the reconstruction of low energy tracks of electrons down to energies of 5 keV.
We will present the simulations of the events from electrons and nuclear recoils and report on the status of construction of the experiment at the Neutron Irradiation Laboratory for Electronics (NILE) of the Rutherford Appleton Laboratory, UK.Speaker: Pawel Majewski (STFC/Rutherford Appleton Laboratory) -
17:45
The Search for Light Dark Matter with the NEWS-G Detector 15m
The NEWS-G direct dark matter search experiment uses spherical proportional counters (SPC) with light noble gases to explore low WIMP masses. The first results obtained with an SPC prototype operated with Ne gas at the Laboratoire Souterrain de Modane (LSM) have already set competitive results for low-mass WIMPs. The forthcoming next phase of the experiment consists of a large 140 cm diameter SPC installed at SNOLAB with a new sensor design, lots of improvements in detector performance and data quality. Before its installation at SNOLAB, the detector was commissioned with pure methane gas at the LSM, with a temporary water shield, offering a hydrogen-rich target and reduced backgrounds. After giving an overview of the several improvements of the detector, preliminary results of this campaign will be presented, including UV laser and Ar-37 calibration data.
Speaker: Daniel Durnford (University of Alberta) -
17:45
WIMP dark matter searches with CDEX and TEXONO experiments 15m
We present results on light weakly interacting massive particle (WIMP) searches with time-integrated (TI) and annual modulation (AM) analysis on data from a 1-kg mass p-type point-contact germanium detector of the CDEX-1B experiment at the China Jinping Underground Laboratory. Limits from WIMP-nucleus with Migdal effect and WIMP-electrons interactions with earth scattering correction will be discussed. We also present results from spin-independent WIMP-nucleus scattering of TEXONO experiment at earth's surface, which is able to explore parameters space that is blind to underground experiment due to earth scattering.
Speaker: Hau-Bin Li (Institute of Physics, Academia Sinica, Taipei)
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Discussion Panel Dark Matter 7
Chair: Rebecca Gozzini
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Antimatter Cosmic-Ray Nuclei and Dark Matter 15m
Antimatter cosmic-ray measurements can advance our understanding of high-energy astrophysical phenomena in our own Galaxy. Over the last years, satellite experiments as the Alpha Magnetic Spectrometer on board the International Space Station measure antimatter cosmic ray fluxes, including antiprotons and recently antimatter nuclei. These measurements provide a novel probe to search for new physics including annihilations of dark matter in the Milky Way. I will discuss recent studies of the cosmic-ray antiproton-to-proton ratio that have identified an excess of ∼10–20 GeV antiprotons relative to the predictions of standard astrophysical models. Intriguingly, the properties of this excess are consistent with the same range of dark matter models that can account for the long-standing excess of γ-rays observed from the Galactic Center. Such dark matter candidates can also produce significant fluxes of anti-deuterium and anti-helium nuclei , which I will also present.
Speaker: Ilias Cholis (Oakland University) -
17:25
Searching for WIMPs in the Large Magellanic Cloud 15m
We present a radio search for WIMP dark matter in the Large Magellanic Cloud (LMC). We make use of a recent deep image of the LMC obtained from observations of the Australian Square Kilometre Array Pathfinder (ASKAP), taken as part of the Evolutionary Map of the Universe (EMU) survey. LMC is an extremely promising target for WIMP searches at radio frequencies because of the large J-factor and the presence of a substantial magnetic field. We detect no evidence for emission arising from WIMP annihilations and derive stringent bounds. This analysis excludes the thermal cross section for masses below 480 GeV and annihilation into quarks, setting one of the most stringent bounds on WIMPs from indirect searches.
Speaker: Marco Regis (University of Torino and INFN) -
17:45
Constraining Dark Matter Annihilation with Cosmic Ray Antiprotons using Neural Networks 15m
The interpretation of indirect detection experiments searching for dark matter annihilations requires computationally expensive simulations of cosmic-ray propagation. We present a new method based on Recurrent Neural Networks (RNNs) that significantly accelerates simulations of secondary and dark matter cosmic ray antiprotons. This approach allows for an efficient marginalization over the nuisance parameters of a cosmic ray propagation model in order to perform parameter scans for a wide range of dark matter models. We present resulting constraints using the most recent AMS-02 antiproton data on dark matter WIMP models. The speed-up achieved with our method results in a runtime two orders of magnitude below a conventional MCMC approach, once the neural network has been trained.
Speaker: Kathrin Nippel (RWTH Aachen University) -
17:45
Indirect Dark Matter searches towards the Sun with ANTARES neutrino telescope 15m
Dark matter particles, produced in astrophysical sources and gravitationally captured in massive celestial objects, can be indirectly detected through their annihilation into Standard Model particles.
The centre of those massive objects is, therefore, a place where to look for a possible neutrino excess from dark matter annihilations, using neutrino telescopes.
The deep-sea neutrino telescope ANTARES, located in the Mediterranean Sea, has shown to be very competitive on the quest for dark matter WIMPs produced in the Galactic Center.
The closest promising DM source is the Sun, where it is possible to have a very clean signal since the background from astrophysical sources is not expected.
In this work we show the results on the search for dark matter WIMPs from the Sun, using 13 years of data collected by ANTARES.Speaker: Chiara Poirè (UPV) -
17:45
New Ideas of Probing Sterile Neutrino Dark Matter 15m
Sterile neutrino is a simple and elegant dark matter candidate. In its minimal incarnation, the original Dodelson-Widrow mechanism that explains the relic abundance has been in strong tension with the indirect detection limits. I present the self interacting neutrino scenario, mediated by a Majoron-like scalar or vector boson, as a novel solution to the above tension. It can accommodate new production mechanisms for sterile neutrino dark matter, open up a wide parameter space, and result in a number of testable signatures from laboratory to the cosmos.
Speaker: Yue Zhang (Carleton University) -
17:45
Perspectives for anti deuteron search in cosmic rays with an helium calorimeter 15m
Low energy anti-deuterons in cosmic rays are considered a golden channel for the search of Dark matter annihilations in the Galaxy.
Anti Deuteron Helium Detector (ADHD) project is aiming to study the signature offered by an high pressure Helium target for the identification of anti-deuterons in cosmic rays.
In particular exotic atoms are produced by stopping anti-protons/anti-deuterons in the gas and the captured particle can orbit the Helium nucleus for microseconds before the annihilation. This meta-stability is a unique feature for the Helium target and the characteristic delayed annihilation is a distinctive signature to identify the antimatter nature of the stopping particle.
A possible configuration for ADHD space/balloon detector consists of a pressurized helium calorimeter surrounded by scintillator layers for velocity measurement.
Anti-deuterons are identified by combining the spectrometric measurement of the stopping particle (velocity/energy) with the delayed emission of outgoing charged pions caused by the annihilation.
A prototype of the pressurized calorimeter, filled by 200 Bar Helium acting as a scintillator, has been characterized with cosmic muons and with 70-240 MeV proton beam in the INFN-TIFPA laboratory.
Sensitivity of the possible Anti-Deuteron-Helium-Detector for the measurement of low energy anti-deuterons and anti-protons in cosmic rays will be summarized and the results of the measured performance of the helium calorimeter prototype will be shown.Speaker: Francesco Nozzoli (Istituto Nazionale Fisica Nucleare (INFN) - TIFPA) -
17:45
The GAPS experiment - Searching for Dark Matter using Cosmic-ray Antinuclei 15m
The General Antiparticle Spectrometer (GAPS) is a balloon-borne detector designed to search for dark matter search by measuring low-energy (<0.25 GeV/n) cosmic-ray antinuclei (antiprotons, antideuterons, antihelium). GAPS uses a novel identification technique based on exotic atom formation and decay. GAPS will provide a high-statistics antiproton spectrum in an unexplored low-energy range. In contrast, so far, no antideuteron has been detected in cosmic radiation. However, well-motivated theories beyond the standard model of particle physics predict a significant enhancement of the antideuteron flux at low energies due to the annihilation or decay of dark matter particles.
Antideuterons are an essentially background-free dark matter signature since, below 0.25 GeV/n, the astrophysical background is predicted to be at least two orders of magnitude lower than the flux predicted from viable dark matter models. GAPS will also provide leading sensitivity to cosmic antihelium-3, a particularly low-background signature of new physics. The experiment is designed to achieve its goals via a series of long-duration balloon flights at high altitude in Antarctica starting in Austral Summer 2022/2023. This presentation will review the theoretical status of antinuclei searches for dark matter, introduce the GAPS experiment, and report on the status of the GAPS instrument construction, simulation, and analysis tools.Speaker: Riccardo Munini (INFN - Trieste) -
17:45
Underground detections of an extra gauge interacting sterile neutrino dark matter 15m
We show that decay products from sterile neutrino dark mater in extra U(1) models are detectable in both direct dark matter detection experiments and neutrino telescope. The sterile neutrino dark matter interacts with a light gauge boson and decays into neutrinos. Those neutrinos could scatter off nuclei with a large enough recoil energy in direct dark matter detection experiments as WIMPs do.
Speaker: Osamu Seto
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Discussion Panel Gravitational Waves 2
Chair: Toni Font
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Towards a gravitational-wave catalogue of boson-star mergers 15m
Advanced LIGO and Virgo have delivered a conclusive gravitational-wave signal consistent with compact binary mergers in the intermediate-mass black-hole range and as well as several lower significance triggers. These signals have challenged in several ways our vanilla analysis methods, all done within the “canonical” paradigm of quasi-circular black hole mergers. First, under such assumption, GW190521 points to the existence of a black-hole in the PISN gap. Second, analyses performed on the lower significance trigger S200114f with different waveform families report inconsistent results. The barely observable pre-merger emission of these signals, however, allows for the consideration of alternative scenarios both within and beyond the black-hole merger one. In this talk, we will present an analysis of GW190521 and S200114f within the paradigm of the merger of horizonless compact objects known as boson (Proca)-stars, providing estimates of the mass of the underlying ultralight bosons. This could be the first step towards the construction of an eventual catalogue of mergers of compact exotic objects.
Speaker: Juan Calderon Bustillo (Galician Institute of High Energy Physics (IGFAE)) -
17:25
The search of higher multipole radiation in gravitational waves from compact binary coalescences by a minimally-modelled pipeline 15m
The coherent WaveBurst (cWB) pipeline implements a minimally-modelled search to find a coherent response in the network of gravitational wave detectors of the LIGO-Virgo Collaboration in the time-frequency domain. Here we describe an extension of the cWB analysis to detect spectral features beyond the main quadrupolar emission of gravitational waves during the inspiral phase of compact binary coalescences. The search is performed by defining specific regions in the time-frequency map to extract the energy of harmonics of main quadrupole mode in the inspiral phase. The shapes of these regions are fixed by a mild optimization of their Receiver Operating Characteristic curves. This method has already been used in the GW190814 discovery paper (ref. ApJ). Here we describe in full detail the procedure to detect the (3, 3) multipole in GW190814 within the cWB framework, as well as additional searches for other subdominant modes. We also apply this method on another event that displays possible higher multipoles, GW190412.
Keywords: gravitational waves, analysis, multipoles, compact binary coalescences
Speaker: Odysse Halim (INFN Trieste) -
17:40
Searching gravitational wave echoes in the post-merger phase after a binary black hole coalescences. 15m
Current gravitational wave (GW) surveys of binary black hole (BBH) mergers provide unprecedented probes of the dynamics in extreme gravitational fields and relativistic velocities.
It has been proposed that such compact objects may display exotic characteristics and could produce repeated GW pulses of widely uncertain morphology (echoes) in the post-merger phase. A detection of echoes would be a smoking gun on the existence of exotic compact objects (ECOs) and would shed light on their nature and their constituents.
We will present a method to search for echoes that is agnostic to the properties of the GW pulses and it is based on a targeted version of coherentWaveBurst (cWB), the unmodelled GW transient search algorithm, developed in the LIGO Scientific Collaboration (LSC) and Virgo Collaboration and widely used on LIGO-Virgo-KAGRA data.
We will discuss the results of this search on LIGO-Virgo open data and provide new upper limits in terms of the detectable energy of echo-like signals. We will present some constraints that these observations set on the parameters space of ECOs' models.Speaker: Andrea Miani (Virgo, cWB Trento-Padova group) -
17:45
Characterizing the observation bias in gravitational-wave detections and finding structured population properties 15m
The observed distributions of the source properties from gravitational-wave detections are biased due to the selection effects and detection criteria in the detections, analogous to the Malmquist bias. In this work, this observation bias is investigated through its fundamental statistical and physical origins. A semi-analytical formulation for its estimation for a network of detectors is derived which is more efficient and precise than the standard method of numerical simulations, with only a fraction of the computational cost. Then, the estimated bias is used for model-independent inferences on the binary black hole population. These inferences show additional structures, specifically two potential mass gaps in the joint mass distribution, which were not found via modelled inferences.
Speaker: Doğa Veske -
17:45
Probing the Ultralight Boson with the Ringdown Phase of Black Hole Mergers 15m
Ultralight bosons are an encouraging class of dark matter candidate particles, which may form long-lived bosonic clouds surrounding rotating black holes via superradiance. We compute the shifts in the gravitational quasinormal-mode frequencies of supermassive black holes due to the presence of such a bosonic cloud. We then use the modified ringdown waveform of a supermassive black hole from a surrounding bosonic cloud as a novel probe of the existence of a potential ultralight boson of mass $ \in [10^{-16}, 10^{-18} ] \rm eV$. Because the ringdown signal of a binary merger is significantly shorter than the inspiral, our ringdown test of the ultralight boson can probe masses on timescales relatively shorter than inspiral-based, stochastic, or population-based search methods.
Speaker: Joseph Gais -
17:45
Search for Black Hole Merger Families 15m
The origin, environment, and evolution of stellar-mass black hole binaries are still a mystery. One of the proposed binary formation mechanisms is manifest in dynamical interactions between multiple black holes. A resulting framework of these dynamical interactions is the so-called hierarchical triple merger scenario, which happens when three black holes become gravitationally bound, causing two successive black hole mergers to occur. In such successive mergers, the black holes involved are directly related to each other, and hence this channel can be directly tested from the properties of the detected binary black hole mergers. Here we present a search for hierarchical triple mergers among events within the GWTC-1 and GWTC-2 catalogs of LIGO/Virgo, the eccentric localization of GW190521 and those found by the IAS-Princeton group. We perform our analysis for different upper bounds on the mass distribution of first generation BHs. Our results demonstrate the importance of the mass distributions' properties for constraining the hierarchical merger scenario. We present the individually significant merger pairs. The search yields interesting candidate families and hints of its future impact.
Speaker: Doğa Veske (Columbia U.) -
17:45
The impact of IMBHs on properties of binary black holes originating from Globular Clusters 15m
Stellar mass binary black holes are the most important sources of gravitational waves for current LIGO-Virgo-Kagra detectors. We analyze about a thousand globular cluster (GC) models simulated using the MOCCA Monte Carlo code for star cluster evolution to study black hole - black hole interactions in these dense stellar systems that can lead to gravitational wave emission. We extracted information for all coalescing binary black holes (BBHs) that merge via gravitational radiation from these GC models and for those BHs that collide due to 2-body, 3-body and 4-body
dynamical interactions. By obtaining results from a substantial number of realistic star clusters evolution model, that cover different initial parameters (masses, metallicities, densities etc) we have an extremely large statistical sample of two black holes which merge or collide within a Hubble time. The existence of Intermediate Mass Black Hole, with masses 100-1000 solar masses, strongly infuences the results. We study also properties of BBHs escaping from globular clusters. Some of them contain IMBH. We discuss the importance of BBH originating from GC for gravitational waves observations.Speaker: Dorota Gondek-Rosinska (University of Warsaw)
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Discussion Panel HE astrophys. & CRs/Multi-messenger astronomy 2
Chair: Ioana Maris
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Gamma-ray image reconstruction of the Andromeda galaxy 15m
Andromeda galaxy (M31) represents our nearest large neighbor spiral galaxy with a distance of 785 kpc. Its close proximity allows us to optically resolve its stellar disk and bulge as two separate components. Although M31 spans 3.2º x 1º on the sky in optical light, the determination of its extension in γ rays remains controversial. We analyze about 12 years of Fermi-LAT data using the code skyFACT which combines template fitting and image reconstruction. In this work, we robustly characterize its spectral and morphological properties against systematic uncertainties related to the modeling of the Galactic diffuse emission. We present for the first time a proper comparison of non-nested models describing M31 morphology and show the reconstruction of its γ-ray image in a template-independent way in order to identify its components.
Speaker: Celine Armand (Astronomy department, University of Geneva) -
17:25
Multimessenger Astronomy of Transient Point Sources at the Pierre Auger Observatory 15m
One of the key challenges in astroparticle physics is the identification of the sources of cosmic rays at the highest energies (above 1 EeV). In this context, the search for neutral messenger particles in the ultra-high-energy (UHE) regime is of high interest. The sources of the gravitational waves (GWs) that can be observed with the current generation of GW detectors provide extreme astrophysical environments that are most likely to be unique in the universe. Another extraordinary source candidate is the anomalous blazar TXS 0506+056 which has been found to be coincident with two periods of enhanced high-energy neutrino flux in 2014/15 and 2017 as reported by the IceCube Collaboration. Due to their distance and transient nature, the capabilities of these sources to produce UHE radiation can only be studied through neutral messengers like photons and neutrinos.
The Pierre Auger Observatory near Malargüe, Argentina, is the largest air-shower experiment for the detection of UHE cosmic rays. With its surface detector, consisting of a grid of 1660 water Cherenkov detectors covering an area of 3000 km², it has a unique exposure to UHE photons and neutrinos and has published first constraints on these particles from GW sources and TXS 0506+056.Speaker: Philip Ruehl (University of Siegen) -
17:40
Unveiling the origin of steep decay in 𝛾-ray bursts 15m
γ-ray bursts (GRBs) are transient cataclysmic events, whose role became central in the new multi-messenger era. In the present work I propose a novel investigation of the GRB emission mechanism, via time-resolved spectral analysis of the X-ray tails of bright GRB pulses observed with the XRT instrument onboard the Neil Gehrels Swift Observatory, discovering a unique relation between the spectral index and the flux. The investigation of the spectral evolution during the GRB tail is an ideal diagnostic to understand the connection between the emission processes, the cooling processes and the outflow environment. I thoroughly discuss possible interpretations in relation to current available models and I show the incompatibility of our results with the standard high latitude emission scenario. Our results for the first time strongly suggest evidence of adiabatic cooling of the emitting particles, shedding light on fundamental physics of relativistic outflows in GRBs. Finally I discuss the crucial role of future wide-field X-ray telescopes, such as the mission concept Theseus, for the characterisation of the GRB tail emission, highlighting also its importance in the multi-messenger context.
Speaker: Samuele Ronchini (Gran Sasso Science Institute) -
17:45
CTA prospects for annihilating dark matter from observations of nearby spiral galaxies 15m
TBC
Speaker: Miltiadis Michailidis (Univ Tübingen (IAAT)) -
17:45
Intergalactic electromagnetic cascade echo from GRB 190114C 15m
Primary very high energy (VHE, E>100 GeV) gamma-rays from distant (redshift z>0.1) extragalactic gamma-ray sources are partially absorbed on extragalactic background light (EBL) photons by means of the pair production process \gamma\gamma\rightarrow e^{+}e^{-} with the subsequent formation of intergalactic electromagnetic cascades through inverse Compton scattering of secondary electrons (mostly on cosmic microwave background (CMB) photons). These electrons get deflected in the extragalactic magnetic field (EGMF); therefore, the parameters of the observable gamma-ray flux are sensitive to the EGMF strength and structure. The weakest EGMF (magnetic field strength B<100 aG) could, in principle, be probed through the observation of gamma-ray bursts with imaging atmospheric Cherenkov telescopes (IACTs) and space gamma-ray telescopes such as Fermi-LAT. The gamma-ray burst GRB 190114C was detected with the MAGIC IACTs in the 200 GeV – 1 TeV energy range, for the first time allowing us to estimate the observable intensity of cascade gamma-rays robustly. In this work we present detailed calculations of the observable cascade signal for various assumptions about the strenght of the EGMF. We perform an analysis of the publicly available dataset of the Fermi-LAT telescope and derive upper limits on the intensity of the intergalactic pair echo. We show that the sensitivity of Fermi-LAT is not sufficient to obtain any constraints on the EGMF parameters. However, next-generation space gamma-ray observatories would be able to detect pair echoes from GRBs similar to GRB 190114C for the EGMF strength below 1-10 aG.
Speaker: Timur Dzhatdoev (Moscow State University) -
17:45
Observable spectral and angular distributions of gamma-rays from extragalactic ultrahigh energy cosmic ray accelerators: application to extreme TeV blazars 15m
The origin of gamma-ray radiation of extreme TeV blazars (ETBs) — active galactic nuclei with unusually hard observable spectra in the TeV energy region — is still poorly understood. This is especially unfortunate since ETB studies are important in extragalactic background light measurements, and extremely important in extragalactic magnetic field measurements and axion-like particle searches. Besides very hard gamma-ray spectra, ETBs are usually characterized by relatively weak (~dozens of percent) and slow (typical timescale of ~months-years) variability of the gamma-ray flux. These unusual properties of ETBs could in principle be explained if the observable gamma-rays were formed not inside these sources, but rather in the intergalactic medium as a result of the development of electromagnetic cascades. A scenario assuming the primary ultrahigh energy (E>1 EeV) protons — the so-called intergalactic hadronic cascade scenario (IHCM) — enjoyed especially high popularity during the last decade. In the present work we calculate the observable spectrum and angular distribution of observable gamma-rays from extreme TeV blazars in the framework of the IHCM scenario, for the first time taking into account the effect of primary proton deflection in filaments and galaxy clusters of a realistic extragalactic magnetic field. We show that the observable point-like spectrum (i.e. the spectrum inside the point spread function of a typical imaging atmospheric Cherenkov telescope) at multi-TeV energies is significantly softer than the one averaged over all values of the observable angle. The width of the observable angular distribution at E>10 GeV is greater than or comparable to the extent of the point spread function of operating and next-generation gamma-ray telescopes. These results imply that electromagnetic cascades from primary ultrahigh energy protons do not enhance the effective transparency of the Universe in the very high energy range significantly. The reported study was funded by RFBR, Russia, project number 20-32-70169.
Speaker: Timur Dzhatdoev (Moscow State University) -
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Searches for sub-PeV photons in coincidence with neutrinos 15m
The mechanisms of origin of ultrahigh-energy gamma radiation are poorly studied. One way to find out is to search for temporal and directional coincidences of high-energy galactic neutrinos with photons of similar energies. The results of such a search could provide indications of the hadronic origin of this radiation. In this paper, we report on the search for photons with energies above 300 TeV in coincidence with high-energy neutrinos. The searches of ultrahigh-energy gammas were carried out at the Carpet-2 EAS array, using three years of data taking.
Speaker: Viktor Romanenko (The Institute for Nuclear Research of the Russian Academy of Sciences) -
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Searching for High-Energy Neutrinos from Ultra-Luminous Infrared Galaxies with IceCube 15m
This work presents an IceCube search for high-energy neutrinos from Ultra-Luminous Infrared Galaxies (ULIRGs). ULIRGs are the most luminous infrared objects on the sky, with infrared luminosities exceeding $10^{12}$ solar luminosities. They are mainly powered by starbursts that exhibit star-formation rates larger than 100 solar masses per year. In addition, an active galactic nucleus (AGN) can also contribute significantly to the ULIRG luminosity output. The acceleration of hadrons, and consequently the production of neutrinos, can occur both in starburst and AGN environments. As such, ULIRGs form a source population that could be responsible for a significant fraction of the diffuse neutrino flux observed by IceCube. In this study we perform a stacking analysis on a representative sample of 75 ULIRGs with redshift $z \leq 0.13$ using 7.5 years of IceCube data. We find no evidence for astrophysical neutrinos correlated with our selection of ULIRGs. We therefore compute upper limits on the contribution of the ULIRG source population to the diffuse neutrino observations, and also use these limits to constrain model predictions.
Speaker: Pablo Correa (Vrije Universiteit Brussel) -
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The Search for Ultra-High Energy Neutrinos through Highly Inclined Air Showers in the Pierre Auger Observatory 15m
The Surface Detector of the Pierre Auger Observatory, an array of 1600 water-
Cherenkov stations in a triangular grid with 1500 m separation between
stations, has the capability to detect neutrinos with energy above 10^17 eV. The
identification through the special characteristics of highly inclined showers is
efficiently performed for neutrinos of all flavours interacting deep in the
atmosphere at large zenith angles as well as for Earth skimming τ neutrinos.
In this talk I review the status of the neutrino search at the Observatory using
about 15 years of data. Restrictive upper bounds on the neutrino flux from
diffuse sources and from point-like steady sources were stablished placing
strong constraints on several models of neutrino production at EeV energies
and on the properties of the sources of ultra-high-energy cosmic rays.
Unrivaled sensitivity in searches for transient sources has been also achieved.Speaker: Gonzalo Parente (Universidade de Santiago de Compostela) -
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Unveiling the complex correlation patterns and emission mechanisms in Mrk 421 15m
The blazar Mrk421 (redshift z=0.031) is one of the brightest and closest BL Lac type objects, making it an ideal target to probe blazar jet physics. We present a detailed characterisation and theoretical interpretation of the broadband emission of Mrk 421, with a focus on the multi-band flux correlations. The extensive multi-wavelength observation campaign was organised in 2017, during which the correlation patterns show some disparity and complex behaviours. Observations from several instruments are used to achieve an optimal temporal coverage from radio to TeV energies. In particular, four multi-hour NuSTAR observations organised simultaneously with MAGIC allow to obtain a precise measurement of the falling segments of the two spectral bumps. A detailed investigation of the very-high-energy (VHE; >100 GeV) versus X-ray flux correlation is performed, by binning the data into several sub-energy bands. A positively correlated variability is observed, but the correlation characteristics change substantially across the various bands probed. Furthermore, during the simultaneous MAGIC and NuSTAR observations a clear change of the Compton dominance is detected without a simultaneous change in the synchrotron regime, indicating an "orphan gamma-ray activity". We also investigate an intriguing bright flare at VHE without a substantial flux increase in the X-rays. Within a leptonic scenario, this behaviour is best explained by the appearance of a second population of highly-energetic electrons spanning a narrow range of energies. Finally, our multi-wavelength correlation study also reveals an anti-correlation between the UV/optical and X-ray bands at a significance level above 3 sigma. This behaviour suggests changes in the acceleration and cooling efficiencies of the electrons.
Speaker: Axel Arbet-Engels (ETH Zürich & Max Planck Institute for Physics, Münich)
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Discussion Panel Neutrinos 5
Chair: Georgia Karagiorgi
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JUNO Detector Design & Status 15m
The Jiangmen Underground Neutrino Observatory (JUNO) is a next-generation liquid-scintillator reactor neutrino experiment under construction in Southern China. It is a multi-purpose experiment with a wide range of applications in neutrino physics, ranging from a mass-ordering (MO) determination to solar, geo-, and atmospheric neutrinos, detecting of Supernova neutrinos, and precision measurement on oscillation parameters. The JUNO central detector (CD) designs to an energy resolution of 3% at 1 MeV. The detector system will install in an over 50-meter-wide experimental hall, which recently excavates under 700 m of granite overburden. The CD contains a 35.4-meter diameter acrylic vessel filled with 20-kt of LAB-based liquid scintillator, making it the largest liquid-scintillator detector in the world. The scintillation light will be read-out by 17612 20" PMTs and 25600 3" PMTs, reaching a high photocathode coverage higher than 75%. The CD surrounds a water pool filled with ultrapure water equipped with 2400 PMTs; on top of the CD, a tracker completes the JUNO veto system for cosmic muons detection.
JUNO construction will complete in 2022. This talk presents the detector design and status of the experiment.Speaker: Zhimin Wang (IHEP,CAS) -
17:25
The Intermediate Water Cherenkov Detector for the Hyper-Kamiokande Experiment 15m
Hyper-Kamiokande (Hyper-K) is a next-generation experiment for understanding the properties of neutrino mixing, astrophysical neutrinos, and searches for new physics through processes such as nucleon decay. It will utilize a water Cherenkov detector 8 times larger than the current Super-Kamiokande, and will benefit from an upgraded 2.5 times higher intensity J-PARC beam than T2K. An Intermediate Water Cherenkov Detector (IWCD) will help mitigate systematic uncertainties to a level commensurate with this unprecedented statistical precision, affording significant discovery potential of leptonic CP violation. This one kilotonne scale detector will be located around 1 km from the J-PARC neutrino source. The capability to move vertically for scanning off-axis angles will improve the understanding of neutrino interactions and their energy dependence. Gadolinium loading will allow high efficiency measurements of neutrons that accompany neutrino interactions, providing further knowledge towards Hyper-K physics analyses. A prototype water Cherenkov beam test experiment (WCTE) is planned at CERN to evaluate key technologies, including a new photosensor, calibration systems, and deep learning event reconstruction. This talk will summarize the WCTE and IWCD designs and physics programs.
Speaker: Patrick de Perio (TRIUMF) -
17:40
RES-NOVA: archaeological Pb-based observatory for Supernova neutrino detection 15m
RES-NOVA is a new proposed experiment for the hunt of neutrinos from core-collapse supernovae (SN) via coherent elastic neutrino-nucleus scattering (CEvNS) using an array of archaeological lead (Pb) based cryogenic detectors. The high CEvNS cross-section on Pb and the ultra-high radiopurity of archaeological Pb enable the operation of a high statistics experiment equally sensitive to all neutrino flavors. Thanks to these unique features, RES-NOVA will be as sensitive as super-size SN neutrino observatories, while running a detector with a total active volume of only (60 cm)^3. RES-NOVA will be able to reconstruct the SN neutrino parameters with great accuracy (at the 10% level) and it will be sensitive to SN emissions from the entire Milky Way Galaxy with 5 sigma statistical significance. During this conference, the expected detector performance and sensitivity will be presented, as well as the first preliminary results of a prototype detector.
Speaker: Luca Pattavina (INFN-LNGS & TUM) -
17:45
A deuterated liquid scintillator for supernova neutrino detection 15m
For the next galactic supernova, operational neutrino telescopes will measure the neutrino flux several hours before their optical counterparts. Existing detectors, relying mostly on charged current interactions, are mostly sensitive to $\bar{\nu}_e$ and to a lesser extent to $\nu_e$. In order to measure the flux of other flavors ($\nu_{\mu},\bar{\nu}_{\mu},\nu_{\tau},\text{and}~\bar{\nu}_{\tau}$), we need to observe their neutral current interactions with the detector. Such a measurement is not only crucial for overall normalization of the supernova neutrino flux but also for understanding the intricate neutrino oscillation physics. A deuterium based detector will be sensitive to all neutrino flavors. In this talk, I will present our proposal for a 1\,kton deuterated liquid scintillator (DLS) based detector that will see about 435 neutral current events and 170 (108) charged current $\nu_e$ ($\bar{\nu}_e$) events from a fiducial supernova at a distance of 10 kpc from Earth. We explore the possibility of extracting spectral information from the neutral current channel $\overset{\scriptscriptstyle(-)}{\nu} d \rightarrow \overset{\scriptscriptstyle(-)}{\nu}np$ by measuring the quenched kinetic energy of the proton in the final state, where the neutron in the final state is tagged and used to reduce backgrounds.
Speaker: Bhavesh Chauhan (Tata Institute of Fundamental Research, India) -
17:45
DUNE Physics Program and Status 15m
The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline neutrino experiment with a 70-kt liquid argon detector at the Sanford Underground Research Facility (SURF) 1300 km from Fermilab. This programme includes studies of neutrino oscillations with a high-intensity muon-neutrino beam from Fermilab; as well as, proton decay and supernova neutrino burst searches. DUNE will resolve the neutrino mass hierarchy to a precision of 5σ, for all δCP values, after 2 years of running with the nominal detector design and beam configuration. It has the potential to observe charge-parity violation in the neutrino sector to a precision of 3σ (5σ) after an exposure of 5 (10) years, for 50% of all δCP values. The status and schedule of the project will be also presented.
Speaker: Carmen Palomares (CIEMAT) -
17:45
First tritium endpoint measurement with Cyclotron Radiation Emission Spectroscopy (CRES) 15m
The Project 8 collaboration is seeking a direct measurement of the absolute neutrino mass scale from the distortion of the tritium beta decay spectrum near the endpoint with a sensitivity of $\sim 40\,\mathrm{meV/c^2}$. To this end, the collaboration has successfully established CRES, a frequency-based approach to detect electrons and determine their kinetic energy. This talk will present the data and analysis of the first tritium spectrum recorded using the CRES technique. The spectrum shows no events beyond the endpoint, demonstrating the ultra-low background obtainable with this technology. This talk will further report on the improved energy resolution and the influence of the main systematic error sources on the shape of the measured spectrum and the tritium endpoint determination.
This work is supported by the US DOE Office of Nuclear Physics, the US NSF, the PRISMA+ Cluster of Excellence at the University of Mainz, and internal investments at all institutions.Speaker: Christine Claessens (Center for Experimental Nuclear Physics and Astrophysics, University of Washington, WA, USA) -
17:45
Neutrino Physics in XENONnT 15m
The XENONnT experiment is an ultra-low background liquid xenon Time Projection Chamber at the Gran Sasso National Laboratory in Italy. Beyond its primary science goal to detect WIMP dark matter, XENONnT will be highly sensitive to a variety of rare neutrino processes. The previous XENON1T measured the half-life of the two-neutrino double-electron capture process of Xenon-124. In XENONnT, with a few hundred kilograms of Xenon-136 in the fiducial volume, we will search for hints of neutrinoless double beta decay. Several detector upgrades improve XENONnT's sensitivity to low-energy interactions with neutrinos directly. Through coherent elastic neutrino-nucleus scattering, XENONnT will measure solar Boron-8 neutrinos and neutrinos from a potential galactic supernova. A significant number of solar pp and Beryllium-7 neutrinos are also expected to produce electronic recoils. In this talk, I will give an overview of the impressive capability of the XENONnT detector to observe rare neutrino phenomena.
Speaker: Abigail Kopec (Purdue University, XENON Collaboration) -
17:45
Novel Studies on Neutral Bremsstrahlung in Xenon Optical TPCs 15m
We have measured, for the first time in pure Xe, non-excimer-based secondary scintillation, Neutral Bremsstrahlung (NBrS), in a dedicated setup based on a Gas Proportional Scintillation Counter.
The emission of NBrS by drifting electrons occurs even for electric field values below the gas excitation threshold. We have shown the presence of NBrS in the NEXT-White TPC, at present the largest optical HPXe-TPC in operation.
Moreover, for field values above 1 kV/cm/bar, as typically employed for electroluminescence (EL), there is consistent evidence that NBrS is present with an intensity about two orders of magnitude lower than conventional, excimer-based, EL.
Our data show excellent agreement with calculations of NBrS yield.
Despite fainter than EL, in pure xenon, this new source of emission has to be accounted for in Xe optical TPCs and may play an important role in future single-phase LXe TPCs.Speaker: Cristina M. B. Monteiro (University of Coimbra) -
17:45
Status of Super-Kamiokande Gadolinium project 15m
Super-Kamiokande (SK) is the world's largest underground water Cherenkov
detector. The latest phase of operations began in July 2020 when, in order
to improve neutron detection efficiency, about 13 tons of gadolinium (Gd)
sulfate octahydrate was dissolved into SK's pure water. Gd has a large
thermal neutron capture cross section and emits visible gamma rays. This
first loading marked the start of what is now called SK-Gd, and stable
physics data taking has been ongoing since then.
This presentation will focus on details of the first Gd loading and the
detector status including detector calibrations. Also, the future plan and
the prospect of observations with SK-Gd will be discussed.Speaker: Motoyasu Ikeda (Kamioka Obs. ICRR. U of Tokyo) -
17:45
The Hyper-Kamiokande Experiment 15m
The Hyper-Kamiokande experiment consists of a 260 kt underground water Cherenkov detector with a fiducial volume more than 8 times larger than that of Super-Kamiokande. It will serve both as a far detector of a long-baseline neutrino experiment and an observatory for astrophysical neutrinos and rare decays.
The long-baseline neutrino experiment will detect neutrinos originating from the upgraded 1.3 MW neutrino beam produced at the J-PARC accelerator 295 km away. A near detector suite, close to the accelerator, will help characterise the beam and minimise systematic errors. The experiment is now under construction and due to start data taking in 2027.
The experiment will investigate neutrino oscillation phenomena (including CP-violation and mass ordering) by studying accelerator, solar and atmospheric neutrinos, neutrino astronomy (solar, supernova, supernova relic neutrinos) and nucleon decays.
In this talk, we will present an overview of the Hyper-Kamiokande experiment, its physics goals and the current status.Speaker: Jeanne Wilson (King's College London)
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17:10
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Discussion Panel Neutrinos 6
Chair: Omar Miranda
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17:10
Probing exotic neutrino physics with CEvNS and neutrino-electron scattering 15m
Nuclear and electron recoil measurements are a substantial tool for investigating novel neutrino physics phenomena at low-energies. In this talk I will discuss the current constraints on non-standard interactions (NSIs) and electromagnetic neutrino properties, obtained from the recent observation of coherent elastic neutrino-nucleus scattering (CEvNS) by COHERENT as well as from the recent XENON1T excess of electron recoil events.
Speaker: Dimitrios Papoulias (University of Ioannina) -
17:25
Electromagnetic neutrino: The theory, laboratory experiments and astrophysical probes 15m
In the present talk we continue our discussions [1-5] on neutrino electromagnetic properties and start with a short introduction to the derivation of the general structure of the electromagnetic form factors of Dirac and Majorana neutrinos.
Then we consider experimental constraints on neutrino magnetic and electric dipole moments, electric millicharge, charge radii and anapole moments from the terrestrial laboratory experiments (the bounds obtained by the reactor MUNU, TEXONO and GEMMA experiments and the solar Super-Kamiokande and the recent Borexino experiments). A special credit is done to the most severe constraints on neutrino magnetic moments, millicharge and charge radii [6-10]. The world best reactor [6] and solar [7] neutrino and astrophysical [11,12] bounds on neutrino magnetic moments, as well as bounds on millicharge from the reactor neutrinos [8] are included in the recent issues of the Review of Particle Physics (see the latest Review: P.A. Zyla et al. (Particle Data Group), Prog. Theor. Exp. Phys. 2020, 083C01). The best astrophysical bound on neutrino millicharge was obtained in [13]. The most severe astrophysical bound on neutrino magnetic moment has been obtained recently in [14].
In the recent studies [15] it is shown that the puzzling results of the XENON1T collaboration [16] at few keV electronic recoils could be due to the scattering of solar neutrinos endowed with finite Majorana transition magnetic moments of the strengths lie within the limits set by the Borexino experiment with solar neutrinos [7]. The comprehensive analysis of the existing and new extended mechanisms for enhancing neutrino transition magnetic moments to the level appropriate for the interpretation of the XENON1T data and leaving neutrino masses within acceptable values is provided in [17].
Considering neutrinos from all known sources, as well as including all available data from XENON1T and Borexino, the strongest up-to-date exclusion limits on the active-to-sterile neutrino transition magnetic moment are derived in [18] .
A comprehensive analisys of constraints on neutrino electric millicharge from experiments of elastic neutrino-electron interaction and future prospects involving coherent elastic neutrino-nucleus scattering is presented in [19].
We also present results of the recent detailed study [20] of the electromagnetic interactions of massive neutrinos in the theoretical formulation of low-energy elastic neutrino-electron scattering. The formalism of neutrino charge, magnetic, electric, and anapole form factors defined as matrices in the mass basis with account for three-neutrino mixing is presented. Using the derived new expression for a neutrino electromagnetic scattering cross section [20], we further developed studies of neutrino electromagnetic properties using the COHERENT data [9] and obtained [10] new bounds on the neutrino charge radii from the COHERENT experiment. Worthy of note, our paper [10] has been included by the Editors Suggestion to the Phys. Rev. D “Highlights of 2018”, and the obtained constraints on the nondiagonal neutrino charge radii since 2019 has been included by the Particle Data Group to the Review of Particle Physics.
The main manifestation of neutrino electromagnetic interactions, such as: 1) the radiative decay in vacuum, in matter and in a magnetic field, 2) the neutrino Cherenkov radiation, 3) the plasmon decay to neutrino-antineutrino pair, 4) the neutrino spin light in matter, and 5) the neutrino spin and spin-flavour precession are discussed. Phenomenological consequences of neutrino electromagnetic interactions (including the spin light of neutrino [21]) in astrophysical environments are also reviewed.
The second part of the proposed talk is dedicated to results of our mostly recently performed detailed studies of new effects in neutrino spin, spin-flavour and flavor oscillations under the influence of the transversal matter currents [22, 23] and a constant magnetic field [24,25], as well as to our newly developed approach to the problem of the neutrino quantum decoherence [26] and also to our recent proposal [27] for an experimental setup to observe coherent elastic neutrino-atom scattering (CEνAS) using electron antineutrinos from tritium decay and a liquid helium target that as we have estimated opens a new frontier in constraining the neutrino magnetic moment.
The discussed in the second part of the talk new results include two new effects that can be summarized as follows:
1) as it was shown for the first time in [22] neutrino spin and spin-flavor oscillations can be engendered by weak interactions of neutrinos with the medium in the case when there are the transversal matter currents; in [23] the quantum treatment of these phenomena is presented and different possibilities for the resonance amplification of oscillations are discussed, the neutrino Standard Model and non-standard interactions are accounted for;
2) within a new treatment [24] of the neutrino flavor, spin and spin-flavour oscillations in the presence of a constant magnetic field, which is based on the use of the exact neutrino stationary states in the magnetic field, it is shown that there is an interplay of neutrino oscillations on different frequencies. In particular: a) the amplitude of the flavour oscillations νLe↔ νLμ at the vacuum frequency is modulated by the magnetic field frequency μB , and b) the neutrino spin oscillation probability (without change of the neutrino flavour) exhibits the dependence on the neutrino energy and mass square difference Δm2 .
The discovered new phenomena in neutrino oscillations should be accounted for reinterpretation of results of already performed experiments on detection of astrophysical neutrino fluxes produced in astrophysical environments with strong magnetic fields and dense matter. These new neutrino oscillation phenomena are also of interest in view of future experiments on observations of supernova neutrino fluxes with large volume detectors like DUNE, JUNO and Hyper-Kamiokande.
Three other new results discussed in the concluding part of the talk are as follows:
3) a new theoretical framework, based on the quantum field theory of open systems applied to neutrinos, has been developed [26] to describe the neutrino evolution in external environments accounting for the effect of the neutrino quantum decoherence; we have used this approach to consider a new mechanism of the neutrino quantum decoherence engendered by the neutrino radiative decay to photons and dark photons in an astrophysical environment, the corresponding new constraints on the decoherence parameter have been obtained;
4) in [27] we have proposed an experimental setup to observe coherent elastic neutrino-atom scattering (CEνAS) using electron antineutrinos from tritium decay and a liquid helium target and shown that the sensitivity of this apparatus (when using 60 g of tritium) to a possible electron neutrino magnetic moment can be of order about 7×10−13μB at 90% C.L., that is more than one order of magnitude smaller than the current experimental limit;
5) in our most recent paper [28] we investigate effects of non-zero Dirac and Majorana CP violating phases on neutrinoantineutrino oscillations in a magnetic field of astrophysical environments; it is shown that in the presence of strong magnetic fields and dense matter, non-zero CP phases can induce new resonances in the oscillations channels ν e ↔ ν¯e, νe ↔ ν¯µ and νe ↔ ν¯τ ; the resonances can potentially lead to significant phenomena in neutrino oscillations accessible for observation in experiments; the detection of supernovae neutrino fluxes in the future experiments, such as JUNO, DUNE and Hyper-Kamiokande, can give an insight into the nature of CP violation and, consequently, provides a tool for distinguishing the Dirac or Majorana nature of neutrinos.
The best world experimental bounds on neutrino electromagnetic properties are confronted with the predictions of theories beyond the Standard Model. It is shown that studies of neutrino electromagnetic properties provide a powerful tool to probe physics beyond the Standard Model.
This research has been supported by the Interdisciplinary Scientific and Educational School of Moscow University “Fundamental and Applied Space Research” and also by the Russian Foundation for Basic Research under Grant No. 20-52-53022-GFEN-a.
References:
[1] A. Studenikin, Neutrino magnetic moment: A window to new physics, Nucl.Phys.B Proc.Suppl. 188 (2009) 220.
[2] C. Guinti and A. Studenikin, Neutrino electromagnetic interactions: A window to new physics, Rev. Mod. Phys. 87 (2015) 531-591.
[3] C. Giunti, K. Kouzakov, Y. F. Li, A. Lokhov, A. Studenikin, S. Zhou, Electromagnetic neutrinos in laboratory experiments and astrophysics, Annalen Phys. 528 (2016) 198.
[4] A. Studenikin, Neutrino electromagnetic interactions: A window to new physics - II,
PoS EPS-HEP2017 (2017) 137.[5] A. Studenikin, Electromagnetic neutrino properties: new constraints and new effects,
PoS ICHEP2020 (2021)180.[6] A. Beda, V. Brudanin, V. Egorov et al., The results of search for the neutrino magnetic
moment in GEMMA experiment , Adv. High Energy Phys. 2012 (2012) 350150.[7] M. Agostini et al (Borexino coll.), Limiting neutrino magnetic moments with Borexino Phase-II solar neutrino data, Phys. Rev. D 96 (2017) 091103.
[8] A. Studenikin, New bounds on neutrino electric millicharge from limits on neutrino magnetic moment, Europhys. Lett. 107 (2014) 21001.
[9] D. Papoulias, T. Kosmas, COHERENT constraints to conventional and exotic neutrino physics, Phys. Rev. D 97 (2018) 033003.
[10] M. Cadeddu, C. Giunti, K. Kouzakov, Y.F. Li, A. Studenikin, Y.Y. Zhang, Neutrino charge radii from COHERENT elastic neutrino-nucleus scattering, Phys. Rev. D 98 (2018) 113010.
[11] N. Viaux, M. Catelan, P. B. Stetson, G. G. Raffelt et al., Particle-physics constraints from the globular cluster M5: neutrino dipole moments, Astron. & Astrophys. 558 (2013) A12.
[12] S. Arceo-Díaz, K.-P. Schröder, K. Zuber and D. Jack, Constraint on the magnetic dipole moment of neutrinos by the tip-RGB luminosity in ω-Centauri, Astropart. Phys. 70 (2015) 1.
[13] A. Studenikin, I. Tokarev, Millicharged neutrino with anomalous magnetic moment in rotating magnetized matter, Nucl. Phys. B 884 (2014) 396-407.
[14] F. Capozzi and G. Raffelt, Axion and neutrino bounds improved with new calibrations of the tip of the red-giant branch using geometric distance determinations, Phys.Rev.D 102 (2020) 083007, arXiv:2007.03694v4 (24 Mar 2021).
[15] O. G. Miranda, D. K. Papoulias, M. Tórtola, J. W. F. Valle, XENON1T signal from transition neutrino magnetic moments , Phys.Lett. B 808 (2020) 135685.
[16] E. Aprile et al. [XENON], Observation of excess electronic recoil Events in XENON1T, Phys. Rev. D 102 (2020) 072004.
[17] K. Babu, S. Jana, M. Lindner, Large neutrino magnetic moments in the light of recent experiments, JHEP 2010 (2020) 040.
[18] V. Brdar, A. Greljo, J. Kopp, T. Opferkuch, The neutrino magnetic moment portal: Cosmology, astrophysics, and direct detection, JCAP01 (2021) 039.
[19] A. Parada, Constraints on neutrino electric millicharge from experiments of elastic neutrino-electron interaction and future experimental proposals involving coherent elastic neutrino-nucleus scattering, Adv.High Energy Phys. 2020 (2020) 5908904.
[20] K. Kouzakov, A. Studenikin, Electromagnetic properties of massive neutrinos in low-energy
elastic neutrino-electron scattering, Phys. Rev. D 95 (2017) 055013.[21] A. Grigoriev, A. Lokhov, A. Studenikin, A. Ternov, Spin light of neutrino in astrophysical environments, JCAP 1711 (2017) 024 (23 p.).
[22] A. Studenikin, Neutrinos in electromagnetic fields and moving media, Phys. At. Nucl. 67 (2004) 993.
[23] P. Pustoshny, A. Studenikin, Neutrino spin and spin-flavour oscillations in transversal
matter currents with standard and non-standard interactions, Phys. Rev. D 98 (2018) 113009.[24] A. Popov, A. Studenikin, Neutrino eigenstates and flavour, spin and spin-flavour oscillations in a constant magnetic field, Eur. Phys. J. C 79 (2019) 144.
[25] P. Kurashvili, K. Kouzakov, L. Chotorlishvili, A. Studenikin, Spin-flavor oscillations of ultrahigh-energy cosmic neutrinos in interstellar space: The role of neutrino magnetic moments”, Phys. Rev. D 96 (2017) 103017.
[26] K. Stankevich, A. Studenikin, Neutrino quantum decoherence engendered by neutrino radiative decay, Phys. Rev. D 101 (2020) 056004.
[27] M. Cadeddu, F. Dordei, C. Giunti, K. Kouzakov, E. Picciau, A. Studenikin, Potentialities of a low-energy detector based on 4He evaporation to observe atomic effects in coherent neutrino scattering and physics perspectives, Phys. Rev. D 100 (2019) 073014.
[28] A. Popov, A. Studenikin, Manifestations of non-zero Majorana CP violating phases in oscillations of supernova neutrinos, Phys. Rev. D 103 (2021) 115027.
Speaker: Alexander Studenikin (Moscow State University & JINR (Dubna)) -
17:40
First results of nuGeN experiment at Kalinin Nuclear Power Plant on coherent elastic neutrino-nucleus scattering 15m
The $\nu$GeN project is aimed to study neutrino scattering at the close vicinity of the reactor core of Kalinin Nuclear Power Plant (KNPP). Its main interests are connected with the detection of coherent elastic neutrino-nucleus scattering (CE$\nu$NS) and the search for the magnetic moment of neutrino. The experimental setup is constructed under reactor unit #3 of KNPP at a distance of about 10 m from the center of the 3.1 GW$_{th}$ core. In this way, we obtain an enormous antineutrino flux of more than 5x10$^{13}$ $\nu$/cm$^2$/s. Materials of the reactor surrounding provide about 50 m w.e. overburden, that serves as a good shielding against cosmic radiation. In combination with low ambient background, it gives us a unique opportunity to investigate antineutrino properties at the best location in the world. A special lifting mechanism allows moving the spectrometer towards to the reactor core changing the neutrino flux and thus suppressing main systematic errors caused by possible long-term instability and insufficient knowledge of neutrino flux. To detect signals from the neutrino scattering we use high-purity low-threshold germanium detectors surrounded by passive and active shieldings. A specially developed acquisition system allows suppressing noisy events. A detailed description of the experimental setup will be presented. In 2021 we finished optimization of the experimental setup and performed the first dedicated search of the CE$\nu$NS in the framework of our project by comparing the experimental spectra taken with regimes of reactor ON and OFF. The results of this analysis will be presented for the first time.
Speaker: Alexey Lubashevskiy (JINR) -
17:45
Detecting CEνNS and searching for new physics at reactor site with the CONUS experiment 15m
The detection of neutrinos through the coherent elastic neutrino-nucleus scattering (CEνNS) process opens a new window to study the fundamental properties of this elusive particle and to probe physics beyond the Standard Model. The CONUS experiment – operational since April 2018 – is located at a distance of 17m from the 3.9GWth core of the nuclear power plant Brokdorf (Germany). It aims to detect CEνNS in the fully coherent regime with four 1 kg HPGe point-contact detectors with a ~300eVee energy threshold.
The full spectral analysis of the first CONUS data set allows to set the current best limit on CEνNS with reactor antineutrinos and to deduce competitive limits on physics beyond the standard model, such as non-standard neutrino interactions or the neutrino magnetic moment. These new results will be presented in this talk. Special emphasis will be put on the strategy followed by the collaboration to further reduce the systematic uncertainties, in particular via a dedicated measurement of the ionization quenching factor of nuclear recoils in germanium.Speaker: Aurélie Bonhomme (MPIK Heidelberg) -
17:45
Exploring Coherent Elastic Neutrino-Nucleus Scattering of Reactor Neutrinos with the NUCLEUS Experiment 15m
Coherent elastic neutrino nucleus scattering (CE$\nu$NS) offers a unique way to study neutrino properties and to search for new physics beyond the Standard Model. The NUCLEUS experiment aims to measure CE$\nu$NS of reactor anti-neutrinos down to unprecedented low nuclear recoil energies. The novel gram-scale fiducial-volume cryogenic detectors feature an ultra-low energy threshold of $\sim$20 eV in nuclear recoil and a rise time of a few 100 $\mu$s which allows the operation above ground. The fiducialization of the detectors provides an effective discrimination of ambient $\gamma$- and surface backgrounds. Furthermore, the use of multiple targets promises a high physics potential.
The NUCLEUS experiment will be located at a new experimental site at the Chooz nuclear power plant in France, providing a high average anti-neutrino flux of $1.7\cdot10^{12}\,\bar{\nu_e}/(\text{s}\cdot\text{cm}^2)$. The commissioning of the full experimental setup is planned for 2022. This talk will review the physics potential of NUCLEUS and its current status.Speaker: Victoria Wagner (Technische Universität München) -
17:45
Gaseous detectors for Neutrino-nucleus coherent scattering at the ESS 15m
The recent detection of the coherent elastic neutrino-nucleus scattering (CEνNS )opens the possibil- ity to use neutrinos to explore physics beyond standard model with small size detectors. However, the CEνNS process generates signals at the few keV level, requiring of very sensitive detecting technologies for its detection.
The European Spallation Source (ESS) has been identified as an optimal source of low energy neutrinos offering an opportunity for a definitive exploration of all phenomenological applications of CEνNS. In this project I propose apply the high pressure xenon gas TPC technology to the detection of the CEνNS process at the ESS. This will require the development of very low-energy detectors and to improve the current knowledge of the quenching factor for nuclear recoils in xenon gas at keV energies. The major goal of this project is to build a 20 kg xenon gaseous detector and operate it at the ESS, such detector will provide more than 7,000 CEνNS events per year, overtaking the sensitivities of much larger detectors in current spallations sources.
In this talk I’ll present the advantages of the gaseous TPC technology to exploit the physics of the CEνNS process and the experimental program towards the construction and operation of a gaseous detector at the ESS.Speaker: Francesc Monrabal (DIPC) -
17:45
Low-energy reactor neutrino physics with the CONNIE experiment 15m
The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) uses fully depleted high-resistivity CCDs (charge coupled devices) with the aim of detecting the coherent elastic scattering of reactor antineutrinos with silicon nuclei and probing physics beyond the Standard Model. CONNIE is located at a distance of about 30 m from the core of the 3.8 GW Angra-2 nuclear reactor in Rio de Janeiro, Brazil. The experiment has been taking data since 2016 with a noise level of less than 2 electrons RMS and an active mass of 50 g. The analysis of the 2016-2018 data allowed us to set a 95% C.L. upper limit on the coherent scattering rate, which was used to place stringent constraints on simplified extensions of the Standard Model with light mediators. Currently, the experiment is operating with an improved readout and a lower energy threshold of 50 eV. We present the performance of the CONNIE experiment and new results of the blind analysis of 2019 data. We also report on the ongoing upgrade and the prospects for detecting the coherent elastic scattering of reactor neutrinos with the new detector technology of skipper CCDs.
Speaker: Irina Nasteva (Federal University of Rio de Janeiro (BR)) -
17:45
Physics reach of a Scintillating Bubble Chamber in CEvNS and its interplay with DM direct searches for extra vector mediators 15m
We will discuss the physics reach of a low threshold (100 eV) scintillating argon bubble chamber sensitive to Coherent Elastic neutrino-Nucleus Scattering (CEνNS) from reactor neutrinos. We will focus on the sensitivity for a light Z′ gauge boson mediator, and also review the complementarity of such experiment with DM direct detection experiments when the DM interacts with the light mediator.
Speaker: Eduardo Peinado (Instituto de Fisica UNAM) -
17:45
Physics reach of the ESSnuSB experiment 15m
ESSnuSB project is a design study for an upcoming accelerator-based neutrino oscillation experiment which will be driven by the ESS proton accelerator. The primary goal of this experiment is to measure the leptonic CP-violation phase with high precision at the second oscillation maximum. In this presentation, I will discuss the physics sensitivities of the proposed ESSnuSB experiment. In particular, I will discuss its capability to measure the leptonic CP phase, neutrino mass hierarchy, octant of the atmospheric mixing angle and the precision of atmospheric mixing angle and atmospheric mass squared difference. Further, I will discuss how the matter density can affect the CP measurement capability of ESSnuSB. In addition, I will also discuss the capability of this experiment to probe two of the new physics scenarios which are (i) light sterile neutrinos and (ii) invisible neutrino decay.
Speaker: Monojit Ghosh (Ruder Boskovic Institute) -
17:45
Status of Neutrino Elastic-scattering Observation with NaI(Tl) experiment (NEON) 15m
Coherent elastic neutrino-nucleus scattering (CEvNS) has important role for measuring neutrino properties and proving non-standard interactions.
Neutrino Elastic-scattering Observation with NaI(Tl) experiment (NEON) aims to detect this CEvNS in an NaI(Tl) crystal using reactor anti-electron neutrino at Hanbit nuclear power plant.
NEON detector which is installed 24 m distance away from the active reactor core consists of a 15 kg NaI(Tl) in the radiation shielding structures including a ~700 L liquid scintillator.
Data taking has started from December 2020 which includes 1 month reactor-off period.
We report the current status of NEON experiment in this talk.
Speaker: Insoo Lee (IBS)
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Discussion Panel Outreach and Education
Chair: Daniele de Gruttola
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17:10
Involving the new generations in particle physics endeavours 15m
Since 1984 the Italian groups of the Istituto Nazionale di Fisica Nucleare (INFN) and Italian Universities, collaborating with the DOE laboratory of Fermilab (US) have been running a two-month summer training program for Italian university students. While in the first year the program involved only four physics students of the University of Pisa, in the following years it was extended to engineering students. This extension was very successful and the engineering students have been since then extremely well accepted by the Fermilab Technical, Accelerator and Scientific Computing Division groups. Over the many years of its existence, this program has proven to be the most effective way to engage new students in Fermilab endeavors. Many students have extended their collaboration with Fermilab with their Master Thesis and PhD.
Since 2004 the program has been supported in part by DOE in the frame of an exchange agreement with INFN. An additional agreement for sharing support for engineers of the School of Advanced Studies of S.Anna (SSSA) of Pisa was established in 2007 between SSSA and Fermilab. In the frame of this program four SSSA students are supported each year. Over its 35 years of history, the program has grown in scope and size and has involved more than 500 Italian students from more than 20 Italian Universities, Since the program does not exclude appropriately selected non-italian students, a handful of students of European and non-European Universities were also accepted in the years.
Each intern is supervised by a Fermilab Mentor responsible for performing the training program. Training programs spanned from Tevatron, CMS, Muon (g-2), Mu2e and SBN design and experimental data analysis, development of particle detectors (silicon trackers, calorimeters, drift chambers, neutrino and dark matter detectors), design of electronic and accelerator components, development of infrastructures and software for tera-data handling, research on superconductive elements and on accelerating cavities, theory of particle accelerators.
Since 2010, within an extended program supported by the Italian Space Agency and the Italian National Institute of Astrophysics, a total of 30 students in physics, astrophysics and engineering have been hosted for two months in summer at US space science Research Institutes and laboratories.
In 2015 the University of Pisa included these programs within its own educational programs. Accordingly, Summer School students are enrolled at the University of Pisa for the duration of the internship and are identified and ensured as such. At the end of the internship the students are required to write summary reports on their achievements. After positive evaluation by a University Examining Board, interns are acknowledged 6 ECTS credits for their Diploma Supplement.
Information on student recruiting methods, on training programs of recent years and on final student`s evaluation process at Fermilab and at the University of Pisa will be given in the presentation.Speaker: Simone Donati (University of Pisa) -
17:25
Engaging the public with astrophysics virtual reality experiences 15m
Virtual reality (VR) technologies present exciting opportunities for astrophysics education and outreach. VR turns abstract concepts into experienceable phenomena and can increase interest and engagement with physics and astronomy. However, we still lack knowledge about how to maximise the benefits of VR when we use these technologies in public outreach programs. In this talk, we will present a case study of an astrophysics virtual reality experience at a science festival. To study the relationship between VR and visitor engagement, we developed a framework that comprises four aspects of visitor activity: immersion, facilitation, collaboration, and visualisation.This framework and our findings reveal important ways that VR supports visitor engagement at a science festival. We will finish the talk by giving recommendations for engaging the public with astrophysics both with and without VR.
Speaker: Magdalena Kersting (University of Oslo) -
17:40
The International Particle Physics Outreach Group - Reaching Across the Globe with Science 15m
The International Particle Physics Outreach Group (IPPOG) is a network of scientists, science educators and communication specialists working across the globe in informal science education and outreach for particle physics. The primary methodology adopted by IPPOG requires the direct involvement of scientists active in current research with education and communication specialists, in order to effectively develop and share best practices in outreach. IPPOG member activities include the International Particle Physics Masterclass programme, International Day of Women and Girls in Science, Worldwide Data Day, International Muon Week and International Cosmic Day organisation, and participation in activities ranging from public talks, festivals, exhibitions, teacher training, student competitions, and open days at local institutions. These independent activities, often carried out in a variety of languages to public with a variety of backgrounds, all serve to gain the public trust and to improve worldwide understanding and support of science. We present our vision of IPPOG as a strategic pillar of particle physics, fundamental research and evidence-based decision-making around the world.
Speaker: Steven Goldfarb (University of Michigan) -
17:45
Global Cosmic-Ray studies educational platform 15m
The International Particle Physics Group (IPPOG) is a global network active in informal education and outreach in particle physics and related research, including cosmic-ray and astro-particle physics. Since many years, IPPOG has been actively supporting the International Cosmic Day organized by DESY and the International Muon Week organized by Quarknet. In 2015 IPPOG started work on establishing a universal portal through which successful cosmic-ray study programmes can reach out to teachers and students around the world. This common web platform is being developed by IPPOG in the frame of its new IPPOG web pages. It will contain all information for schools interested in taking part in cosmic-ray experiments and analysing real data in classroom; also instructions about how to build, borrow, or purchase cosmic-ray detectors. The platform will also facilitate collaboration and exchanges between the experiments' project managers and advertising of related events.
Speaker: Barbora Bruant Gulejova (IPPOG / University of Bern / CERN) -
17:45
International masterclasses at IFIC: 17 years of particle physics for high school students 15m
The International Masterclasses "Hands on Particle Physics" is an initiative sponsored by the International Particle Physics Outreach Group and hosted by CERN, Fermilab and multiple research centers around the world. It aims to make particle physics knowledge available to high school-grade students and to create an environment where the students can feel how it is to work on an international collaboration. A central activity during the masterclasses is the rough analysis of real data from particle physics experiments by the students, usually by means of a simple software provided by the experiments. This allows several groups in different countries to carry out the same analysis on similar dates, and then the different groups can be gathered and their results can be compared and combined. The International Masterclasses have been running since the mid-2000s, and the Instituto de Física Corpuscular (IFIC) has participated in most of the editions. This talk will provide a review of our experience and the feedback we have gathered from students and teachers.
Speaker: Alberto Aparici (IFIC (CSIC-Univ Valencia)) -
17:45
Outreach and educational activities of the ALICE collaboration during the COVID pandemic 15m
With the onset of the COVID pandemic in 2020 all outreach and educational activities with in-person participation had to stop. The ALICE collaboration adapted to the new situation and continued reaching out to the public using the multitude of online tools and platforms available. We will focus here on two of our main outreach activities, virtual visits and masterclasses.
With the cancellation of all in-person visits to the underground installations, virtual visits became the only way to explore the experiment. ALICE had already been offering virtual visits for remote audiences with equipment installed in the ALICE Run Control Centre (ARC). We recently acquired dedicated mobile equipment for the virtual visits to the cavern and developed a scenario which includes both the cavern and the ARC as well as a Q&A session. In this way, visitors from many countries have the opportunity to interact with scientists and to see parts of the experiment that they would never be able to see during a real visit.
ALICE has been participating in the International Masterclasses (IMC) programme ever since measurements based on LHC data were introduced in it. The packages used had been developed by simplifying the ALICE event display and were based on ROOT. With the spreading of the COVID pandemic the 2020 IMC programme was interrupted. In 2021, with most activities taking place remotely, it was obvious that web-based versions were needed. The implementation of such versions allowed us to hold remote masterclasses for high-school students, thus ensuring the continuity of this important outreach activity of our community. In addition we reached new countries and also involved high-school teachers in this global effort.
Speaker: Despina Hatzifotiadou (INFN Bologna) -
17:45
Science Summaries: explaining LIGO-Virgo-KAGRA results to the global public 15m
LIGO, Virgo and KAGRA form the second-generation global network of gravitational wave detectors. From the first detection of the GW150914 binary black hole merger to the latest results from the recent O3 observing run, our observations are pushing frontiers in observational astrophysics. To continue inspiring the wider public with our findings, one key communications activity of the LVK collaborations are "science summaries" for each of our papers. These texts provide a less technical introduction to the topics covered in each paper and its key results, aimed at both students and interested lay readers. They are published at www.ligo.org and promoted through social media channels of the three collaborations. Before the pandemic, they also proved popular as printouts at science fairs, and we all hope we can return to that mode of outreach soon. As a global collaboration, over recent years we have also significantly stepped up our output of translations of these summaries, drawing on member scientists from across the globe, with materials published in a total of 23 different languages so far.
Speaker: David Keitel (Universitat de les Illes Balears) -
17:45
Spreading the space-time news: outreach and communication activities from the EGO-Virgo Collaboration 15m
The recent discoveries of Gravitational Wave (GW) signals have attracted a lot of interest from the general public and scientific colleagues. It is crucial to properly communicate the excitement of the emerging field of GW science to the society and have the potential to engage and educate new generations of future scientists.
The EGO-Virgo Collaboration is active in many outreach and communication fronts: from the fascinating complexity of the Advanced Virgo detector, together with its partners Advanced LIGO and KAGRA, to the physics behind the recent detections from this worldwide network of GW detectors. This talk will review the main outreach and communication activities carried out in this effort, including some specifically developed to cope for the pandemic: online and live remote visits and virtual tours to the EGO site, webinars, round table and online events, social media, collaboration with artists, sonifications, outreach and educational material translated in several languages and the development of exhibits for general public events.Speaker: Jerome Degallaix (LMA - IP2I) -
17:45
Teaching physics to school students from an Einsteinian standpoint 15m
In my presentation, I will discuss my study on middle school students’ understanding of Einsteinian physics with an emphasis on quantum physics that demonstrates the possibility of teaching physics from an Einsteinian standpoint. Firstly, I will show the age group dependence between students of year 7—10 by measuring students’ knowledge, and attitude towards physics. Secondly, I will demonstrate the possibility of combining physical models and analogies with digital learning resources for teaching Einsteinian physics. Finally, I will present a quantitative method for teaching the fundamental concepts of matter-wave interference and diffraction using simple devices called phasor wheels at the middle school level.
Speaker: Rahul Choudhary (The University of Western Australia) -
17:45
The Cosmic Ray Live Project @SNOLAB 15m
The Cosmic Ray Live project aims at building three muon detectors at SNOLAB. The detectors can measure muons in real time and show their trajectories. They would add significant data to the existing array and promote the international relationships that make science possible. One of SNOLAB’s missions is to inspire the next generation of innovators through strong educational outreach. This project aims to develop a tangible way for students and visitors to the Science North Museum to understand cosmic rays and why SNOLAB is located 2km underground. Our international partner at Laboratori Nazionali del Gran Sasso (LNGS) has perfected the build requirements and the accompanying smartphone app, which makes this science accessible to everyone in Canada. I will review them along with the current status of the project.
Speaker: Silvia Scorza (SNOLAB) -
17:45
The International Dark Matter Day in Argentina 15m
The International Dark Matter Day is celebrated worldwide on October 31 every year since 2017. In Argentina, it was organized for the first time in 2019 in an outreach effort coordinated by the ANDES deep underground laboratory. In 2019, we started a call for art students to propose an audiovisual piece on Dark Matter, asked about whether basic science was important for Argentina and coordinated the projection of the full dome "Phantom of the Universe" video in 4 digital planetarium in Argentina. In 2020, with no possibility of public event due to the pandemic, we repeated the audiovisual art call and organized a call for drawings and questions about Dark Matter for kids, reaching kids from Brazil and Mexico in addition to Argentina, among other activities.
In this presentation I will showcase some of the answers obtained to the calls and how these answers could be used to understand better how to communicate abstract topics such as Dark Matter to our society, taking into account the preconceptions about the topic.
Speaker: Maria Belen Lovino (CAB/UNRN) -
17:45
The Outreach and Education program of the Darkside experiment 15m
The Darkside experiment aims at the direct detection of Dark Matter in the form of Weakly Interacting Massive Particles (WIMPs). It is a 20-tonne (fiducial) argon dual-phase Time-Projection Chamber (TPC) that exploits the cryogenic SiPM technology to identify unambiguously the nuclear recoils induced by WIMPs. The experiment is being installed at the LNGS and will start operation around 2024.
The goal of the Outreach and Education program of Darkside is to disseminate the experiment activity through promotional videos and events addressed to the general public and students. One of our main activities is the DarkSide Masterclass, in which high school students become physicists for a day searching for WIMPs. After a few introductory lectures, the students analyze real data from the precursor DarkSide-50 experiment. Master degree students have access to a more complex version of this Masterclass. Six Masterclass events took place in the last two years, with the participation reaching 400 students in one event. In this talk, we will present the detailed Outreach and Education program of Darkside Collaboration.
Speaker: Bianca Bottino (Princeton University and INFN Genova) -
17:45
Undergroud muon flux measured by EEE students 15m
The Extreme Energy Events experiment (EEE) is an extended array of about 60 cosmic ray detectors installed in several Italian High Schools and in a few research laboratories. The EEE experiment has two main targets: a scientific and a dissemination. An array of telescopes made of three MRPC detectors is used to detect cosmic rays and perform physics measurements, such as studies on galactic cosmic rays variation, anisotropies or long distance correlations. The dissemination goal is achived by allowing students to actively participate in collaboration's activities, building telescopes, monitoring data acquisition, performing physics analysis under supervision of EEE researchers and presenting their results in monthly EEE collaboration meetings.
For field operations, the EEE collaboration developed a portable scintillator-based detector named Cosmic Box (CB). The CB allows students to perform cosmic ray counting measurements in various environments. CBs are made with two 15 x 15 x 1 cm scintillators read by two 3 x 3 cm$^2$ SIPMs operated in coincidence. Three CBs were deployed in Nuraxi Figus and Seruci coal mine to perform an underground measurement of the cosmic muon flux attenuation. 83 days were required to collect a total of 4260 events at the maximum depth of 512 m. High schools students from Sardinia and Lombardia were directly involved in all phases of the measurements. After a safety training, students helped in underground positioning of the detectors, DAQ configuring and data collection. Data were recorded in a SD memory card and eventually tranfered for the off-line analysis.
After presenting the EEE project, the contribution will be focused on the experimental set up and the measurement, reporting some preliminary results.
Speaker: Stefano Boi
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17:10
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18:00
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19:30
Poster session 2
Join the Gather.Town platform at:
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18:00
Germanium Detector Front-End Electronics for the LEGEND Experiment 15m
The question of whether the neutrino is identical to its anti-particle, i.e., a Majorana particle, is one of the most fundamental challenges in particle physics. This basic property is connected to the origin of the neutrino mass and could help explain the predominance of matter over antimatter in our Universe. Neutrinoless double-beta ($0\nu\beta\beta$) decay - a so-far unobserved radioactive transition - is the only known, feasible method to probe the Majorana nature of the neutrino in the laboratory. A discovery of $0\nu\beta\beta$ decay would unambiguously demonstrate that new lepton-number-violating physics exists and connect it to the origin of the neutrino mass.
The Large Enriched Germanium Experiment for Neutrinoless $\beta\beta$ Decay (LEGEND) is an ton-scale, $^{76}$Ge based, experimental program with discovery potential at half-lives beyond $10^{28}$ years.
In this contribution I will discuss the discrete, low-mass & low-background, germanium detector front-end (FE) electronics for the first 200-kg phase of the experiment (LEGEND-200), which is currently under construction at the Gran Sasso underground laboratory (Laboratori Nazionale del Gran Sasso, LNGS, Italy). In addition, I will present the R&D efforts on ASIC-based readout electronics for the ton-scale phase of the experiment (LEGEND-1000).This work is supported by the U.S. DOE, and the NSF, the LANL, ORNL and LBNL LDRD programs; the European ERC and Horizon programs; the German DFG, BMBF, and MPG; the Italian INFN; the Polish NCN and MNiSW; the Czech MEYS; the Slovak SRDA; the Swiss SNF; the UK STFC; the Russian RFBR; the Canadian NSERC and CFI; the LNGS and SURF facilities.
Speaker: Michael Willers (Technische Universität München) -
18:15
Rejecting Spallation Backgrounds in KamLAND-Zen with KamNet 15m
KamLAND-Zen is a liquid scintillator detector searching for neutrinoless double beta decay of Xenon-136. Recently, KamLAND-Zen set world-leading limits on this elusive process. One of the primary challenges of this search is the rejection of backgrounds from radioactive isotopes introduced by cosmic-ray spallation. We developed a state-of-the-art neural network classifier, called KamNet, to reject background events and improve detection sensitivity. However, as we rely more heavily on deep neural networks to play key roles in data analysis, it becomes increasingly important to understand exactly how they work. Here, we take a look at KamNet through the lens of network interpretability. Using Monte Carlo (MC) simulations and experimental data, we present the results of recent studies of the origin of KamNet's rejection power. We find that KamNet has the ability to discern multi-vertex events (one or more gammas in addition to a beta) from single-vertex beta events (only betas). This beta vs beta+gamma discrimination is used to help us ascertain spallation background levels. KamNet's rejection performance for key spallation backgrounds will be presented and we discuss how KamNet can inform us about the types of backgrounds it's rejecting.
Speaker: Hasung Song (Boston University) -
18:30
New measurement of double beta decays to excited states in the CUPID-Mo experiment 15m
CUPID-Mo, located at the Laboratoire Souterrain de Modane, in France was a demonstrator for CUPID, a next generation search for $0 \nu \beta \beta$ in $^{100}$Mo. It consisted of an array of 20 Li$_2$MoO$_4$ bolometers and 20 Ge light detectors for particle ID. It has demonstrated excellent crystal radio-purity ($^{238}$U/$ ^{232}$Th chains $0.3 - 1$ $\mathrm{\mu Bq/kg}$ for relevant isotopes), $\alpha$, $\beta/\gamma$ particle discrimination ($>99.9\%$), and energy resolution ($\sim 7 \ \mathrm{keV}$ FWHM at $2615$ $\mathrm{keV}$). This performance allowed CUPID-Mo to place the leading limit on the half life of $0 \nu \beta \beta$ in $^{100}$Mo of $T_{1/2}^{0 \nu}>1.5 \cdot 10^{24}$\,yr despite a very modest $2.16$ kg-yr exposure.
In this work we present the results from the search for double beta decays of $^{100}$Mo to excited states of $^{100}$Ru. Precision measurement of the $2\nu\beta\beta$ decay can help constrain nuclear models which are needed to interpret $0\nu\beta\beta$ results as a limit on the neutrino mass.
In these decays, the electrons are accompanied by one or more de-excitation gamma quanta. Multi-site events provide a very clear experimental spectrum technique to search for these decays and separate them from possible background sources.
Finally, we demonstrate how the analysis techniques we have developed could be employed by the next generation experiment CUPID to reach an unprecedented sensitivity to decays to excited states and other rare processes.Speaker: Toby Dixon (UC Berkeley) -
18:45
Optimizing the time resolution of cryogenic calorimeters with NTDs: the CALIPSO project 15m
The CALIPSO project deals with the development and optimization of low temperature (~10 mK) solid state detectors. The goal of the project is to propose new strategies for improving the time resolution of cryogenic scintillating calorimeters, read with NTD thermistors. We will test new NTD-detector coupling techniques and optimize the NTD operation to make the response faster. In parallel, we will work on improving the scintillation light yield for different crystals at low temperatures. Rare events physics experiments utilizing the NTD-detector technology on a large scale, such as the ones searching for the neutrinoless double beta decay (CUORE; CUPID), could profit from the results of this project.
Speaker: Irene Nutini (Università e Sezione INFN di Milano Bicocca) -
19:15
A comparative study of Dirac and Majoarana ultrahigh-energy neutrino oscillations in an interstellar magnetic field 15m
One of the important developments in the field of neutrino astrophysics is a search for ultrahigh-energy (UHE) cosmic neutrinos (even above PeV–EeV energies), which are believed to be produced by reactions of UHE cosmic rays composed of protons and nuclei. These neutrinos can be detected with neutrino telescopes, such as IceCube, ANTARES, Baikal-GVD, and KM3NeT, and are expected to provide information about cosmic accelerators and the high-energy, distant universe. One of the major advantages of exploring the UHE neutrinos as astrophysical messengers is supposed to be their ability, as opposed to the case of charged particles, of traveling in straight lines in magnetic fields in space. This feature allows one to point back their intensively energetic sources in the sky, including active galactic nuclei, supernovae and associated phenomena like γ-ray bursts, and compact objects such as black holes and neutron stars. At the same time, even though neutrinos are generally believed to be electrically neutral particles they can still have nonzero magnetic moments [1]. This means that the propagation of the UHE cosmic neutrinos can be influenced by interstellar magnetic fields due to the effect of spin oscillations [2]. In this contribution we examine the UHE neutrino propagations in interstellar space in the Dirac and Majorana cases. Employing the two-neutrino mixing approximation and using the most stringent astrophysical constraints on neutrino magnetic moments, we show that both the flavor and the spin oscillations of the Dirac and Majorana neutrinos exhibit qualitatively different behaviors in an interstellar magnetic field for neutrino-energy values characteristic of, respectively, the cosmogenic neutrinos, the Greisen-Zatsepin-Kuz’min (GZK) cutoff, and well above the cutoff.
The work is supported by the Interdisciplinary Scientific and Educational School of Moscow State University "Fundamental and Applied Space Research" and by the Russian Foundation for Basic Research under grant no. 20-52-53022-GFEN-A.
References
[1] C. Giunti and A. Studenikin, Neutrino electromagnetic interactions: A window to new physics, Rev. Mod. Phys. 87, 531 (2015), arXiv:1403.6344 [hep-ph]
[2] P. Kurashvili, K.A. Kouzakov, L. Chtorlishvili, and A.I. Studenikin, Spin-flavor oscillations of ultrahigh-energy cosmic neutrinos in interstellar space: The role of neutrino magnetic moments, Phys. Rev. D 96, 103017 (2017), arXiv:1711.04303 [hep-ph].Speaker: Konstantin Kouzakov (Moscow State University) -
19:15
A Geant4-based model for the TRISTAN detector 15m
The TRISTAN project is the upgrade of the KATRIN experiment that aims at searching for sterile neutrino with mass in the keV range through precise measurements of the entire Tritium $\beta$-spectrum.
In order to achieve this goal, the current KATRIN detector must be replaced with a multipixel detector based on Silicon Drift Detectors (SDDs). SDDs, with their excellent energy resolution and capability of sustaining high count rates, are commonly used for X-ray spectroscopy. Electron spectroscopy is a relatively novel application, it is therefore necessary to characterize SDDs response to electrons.
To do this we have started illuminating a single SDD with a monochromatic electron beam coming from a SEM (Scanning Electron Microscope), acquiring data at different energies and angles. We have then realized a Geant4 simulation of the electron interaction with Silicon, and we have processed the output with an empirical model that describes SDDs dead-layer and depth-dependent charge collection efficiency. By fitting data with simulations at different energies and angles we have estimated the free parameters of this empirical model.
We have later realized backscattering measurements using two SDDs, one of which operated as a target. We have written a Geant4 simulation of the whole setup and processed its output with the best empirical model found with SEM data. The result of this operation is a satisfactory description of both the spectra of the two single detectors and the spectrum obtained by summing the energies released in the two SDDs for coincident events.
Deriving such a model for electron interactions with an SDD is mandatory in order to accurately reconstruct the continuous $\beta$-spectrum that will be measured in TRISTAN. Moreover, we expect that the detector response will be one of the main TRISTAN systematics, therefore the precise estimation of its parameters allows to preserve an high sensitivity in the search for the sterile neutrino.Speaker: Andrea Nava (University of Milano-Bicocca) -
19:15
Astroparticle physics obtaining more attention from a new type of audience 15m
The high-energy physics is experiencing an interesting twist of events as some basic principles related to cosmic-rays and atmospheric production of cascading earthbound particles appear becoming more mainstream, at least in other sciences. We offer a few examples to support the point. First, the corresponding author of this work is a geologist by education and yet in the process to cross the barrier between two branches of science that have not traditionally crossed the paths too often (the radionuclide dating been one of the major exceptions). This particular personal journey may not yet be a tip of an iceberg, but it is, at the very least, an example of a new tendency of cross-pollination between disciplines. In this case, the driving force is muons and muography, the rapidly evolving application of muons in as wide range of disciplines as archaeology, engineering, and earth sciences (including planetology and research of asteroids).
Muography is a novel geophysical imaging and monitoring method for density contrasts and temporal density changes in solid and liquid materials. It is based on the differential attenuation of atmospheric muons in various directions in the material between the radiation source (air showers in the atmosphere) and the detector. The latter can be installed on ground or underground. Characterization of material densities can obtain many forms and it can be carried out with many types of gaseous, scintillation, and nuclear emulsion detectors. These include drift chambers, micro-mesh gaseous structures, resistive plate chambers, multi-wire proportional chambers, scintillation detectors, and Cherenkov telescopes. Some detectors are mobile, some transportable, and some stationary. Some detectors are used in stable conditions, whereas in some cases the application dictates that the detector must be robust and of high endurance. The latter is especially true for the long-term open-air or underground monitoring campaigns. Most of the varied detector types can be deployed in multiple environments (e.g., within buildings, on the surface of the earth, caves, and tunnels), some even underwater (e.g., borehole detectors). The materials, too, can be of many types and origins (e.g., a pyramid, historical building, engineered structure, an active, dormant or fossil volcano, karst cave, a soil bed or bedrock formation, and an open pit or underground mine). Most importantly, at least regarding the current topic, the researchers themselves can have backgrounds that differ from one another drastically (an archaeologist, volcanologist, architect, geologist, geophysicist, mineral explorationist, mining engineer, etc.).
It is the above cross-pollination between the different disciplines that establishes muography not only a highly multidisciplinary but also a cross-disciplinary field of research. It also aids to enlarge and widen the audience base of astroparticle physics. Even if this new research may not automatically be of great interest to astroparticle physicists, it is likely fruitful in the long run as some research topics are hard to carry out without specialized skills and expertise in these other disciplines (e.g., muon propagation and energy loss in real-world rocks). In the short term, however, the best value proposition for the astroparticle physicists is that their own research is becoming increasingly referenced by authors who are non-physicists and in journals that are not necessarily followed by astroparticle physicists. It is also likely that this new pool of researchers increases the total reference counts of some astroparticle physics publications.
We will provide more examples of the development of muography and the expanding distribution of astroparticle physics amongst the other disciplines in our longer, follow-up work.
Speaker: Marko Holma (Muon Solutions Oy, Finland) -
19:15
At what local temperature does xenon bubble? 15m
During the past decades experiments using liquid xenon as a detector material have grown rapidly in the fields of dark matter and neutrino searches. During the scale up of such detectors there is a big push to move the electronics closer to the detectors which are submerged in cryogenic noble gases. One such example is the development of ASICs operating in liquid xenon for the amplification and digitization of charge and light signals. A big question is how much heat can be generated before these chips creates bubbles (nucleate boiling) in the xenon. Such bubbles could create high-voltage, pressure and electronic noise problems within a detector. We report the first precision measurement of the superheat temperature required for bubble nucleation in liquid xenon of Δ Twall,ONB = (16.9±0.5) K and Δ Twall,ONB = (19.2+0.4−1.1) K at pressures of P = (0.98±0.02) bar and P = (1.32+0.05−0.01) bar, respectively. In this talk we will present the results together with the video material of creating bubbles in liquid xenon.
Speaker: P.A. (Sander) Breur (SLAC national accelerator laboratory) -
19:15
Background model of the ANAIS-112 dark matter experiment 15m
The ANAIS-112 experiment is intended to test the observation of an annual modulation signal by the DAMA/LIBRA experiment using 112.5 kg of NaI(Tl) detectors operated in the Canfranc Underground Laboratory (Spain). Data taking is going on since August, 2017 and annual modulation results from the analysis of three years of data have been presented, being compatible with the absence of modulation.
A complete study of the ANAIS-112 detector background was carried out before unblinding data for the first modulation analysis using the first year of data. A background model was developed for each detector from the direct measurement of primordial and cosmogenic activity in crystals and other components and Monte Carlo simulation. The knowledge of some cosmogenic isotopes activities considered in this model has been improved by profiting from the large accumulated three-year exposure, and using only events outside the Region of Interest, has led to a better explanation of the detector background time evolution. These background studies have been relevant to understand the different background components and to predict sensitivity as well as to model the time evolution considered in the annual modulation analysis.
Here, the ANAIS-112 background model will be firstly described; then, considering different analysis conditions and energy ranges, the comparison of model and measurements for energy spectra and counting rate time evolution for three years of data will be discussed.
Speaker: Susana Cebrian (Universidad de Zaragoza) -
19:15
Behaviour of the lateral shower age of cosmic ray extensive air showers 15m
Some simple arguments are introduced for a possible explanation of the behaviour of the lateral shower age of proton-initiated showers. The corresponding analytical treatment based on the proposed argument is then illustrated. Using the Monte Carlo simulation code CORSIKA, we have validated how the different characteristics associated with the lateral shower age predicted in the present analytical parametrization, can be understood. The lateral shower age of a proton-initiated shower and its correlations with the lateral shower ages of electron- and neutral pion-initiated showers supports the idea that the result of superposition of several electromagnetic sub-showers initiated by neutral pions might produce the lateral density distribution of electrons of a proton initiated shower. It is also noticed with the simulated data that the stated feature still persists even in the local shower age representation.
Speaker: Rajat K Dey (University of North Bengal) -
19:15
Characterization of the JUNO Large-PMT readout electronics 15m
The Jiangmen Underground Neutrino Observatory (JUNO) is a neutrino medium baseline experiment under construction in southern China, expecting to begin data taking in 2023. The experiment has been proposed with the main goals of determining the neutrino mass ordering and measure three oscillation parameters with sub-percent precision. To reach these goals, JUNO is located about 53 km from two nuclear power plants and will detect electron antineutrinos from reactors through inverse beta decay. Furthermore, an unprecedented energy resolution of 3% at 1 MeV is required. The JUNO detector consists of 20 kton of liquid scintillator (LS) contained in a 17.7 m radius acrylic vessel, which is instrumented with a system of about 18000 20-inch Large-PMTs and 25600 3-inch small-PMTs, with a total photocoverage greater than 75%.
The signal from the Large-PMTs is processed by the JUNO electronics system, which can be divided into two main parts: the front-end electronics, placed underwater, consisting of a Global Central Unit (GCU); and the back-end electronics, outside water, consisting of DAQ and trigger. Each GCU reads three Large-PMTs and has the main tasks of performing the analog-to-digital conversion of the signals, generating a local trigger to be sent to the global trigger, reconstructing the charge, tagging events with a timestamp, and temporarily storing data in the local FPGA memory before transferring it to DAQ upon a global trigger request. The poster will mainly focus on the description of the underwater electronics for the Large-PMTs. Results from tests on a small setup with 13 GCUs at Laboratori Nazionali di Legnaro, Italy, as well as from the upcoming integration test with 700 GCUs in China, will be presented.
Speaker: Beatrice Jelmini (Università degli Studi di Padova & INFN Padova) -
19:15
Collective neutrino oscillations in moving and polarized matter 15m
We study neutrino flux evolution in an extreme astrophysical environment peculiar to supernovae accounting for the collective effects and effects of an arbitrarily moving and polarized media and a strong magnetic field. The effect of the transversally moving matter on the flavour and spin-flavour oscillations in a magnetic field was considered in [1-3]. In the present paper we further develop the quantum theory of neutrino flavour and spin-flavour oscillations in moving magnetized matter with a special focus on the possible effects of the transversal matter polarization. Both the cases of Dirac and Majorana neutrinos are considered. In addition, we also account for the superimposed effect of the collective neutrino oscillations and discuss possible spectral splits of the final neutrino fluxes that can arise due to flavour and spin-flavour oscillations in this case.
This research has been supported by the Interdisciplinary Scientific and Educational School of Moscow University “Fundamental and Applied Space Research” and also by the Russian Foundation for Basic Research under Grant No. 20-52-53022-GFEN-a. The work of KS is also supported by the RFBR under grant No. 20-32-90107 and by the “BASIS” Foundation No. 20-2-2-3-1.
[1] A. Studenikin, Neutrinos in electromagnetic fields and moving media, Phys.Atom.Nucl. 67 (2004) 993-1002 (Yad.Fiz. 67 (2004) 1014-1024).
[2] P. Pustoshny, A. Studenikin, Neutrino spin and spin-flavour oscillations in transversal matter currents with standard and non-standard interactions, Phys. Rev. D 98 (2018) 113009.
[3] Y.-F.Li, K.Kouzakov, V.Shakhov, K.Stankevich, A.Studenikin, Z.Yuan, Interplay of neutrino flavor, spin and collective oscillations in supernovae, PoS ICHEP2020 (2021) 206.Speaker: Yufeng Li (Institute of High Energy Physics) -
19:15
Core-collapse simulation of SN 1987A binary progenitor and its multimessenger signals 15m
We perform a three-dimensional self-consistent core-collapse supernova simulation using a binary evolution progenitor model of SN 1987A by Urushibara et al. (2018). This progenitor model is based on a slow-merger of 14 and 9 solar-mass stars and it satisfies most of the observational constraints such as red-to-blue evolution, lifetime, total mass and position in the Hertzsprung-Russell diagram at collapse, and chemical anomalies. We find that this progenitor model successfully present explosion and leave a 1.53 solar-mass neutron star with a kick velocity of 70 km/s and a spin period of 0.1 s. Assuming a detector sensitivity of Kamiokande-II and the distance to the supernova of 51 kpc, we obtain 16 neutrino detection events in one second. Some characteristic modes in its gravitational wave signal will also be discussed in our presentation.
Speaker: Ko Nakamura (Fukuoka University) -
19:15
Cosmic activation of CRESST’s CaWO4 crystals 15m
The CRESST experiment searches for dark matter induced nuclear recoils inside $\rm CaWO_4$ based cryogenic calorimeters at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. To reliably identify a potential signal, a precise understanding of its background budget is crucial.
A potentially important background category are “cosmogenics”: radionuclides produced via interactions with cosmic rays, mainly during the crystal production at surface facilities. Albeit $\rm CaWO_4$ is a well-established calorimetric material, no systematic study of its susceptibility for cosmic activation existed so far.
In this contribution, we will first report the exposure profile of CRESST’s in-house grown $\rm CaWO_4$ crystals to cosmic rays. Then we will identify the most prominent cosmogenics via ACTIVIA calculations. Afterwards we discuss the expected background spectrum based on Geant4 simulations and compare it to measurements. Finally, we give an outlook on ongoing cross-checks with alternative activation codes.
Speaker: Holger Kluck (Vienna Univ of Technology) -
19:15
Cosmological implications of EW vacuum instability: constraints on the Higgs-curvature coupling from inflation 15m
The current experimentally measured parameters of the Standard Model (SM) suggest that our Universe lies in a metastable electroweak vacuum, where the Higgs field is prone to vacuum decay to a lower state with catastrophic consequences. Our measurements dictate that such an event has not taken place yet, despite the many different mechanisms that could have triggered it in our past light-cone. The focus of our work has been to calculate the probability of the false vacuum to decay during the period of inflation and use it to constrain the last unknown renormalisable SM parameter $\xi$, which couples the Higgs field with space-time curvature. More specifically, we derived lower $\xi$-bounds from vacuum stability in three inflationary models: quadratic and quartic chaotic inflation, and Starobinsky-like power-law inflation. We also took the time-dependence of the Hubble rate into account both in the geometry of our past light-cone and in the Higgs effective potential, which is approximated with three-loop renormalisation group improvement supplemented with one-loop curvature corrections. Finally, an overview of some preliminary results regarding this calculation in the context of $R^2$-inflation will be given .
Speaker: Andreas Mantziris (Imperial College London) -
19:15
Cosmology of modified Chaplygin gas under the purview of f(T) gravity 15m
In this work, we investigate the cosmological application of modified Chaplygin gas
(MCG) interacting with pressureless dark matter (DM) in the f(T) modified gravity
framework, where T is the torsion scalar in teleparallelism. The interaction term has
been chosen proportional to the MCG density with positive coupling constant. In the
Einstein general relativity (GR) framework, the interacting MCG has been found to
have equation of state (EoS) parameter behaving like quintessence. However, the f(T)
gravity reconstructed via the interacting MCG has been found to have EoS crossing
the phantom boundary of −1. Thus, one can generate a quintom-like EoS from an
interacting MCG model in flat universe in the modified gravity cosmology framework.
The reconstructed f(T) model has been found to interpolate between dust and ΛCDM.
Stability of the reconstructed f(T) has been investigated and it has been observed
that the model is stable against gravitational perturbation. Cosmological evolution of
primordial perturbations has also been investigated and the self-interacting potential
has been found to increase with cosmic time and the squared speed of sound has been
found to be non-negative.Speaker: Surajit Chattopadhyay (Dept of Mathematics, Amity University, Kolkata) -
19:15
Dark matter Axion search with riNg Cavity Experiment DANCE: Design and development of auxiliary cavity for simultaneous resonance of linear polarizations 15m
Axion-like particles (ALPs) are undiscovered pseudo-scalar particles that are candidates for ultralight dark matter. ALPs interact with photons slightly and cause the rotational oscillation of linearly polarized light. DANCE searches for ALP dark matter by amplifying the rotational oscillation with a bow-tie ring cavity.
The sensitivity of the current prototype experiment DANCE Act-1 is degraded by around 3 orders of magnitude due to the resonant frequency difference between s- and p- polarizations in the bow-tie ring cavity.The simultaneous resonance of linear polarizations is necessary to amplify both the carrier field and the ALP signal, and to achieve the design sensitivity.
In order to tune the resonant frequency difference, a method of introducing an auxiliary cavity was proposed. We are now introducing the idea of the auxiliary cavity to DANCE Act-1. In this conference, we will report on the design, the control scheme and the current status of the auxiliary cavity of DANCE Act-1.Speaker: Hiroki Fujimoto (Department of Physics, University of Tokyo) -
19:15
Density functional theory calculates general crystal responses for electron-dark matter interactions in silicon and germanium 15m
We test the influence of the detailed description of the electronic structure in crystalline silicon and germanium on the resulting calculated response of the electrons to general dark matter interactions.
We show that if the dark matter interaction energy reaches a threshold of about 30 eV, electron excitations from tightly-bound germanium 3$d$ states become important and since these are very narrow, they suffer from incorrect electron self-interaction in the local density approximation to density functional theory. We address this problem by introducing a Hubbard U-correction term that corrects the energy of these bands and restores them to the experimentally observed value. We then calculate the scattering rates coming from general crystal responses and put constraints on current experiments that are using silicon and germanium targets.Speaker: Marek Matas (ETH Zurich) -
19:15
Detection of Core-Collapse Supernova Neutrino at JUNO 15m
JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses
20kton liquid scintillator as a target, which enables it to detect supernova burst neutrinos of
large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova
neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be
detected by JUNO via several interaction channels, including inverse beta decay (IBD), elastic
scattering on electron and proton, etc. Among them, IBD events makes it possible to get the
directional information of CCSN even in a liquid scintillator detector. The real-time monitoring
systems for the next CCSN based on FPGA and DAQ are under development in JUNO, which
allows prompt alert and trigger-less data acquisition of CCSN eventsSpeaker: Xin Huang (IHEP) -
19:15
Development of high-sensitivity radon detector in water for neutrino physics 15m
Radon contamination in water causes serious background for low energy physics in Super-Kamiokande experiment, especially, search for distortions of the solar neutrino energy spectrum induced by the MSW effect.
Continuous monitoring of radon concentration in water with < 1 mBq/m3 level is indispensable to reveal remaining source of radon including its time evolution and lower energy threshold (currently 3.5 MeV kinetic energy).
We are now developing low background and high sensitivity radon detector by screening materials of the detector and maximizing the detection efficiency.
In this poster, development of high-sensitivity radon detector for water with continuous measurement is presented.Speaker: Atsushi Takeda (ICRR, Univ. of Tokyo) -
19:15
Diffusion of density inhomogeneities in the early universe 15m
Density inhomogeneities can be generated very early in the universe. They are one of the reasons for all the large-scale structures in the early universe. Density inhomogeneities play an important role in nucleosynthesis calculations and affect the phase transition dynamics. These inhomogeneities decay by particle diffusion in the early universe. We have studied the decay starting from the electroweak phase transition up to the starting of the nucleosynthesis era. We study the decay of these inhomogeneities in the early universe with and without considering the expansion of the universe. We calculate the interaction cross-section of the quarks with the neutrinos, the electrons, and the muons and obtain the diffusion coefficients. We find that the expansion of the universe causes the inhomogeneities to decay at a faster rate. We find that the inhomogeneities generated at the electroweak epoch have very low amplitudes at the time of the quark hadron phase transition. So unless inhomogeneities are generated with a very high amplitude, they will have no effect on the quark hadron phase transition. In the hadronic phase, we have considered the interaction of neutron, proton, electron, and muon. We include the interaction of the muons with the neutrons and the protons till 100 MeV. We also find that large density inhomogeneities generated during the quark hadron transition with sizes of the order of 1 km must have amplitudes greater than 10^5 times the background density to survive up to the nucleosynthesis epoch in an expanding universe.
Speaker: Sovan Sau (University of Hyderabad) -
19:15
Effects of nonzero Majorana CP phases on oscillations of supernova neutrinos 15m
We study the effects of nonzero Dirac and Majorana CP-violating phases in neutrino oscillations in a magnetic field of astrophysical environments. It is shown that in the presence of strong magnetic fields and dense matter, nonzero CP phases can induce new resonances, particularly in the oscillations channels $\nu_e \leftrightarrow \bar{\nu}_e$, $\nu_e \leftrightarrow \bar{\nu}_\mu$ and $\nu_e \leftrightarrow \bar{\nu}_{\tau}$. We show that neutrino-antineutrino oscillations can affect the $\bar{\nu}_e$/$\nu_e$ ratio for neutrinos coming from the supernovae explosion, provided that the Majorana CP-violation phases are nonzero. The detection of supernovae neutrino fluxes in the future experiments, such as JUNO, DUNE and Hyper-Kamiokande, can give an insight into the nature of CP violation and, consequently, provides a tool for distinguishing the Dirac or Majorana nature of neutrinos.
This research has been supported by the Interdisciplinary Scientific and Educational School of Moscow University “Fundamental and Applied Space Research” and also by the Russian Foundation for Basic Research under Grant No. 20-52-53022-GFEN-a. The work of A. P. has been supported by the Foundation for the Advancement of Theoretical Physics and Mathematics “BASIS” under Grant No. 19-2-6-209-1.
References
[1] A. Popov, A. Studenikin, “Manifestations of nonzero Majorana CP-violating phases in
oscillations of supernova neutrinos", Phys.Rev.D 103 (2021) 11, 115027Speaker: Artem Popov (Lomonosov Moscow State University) -
19:15
Energy Response Model for JUNO Experiment 15m
Energy Response Model for JUNO Experiment
Miao Yu, on behalf of JUNO collaboration
The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose neutrino experiment with 20000 ton liquid scintillator (LS) detector under civil construction. The primary physics goal for JUNO is to determine the neutrino mass ordering by precisely measuring the fine oscillation pattern of reactor neutrinos at around 53 km baseline. Antineutrinos emitted by nuclear reactors are detected by inverse beta decay (IBD) interaction $\bar\nu_e + p→ e^+ + n$ where the positron carries most fraction of neutrino energy. To precisely construct incoming neutrino energy spectrum, it’s vital to have a better understanding for positron energy response (e.g. nonlinearity and resolution) in LS. While the common calibration sources are almost gamma sources, it is required to develop a calibration-based energy response model for positrons with the help of calibration data. In this poster, a unified model to describe both nonlinearity and energy resolution is presented, and the effects from scintillation light and Cherenkov light are studied separately in detail. Also, possible disentanglement between scintillation and Cherenkov light contributions in energy response based on feasible external measurements are discussed for better model constraints.
Speaker: Miao Yu (Institution of High Energy Physics, China) -
19:15
Evaluation of event reconstruction with small-scale water Cherenkov detectors 15m
The Hyper-Kamiokande experiment is planned to start in 2027 aiming for precise measurement of neutrino oscillation using J-PARC neutrino beam including the search for CP violation. Hyper-Kamiokande detector is a 260 kiloton water Cherenkov detector and has large statical power, requiring systematic uncertainty at the 1% level or less on neutrino oscillation measurements. For this purpose, a new 1 kiloton scale Intermediate Water Cherenkov Detector (IWCD), which is based on the same detection principle as Hyper-Kamiokande is proposed to measure the neutrino flux and interaction cross section near the generation point of the neutrino beam before oscillation. The goal of IWCD is to reduce the systematic uncertainty in the long baseline neutrino oscillation measurement of the Hyper-Kamiokande experiment. Water Cherenkov Test Experiment (WCTE) is a 50 ton scale water Cherenkov detector and currently under preparation to evaluate the performance of IWCD. WCTE will use new photosensor technologies such as multi-PMT modules and will study the response of small water Cherenkov detectors to electron, muon, and hadron beams at CERN.
In this poster, we will present the performance of event reconstruction with the IWCD and WCTE detectors using the simulation.Speaker: Koki Yamauchi (Tokyo University of Science) -
19:15
Evaluation of neutron tagging performance in the Hyper-Kamiokande experiment 15m
Hyper-Kamiokande (HK) is a next generation multi-purpose neutrino and nucleon-decay experiment scheduled to begin operation in 2027. The experimental setup of HK will consist of the neutrino beam line and a suite of near detectors at J-PARC, and a far detector of the same name, HK. The far detector HK, filled with 260 kton of pure water is able to detect a Cherenkov light from the relativistic charged particles produced in the (anti)neutrino interactions. To distinguish neutrino and antineutrino interactions in HK, a neutron signal can be used. This is especially important in the Diffused Supernovae Neutrinos Background search, which is one of the physics targets of HK. Using neutron signals allows HK to highly suppress background events and to improve the signal sensitivity. Furthermore, the neutron tagging largely reduces neutrino-induced backgrounds with neutrons in the nucleon decay search where nucleon decays rarely accompany neutrons. In the pure water detector, the generated neutron is thermalized in water and captured by a hydrogen nucleus. The hydrogen nucleus emits a 2.2 MeV gamma-ray that is seen as a delayed signal of the prompt Cherenkov events eventually. In this study, we simulated the neutron signal and one of the dominant backgrounds, created by Rn, which might mimic the neutron signals, and evaluated tagging efficiency in HK. The neutron tagging algorithm and the results will be presented.
Speaker: Shota Izumiyama (Tokyo Institute of Technology) -
19:15
Event reconstruction performance with new retro-reflector based designs for water Cherenkov detectors 15m
We have proposed the possibility of a cost-efficient way to improve the detector performance for water Cherenkov detectors, by reflecting the usually lost light falling between photo-detectors onto the other side of the tank with retro-reflectors. Using a detector simulation based on optical measurements of retro-reflectors, we developed a convolutional neural network based reconstruction algorithm. Here we report on the reconstruction performance for ring events in the energy scale expected for atmospheric and accelerator neutrinos under various candidate detector configurations.
Speaker: Lukas Berns (Tokyo Institute of Technology) -
19:15
First results from the ARTIE experiment 15m
A measurement of the transmission coefficient for neutrons through a thick (~3 atoms/b) liquid natural argon target in the energy range 30-70 keV was performed by the Argon Resonance Transmission Interaction Experiment (ARTIE) using a time of flight neutron beam at Los Alamos National Laboratory.
In this energy range theory predicts an anti-resonance in the $^{40}$Ar cross section near 57 keV, but the existing data, coming from an experiment performed in the 90s (Winters. et al.), does not support this.
This discrepancy gives rise to significant uncertainty in the penetration depth of neutrons through liquid argon, an important parameter for next generation neutrino and dark matter experiments.
In this talk, the first results from the ARTIE experiment will be presented.
The ARTIE measurement of the total cross section as a function of energy confirms the existence of the anti-resonance near 57 keV, but not as deep as the theory prediction.Speaker: Luca Pagani (UC Davis) -
19:15
First results from the HENSA/ANAIS collaboration at the Canfranc Underground Laboratory 15m
Neutrons are one of the main sources of experimental background in underground laboratories. A good knowledge of their spectral distribution is required in order to assess the effect on low counting rate experiments in astrophysics, dark matter and neutrino research. The High Efficiency Neutron-Spectrometry Array (HENSA) has been developed in order to achieve the characterization of the neutron background at the Canfranc Underground Laboratory (LSC).
HENSA is a detection system based on the Bonner Spheres principle [THO02]. In order to be sensitive at different energy ranges (from thermal energies to 10 GeV), it is composed by several independent long 3He-filled proportional counters embedded in High Density PolyEthylene (HDPE) moderators with different sizes. The neutron flux spectrum is obtained from the experimental counting rates by means of iterative reconstruction algorithms. Key to the reliability of the reconstruction process is the use of an initial guess spectrum close to the true spectrum. Early versions of HENSA have already been used for characterization of the neutron background at LSC, before the start of the scientific experiments [JOR13], and in the shallow underground facility Felsenkeller in Dresden [GRI20].
The HENSA/ANAIS collaboration aims for a precise determination of the neutron background, including its possible seasonal fluctuation, affecting ANAIS-112, an experiment looking for dark matter annual modulation with NaI(Tl) scintillators [AMA21]. For the initial tests some modules of the HENSA setup were installed in Hall B at LSC, in a position close to ANAIS-112 setup. The measurements started in March 2021 and a long term characterization of the neutron background in this position is foreseen until December 2022.
In this work, FLUKA Monte Carlo calculations of the neutron background spectrum at the LSC facility will be reported. The simulations are based on previous measurements of the rock composition and intrinsic radioactivity [AMA06]. These calculations provides a guess input for reconstruction of the spectral distribution in HENSA measurements. In addition, the first results of HENSA/ANAIS experimental measurements in Hall B will be presented and discussed.
[AMA06] J. Amaré et al. Journal of Physics: Conference Series 39 (2006) 35.
[AMA21] J. Amaré et al., Physical Review D 103, (2021) 102005.
[GRI20] M. Grieger et al., Physical Review D 101 (2020) 123027.
[JOR13] D. Jordán et al., Astroparticle Physics 42 (2013) 1
[THO02] D.J. Thomas and A.V. Alevra, NIMA 476 (2002) 12–20.`
Speaker: Nil Mont-Geli (Institute of Energy Technologies (INTE), Technical University of Catalonia (UPC)) -
19:15
First search for new forces at the micron scale using optically levitated microspheres 15m
We report on a search for non-Newtonian forces that couple to mass, with a characteristic scale of ${\sim}10~\mu$m, using an optically levitated microsphere as a precision force sensor. A silica microsphere trapped in an upward-propagating, single-beam, optical tweezer is utilized to probe for interactions sourced from a nanofabricated attractor mass with a density modulation brought into close proximity to the microsphere and driven along the axis of periodic density in order to excite an oscillating response. We obtain force sensitivity of ${<}10^{-16}~\rm{N}/\sqrt{\rm{Hz}}$. Separately searching for attractive and repulsive forces results in the constraint on a new Yukawa interaction of $|\alpha| > 10^8$ for $\lambda > 10~\mu$m. This is the first test of the inverse-square law using an optically levitated test mass of dimensions comparable to $\lambda$, a complementary method subject to a different set of system effects compared to more established techniques.
Speaker: Alexander Fieguth (Stanford University) -
19:15
Identification of the cosmogenic $^{11}$C background in the solar neutrino experiment Borexino 15m
Borexino is a liquid scintillator detector situated underground in the Laboratori Nazionali del Gran Sasso in Italy. Its physics program evolves around the study of solar and geo-neutrinos. By now, Borexino has measured neutrinos from the fusion processes in the pp chain and CNO cycle. Especially for the detection of pep and CNO neutrinos, an important background is formed by the cosmogenic radio-isotope $^{11}$C that is produced by muon spallation of $^{12}$C nuclei in the scintillator.
Given the comparatively long life time (30 mins) and high rate (30 cpd and 100 ton), dedicated veto strategies had to be developed to permit the detection of pep and CNO neutrinos. The present contribution presents two veto methods. One is the well-established Three Fold Coincidence (TFC) technique that relies on time and space correlation of muons, spallation neutrons, and radioactive $^{11}$C decays; it has been used in different implementations in all former Borexino analyses. In addition, a newly devised algorithm searching for time-correlated bursts of $^{11}$C events will be presented, highlighting as well the potential gain from a combined application with the TFC technique.
Although both methods have been primarily developed for $^{11}$C tagging in Borexino, they are not limited to this specific experiment or spallation isotope, offering a broad range of potential applications in low-background neutrino experiments.
Speaker: Alessio Porcelli (Universiteit Gent) -
19:15
Implementation of IceTop data in the IceCube Realtime Alert System 15m
The IceCube Neutrino Observatory is a cubic-kilometer detector at the geographic South Pole searching for astrophysical neutrinos. A realtime analysis framework is implemented for multi-messenger time-domain astronomy. When the data acquisition system identifies candidate neutrinos of astrophysical origin, an alert is sent to the multi-messenger community for rapid follow-up observations. The main background for astrophysical neutrinos is leptons produced in cosmic ray air showers: neutrinos from the northern hemisphere and muons from the southern hemisphere. These atmospheric backgrounds are reduced using a data-driven selection based on the observed event energy and arrival direction. An array of ice-Cherenkov tanks on the surface, IceTop, detects showers of secondary particles created in cosmic ray air showers. We will show that data from IceTop can be used to further reduce the background due to atmospheric muons, and we will describe how it has been implemented within the IceCube alert system.
Speaker: Najia Moureen Binte Amin (University of Delaware) -
19:15
Inflationary Dynamics of Tsallis Holographic Scalar Field Models in Chern-Simons Modified Gravity 15m
The study aims to reconstruct the scalar field model of Dark Energy (DE) namely tachyon, k-essence and dilation scalar field models of DE through holographic dark fluid under Chern-Simon's Modified Gravity. $\Lambda$CDM fixed point is attained in case of tachyon scalar field model under this cosmological settings $[1-8]$. Some constraints have been derived on the interaction term as Tsallis Holographic DE parameter in the interacting scenario by considering k-essence scalar field model. Equation of State (EoS) parameter for all the cases have been deduced and found to be consistent with the observational data from Planck+WP+BAO for current universe i.e., at $z=0$. Exception is that, the behaviour of reconstructed scalar field model is phantom $[9-13]$. Evolutionary behaviour of reconstructed scalar field and potential for various cases have been plotted and studied.
References:
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[2] S. Perlmutter et al., Astrophys. J., 517, 565 (1999).
[3] P. Astier et al., Astron. Astrophys., 447, 31 (2006).
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[5] K. Abazajian et al. (SDSS Collaboration), Astron. J., 128, 502 (2004).
[6] K. Abazajian et al., (SDSS Collaboration), Astron. J., 129, 1755 (2005).
[7] D. N. Spergel et al., (WMAP Collaboration), Astrophys. J. Suppl., 148, 175 (2003).
[8] D. N. Spergel et al., (WMAP Collaboration), Astrophys. J. Suppl., 170, 377 (2007).
[9] M. Tavayef, A.Sheykhi, K. Bamba, H. Moradpour, Phys. Lett. B, 781, 195 (2018).
[10] S. Nojiri, S. D. Odintsov, H. Stefancic, Phys. Rev. D, 74, 086009 (2006).
[11] S. Nojiri, S. D. Odintsov, J. Phys. A, 40, 6725 (2007).
[12] G. Cognola, E. Elizalde, S. Nojiri, S. D. Odintsov, S. Zerbini, Phys. Rev. D, 75, 086002
(2007).
[13] S. Nojiri, S. D. Odintsov, J. Phys. Conf. Ser., 66, 012005 (2007).Speaker: Gargee Chakraborty (Amity University, Kolkata) -
19:15
Influence of NaI background and mass on testing the DAMA modulation 15m
We present here the model dependent and independent sensitivity studies for NaI detectors designed to test the DAMA result and compare the predicted limits from SABRE with the present performance of both COSINE and ANAIS. We find that the strongest discovery and exclusion limits are set by a detector with the lowest background (assuming equal run times), and also note that our method correctly computes the present exclusion C.L. previously published by ANAIS and COSINE. In particular, with a target mass of 50 kg and background rate of 0.36 cpd/kg/keV (after veto), SABRE will be able to exclude the DAMA signal with 3$\sigma$ confidence or `discover' it with 5$\sigma$ confidence within 2 years. This strongly motivates the quest for ever lower backgrounds in NaI detectors.
Speaker: Madeleine Zurowski (University of Melbourne) -
19:15
Likelihood Methods in the CRESST-Experiment 15m
Despite overwhelming astrophysical evidence for the existence of Dark Matter and intense efforts towards its detection, no clear signal has been found so far. Nonetheless, monumental advancements have been made in the field which allowed to put significant constraints on the parameter space for possible particle candidates. For this reason, various statistical methods have been employed and developed. For many direct dark matter searches the optimal interval method, an extension of the maximum gap method developed by Yellin, has been the golden standard. Recently however, many experiments have shifted to maximum likelihood based methods for their statistical data analysis.
CRESST is a direct Dark Matter search experiment utilizing scintillating cryogenic bolometers as detectors. This detector principle allows for an extremely low detection threshold as well as particle discrimination. These features allowed CRESST to be one of the leading experiments in low-mass Dark Matter searches for many years.
In this contribution an application of the maximum likelihood formalism to the data of CRESST detectors is presented. Recent improvements in detector performance and better understanding of the detector behavior have made the use of a complete and un-binned likelihood approach both possible and beneficial. This method enables a better understanding of the properties of individual detectors as well as the use of profile likelihood for limit calculations.
Speaker: Daniel Schmiedmayer (TU-Wien & HEPHY Vienna) -
19:15
Measurement of cosmogenic neutron production in SK-Gd 15m
SK-Gd experiment has been started with gadolinium (Gd) added to ultra-pure water in Super-Kamiokande. SK-Gd dramatically improves the sensitivity to supernova relic neutrino searches by tagging neutrons. Cosmic-ray muons flying into Super-Kamiokande induce hadronic showers. Those break oxygen nuclei in water and produce unstable radioactive isotopes and neutrons, which are major background sources for supernova relic neutrino searches.
In addition, the cosmogenic neutrons can be used for the detector calibration source. Since cosmic-ray muons fly into Super-Kamiokande continuously with the rate of 2 events/s, the cosmogenic neutrons can be used to check the stability and uniformity of the Gd concentration in the detector.
In this presentation, I will report the current status of cosmogenic neutron measurement in SK-Gd.Speaker: Masataka Shinoki (Tokyo University of Science) -
19:15
Metallic Magnetic Calorimeters for the BabyIAXO experiment 15m
The next generation helioscopes BabyIAXO and IAXO will search for evidence of axions and axion-like particles (ALPs) produced in the center of the Sun. In the helioscope a strong magnetic field would convert ALPs via the generic ALP-photon coupling into photons. A very promising candidate for the focal plane X-ray detectors are low temperature metallic magnetic calorimeters (MMCs). Combining good energy resolution and high quantum efficiency, MMC-based detectors would allow to investigate the solar axion spectrum and derive information on axion models beyond discovery. Furthermore, by analyzing the resulting X-ray spectrum, details about the interior of the Sun could be deduced.
In this contribution, we present the 8x8 pixel detector array maXsIAXO which was specifically optimized for the needs of BabyIAXO. This detector features an absorber area of 1 cm$^2$ with a filling factor of 94.4 $\%$ to match the focal spot size of the X-ray optics. The X-ray absorbers have a thickness of 10 µm and are made of gold to ensure a high stopping power over the complete energy range of interest up to 8 keV as well as around 14 keV where a strong line is expected. The expected energy resolution is about 11 eV (FWHM). At the light of a background characterization of similar MMC arrays, we conclude discussing the advantages of using this X-ray detector system for BabyIAXO and IAXO.Speaker: Andreas Abeln (Kirchhoff-Institute for Physics, Heidelberg University) -
19:15
Migdal event rates for D-D and D-T neutron generators 15m
The ‘Migdal effect’ is an atomic physics effect that leads to the emission of a bound-state electron from atomic or molecular systems when the atomic nucleus is suddenly perturbed. This effect has been used by several experimental collaborations to extend the sensitivity of dark matter direct experiments to sub-GeV mass dark matter candidates. The MIGDAL (Migdal In Galactic Dark mAtter expLoration) collaboration has been formed to detect the tell-tale signature of an electron that has been ejected from an atom or molecule upon the scattering of fast neutrons, providing a unique and unambiguous measurement of the Migdal effect. The experiment will run with intense D-D and D-T neutron generators at the Rutherford Appleton Laboratory (RAL) in the UK.
In this talk, I will present the atomic-physics theory underlying the Migdal effect and discuss the differences and similarities of the effect between dark matter direct detection experiments and at the D-D and D-T neutron energies employed at RAL. I will then present estimates for the number of events that can be observed at the experimental set-up at RAL for several different gas species.Speaker: Christopher McCabe (King's College London) -
19:15
Model independent approach to photodisintegration of $^7Li$ at the range of energies of interest to BBN 15m
One of the elements that was synthesized primordially in the standard Big Bang Nucleosynthesis is Lithium. Lithium, being fragile gets easily destroyed at relatively low temperatures in the mixing process between stellar surface and hot internal layers. So that, at the end of the stellar lifetime the lithium content is believed to be depleted. Series of experimental measurements on lithium isotopes were carried out at High Intensity Gamma Ray Source (HIGS) at Duke Free Electron Laser Laboratory. More recently experiments [1]-[2] were performed , to measure the differential cross section of the photo-neutron reaction channel in photodisintegration of $^7Li$, where the progeny nuclei is in the ground state as well as in excited states .
The purpose of present contribution is to study the reaction channel $ ^7Li+ \gamma \to$ $^6Li+n $ using linearly polarized photons . The model independent irreducible tensor formalism [3]-[5] will be used to study the differential cross section of the reaction. We study the angular dependence of differential cross section by expressing differential cross section in terms of legendre polynomials. In view of the several theoretical and ongoing experimental studies, a detailed theoretical study of the spin structure of the amplitudes in $ ^7Li+ \gamma \to ^6Li+n $ and their expansion in terms of 'electric' and `magnetic' amplitudes is needed to analyze the measurements of spin observables as well as differential cross section, which leads to a better understanding of the problem at astrophysical energies.References:
[1]W. A. Wurtz, R. E. Pywell , B. E Norum, S. Kucuker , B. D. Sawatzky, , H. R. Weller, M. W. Ahmed, S. Stave, “Measurement of the absolute and differential cross sections for 7Li(γ, n0),” Phys.Rev.C, , 84, 044601 (2011).
[2]W. A. Wurtz, R. E. Pywell, B. E. Norum, S. Kucuker, B. D. Sawatzky, H. R. Weller, S. Stave, M.W.Ahmed, “Photodisintegration of 7Li with progeny nuclei in excited states,” Phys.Rev.C, 92, 044603 (2015).
[3]G. Ramachandran, S. P. Shilpashree, “Deutron disintegration of polarised photons at astrophysical energies,” Phys.Rev.C, 74, 052801(R) (2006).
[4]G. Ramachandran, Yee. Yee. Oo, S. P. Shilpashree, “Photodisintegration of polarides deuteron at astrophysical energies,” J.Phys.G:Nucl.Part.Phys , 32, B17 – B21 (2006).
[5]S. P. Shilpashree, Swarnamala. Sirsi, G. Ramachandran, “Photodisintegration of aligned deuteron at astrophysical energies using linearly polarised photons,” Int.Jou.Mod.Phys.E, 22, 1350030 (2013).Speaker: Aswathi V (Christ University ) -
19:15
Neutrino Mixing by modifying the Yukawa coupling structure of constrained sequential dominance 15m
In the constrained sequential dominance (CSD), tri-bimaximal mixing (TBM) pattern in the neutrino sector has been explained, by proposing a certain Yukawa coupling structure for the right-handed neutrinos of the model. However, from the current experimental data it is known that the values of neutrino mixing angles are deviated from the TBM values. In order to explain this neutrino mixing, we first propose a phenomenological model where we consider Yukawa couplings which are modified from that of CSD. Essentially, we add small complex parameters to the Yukawa couplings of CSD. Using these modified Yukawa couplings, we demonstrate that neutrino mixing angles can deviate from their TBM values. We also construct a model, based on a flavor symmetry, in order to justify the modified form of Yukawa couplings of our work.
Speaker: Joy Ganguly (Indian Institute of Technology Hyderabad) -
19:15
New BSM signatures in large scale detectors from terrestrial upscattering 15m
In this talk I will discuss how large volume detectors can be used to search for new physics generated via up-scattering within the Earth itself. The production of new particles can be sourced by dark matter, neutrinos, or any other particle capable of penetrating into the Earth's surface. I will focus on neutrino portals and their prospects at experiments such as Super-Kamiokande, Borexino and ICECUBE.
Speakers: Ryan Plestid (University of Kentucky/Fermilab), Andrew Gustafson (Virginia Tech) -
19:15
nEXO light detection system 15m
nEXO is a future 5-tonne scale Liquid Xenon experiment looking for neutrino-less double beta decay of isotope Xe-136. To attain the projected half-life sensitivity of ~10^28 years, at least 1% of energy resolution is required at the Q-value (Qββ = 2.458 MeV) of the decay.
nEXO has planned to employ Silicon Photomultipliers (SiPMs) along the barrel of the cylindrical Time Projection Chamber with the electrons drifting towards anodes located on the cylinder top endcap. The energy resolution is driven in large part by the light detection capability, with a minimum of 3% of scintillation photons having to be detected.
Newly developed vacuum ultra-violet (VUV) SiPMs will be used for detecting scintillation photons with wavelength in the ultraviolet regime (165-195 nm). For achieving the target energy resolution, the SiPMs must have high photon detection efficiency (>15%) accompanied by low correlated avalanche noise and low dark noise rates. The primary goal of this research project is to characterize the VUV-SiPMs and measure their various features like gain, crosstalk, afterpulsing, dark noise rate, reflectivity and photon detection efficiency. Along with all these measurements, a well-established monitoring tool will be required to test the large number of SiPMs before installation in the detector. IV (current-voltage) curve characterisation is being explored as a rapid testing tool for the performances of SiPM. In this talk, the results from characterisation of nEXO SiPMs and IV curve based SiPM monitoring method will be presented.Speaker: Bindiya Chana (Carleton University) -
19:15
Operation update and Calibration plan for the Scintillating Bubble Chamber (SBC) Collaboration's 10-kg LAr detector at Fermilab 15m
The Scintillating Bubble Chamber (SBC) Collaboration is developing a novel detection technique aimed at detecting low-mass (0.7-7 GeV/$c^2$) WIMP interactions and coherent elastic neutrino-nucleus scattering (CE$\nu$NS) of reactor neutrinos. Using a target volume composed of superheated argon with xenon doping, the nucleation signal from electron recoils (the limiting factor for low-threshold studies in bubble chambers) is suppressed, allowing for the exploration of new parameter space. Particle interactions with the target fluid can lead to the production of heat (bubbles) and scintillation light. By combining these observables, the SBC Collaboration is aiming to reach a threshold of 100 eV for nuclear recoil detection with discrimination, to be demonstrated for the first time in a 10-kg device at Fermilab.
In this talk, I will discuss current activities at Fermilab towards the commissioning and operation of this device. I will also discuss our calibration run plan, which aims to measure the response of this chamber to both electron- and nuclear-recoils at the target 100-eV threshold.
Speaker: Sumanta Pal (Univ. of Alberta, McDonald Institute) -
19:15
Performance evaluation of 3-inch PMT for Hyper-Kamiokande 15m
Hyper-Kamiokande is the next generation water Cherenkov detector for the study of neutrino oscillations including the search for leptonic CP violation using high intensity neutrino beam produced in J-PARC. In order to reduce the systematic uncertainty of the CP violation measurement, a 1kton scale Intermediate water Cherenkov detector (IWCD) is planned to be constructed around 1km downstream the J-PARC neutrino beamline. The multi-PMT modules, which consist of 19 3-inch PMTs will be installed in the IWCD to improve the detector performance with their higher granularity.
In this poster, we will present the measurements of the performance for 3-inch PMT such as time resolution, dark noise rate and relative photon detection efficiency.Speaker: Tatsushi Kinoshita -
19:15
Probing Lorentz Invariance Violation with Atmospheric Neutrinos at INO-ICAL 15m
Unified theories such as string theory suggests spontaneous Lorentz Invariance Violation(LIV) by introducing a new spacetime structure at the Planck Scale ($m_p \sim 10^{19}$ GeV). This effect can be observed at low energies with strength of $\sim 1/m_p$ using perturbative approach. In the Minimal Standard Model Extension (SME) framework, the neutrino mass-induced flavor oscillation gets modified in the presences of LIV. The Iron Calorimeter (ICAL) detector at the proposed India-based Neutrino Observatory (INO) offers an unique window to probe these LIV parameters by observing atmospheric neutrinos and anti neutrinos separately over a wide range of baselines in the multi-GeV energy range. In this paper, for the first time, we study in detail how the CPT-violating LIV parameters $(a_{e\mu}, a_{e\tau}, a_{\mu\tau})$ can alter muon survival probabilities and expected $\mu^-$ and $\mu^+$ event rates at ICAL. Using 500 kt$\cdot$yr exposure of ICAL, we place stringent bounds on these CPT-violating LIV parameters at 95% C.L which are slightly better than the present Super-Kamiokande limits. We discuss the effect of the marginalization over the oscillation parameters and the advantage of having the hadron energy information and charge identification capability at ICAL in constraining these LIV parameters. We also study the impact of these LIV parameters on mass ordering determination and precision measurement of atmospheric oscillation parameters.
Speaker: Sadashiv Sahoo (Institute of Physics Bhubaneswar; Homi Bhabha National Institute Mumbai) -
19:15
Probing the magnitude of asymmetries in the lateral density distribution of electrons in EAS 15m
The lateral density distributions (LDD) of inclined cosmic ray air shower are asymmetric and the corresponding iso-density contours are of increasing eccentric ellipses with zenith angles of different showers. The polar asymmetry of the iso-density contours introduces a significant shift of the EAS core, which is quantitatively expressed as a gap length (GL) parameter between the EAS core and the center of the modified density pattern consisting of several equi-density ellipses. The LDD of EAS particles is usually approximated by a particular type of lateral density function (LDF) which is generally assumed to be polar symmetric about the EAS axis, and cannot describe the asymmetric LDDs accurately. A polar angle-dependent modified lateral density function of EASs has been derived analytically by considering the effect of attenuation of EAS particles in the atmosphere. From the simulation studies, it has been found that the GL manifests sensitivity to the cosmic ray mass composition. The cosmic ray mass sensitivity of the lateral shower age is also re-examined by applying the modified LDF to the simulated data.
Speaker: Animesh Basak (North Bengal University) -
19:15
Recent advancements of the experiment to search for 2K capture in $^{124}$Xe using a large proportional counter 15m
Here we report the current sensitivity of the large proportional counter to a $^{124}$Xe 2$\nu$ECEC filled with xenon gas up to 5 atm. One of the main procedures for detecting ECEC decays of $^{124}$Xe in an experiment using a gas target is identifying three charge ionization clusters released during the absorption of two X-ray quanta and Auger electrons from a daughter atom. The developed new algorithm for digital processing of signals taken from the detector made it possible to consider the loss of electrons due to diffuseness and recombination in the track and correct the total energy release for the response of a separate absorbed particle. Thus, by increasing the efficiency of selecting useful events, we expect an increase in the sensitivity to the half-life 2$\nu$2K-mode for a 6-year run to $2×10^{22}$ y (at 90% C.L.) in the current experiment.
Speaker: Vladimir Kazalov (INR RAS) -
19:15
Simulation-based shielding design of the COSINUS experiment 15m
The COSINUS experiment aims for probing the nature of the long-standing annual modulation signal observed by the DAMA/LIBRA collaboration. After successful years of detector prototyping, the construction of a dedicated experimental facility will start this year in Hall B of the LNGS underground laboratory. At the heart of the setup, NaI crystals – the same material as used in DAMA/LIBRA – will be operated as scintillating cryogenic calorimeters.
To reach the necessary sensitivity to potential signals, background mitigation is of utmost importance. Besides using radiopure crystals and going underground, this can be achieved by surrounding the detectors with dedicated passive (and active) shielding layers. To optimize these layers and hence minimize background contributions from environmental radioactivity as well as intrinsic contamination of materials used for cryostat, shielding and infrastructure, we performed detailed Monte Carlo simulations.
In this contribution, we will present the results of our simulation studies together with the final design of the COSINUS experimental setup.
Speaker: Alexander Fuss (TU Wien & HEPHY) -
19:15
Spin and spin-flavor oscillations due to neutrino charge radii interaction with an external environment 15m
It is believed that the running (for instance, COHERENT) and forthcoming terrestrial neutrino experiments will be sensitive to the neutrino charge radius [1] that is one of the neutrino fundamental electromagnetic characteristics [2] predicted [3] to be non-zero even in the Standard Model. In this work we continue our studies [4] on neutrino oscillations accounting for diagonal and non-diagonal neutrino charge radii. We consider spin and spin-flavor neutrino oscillations in an extreme astrophysical environment and on the basis of exact expressions for the corresponding neutrino oscillation probabilities we study conditions for possible neutrino resonances engendered by the neutrino charge radii. We apply the obtained results to an extreme astrophysical environment.
This research has been supported by the Interdisciplinary Scientific and Educational School of Moscow University “Fundamental and Applied Space Research” and also by the Russian Foundation for Basic Research under Grant No. 20-52-53022-GFEN-a. The work of KS is also supported by the RFBR under grant No. 20-32-90107 and by the “BASIS” Foundation No. 20-2-2-3-1.
[1] M.Cadeddu, F.Dordei, C.Giunti, K.Kouzakov, E.Picciau, A.Studenikin, Phys.Rev.D 100 (2019) 073014.
[2] C.Giunti, A.Studenikin, Rev.Mod.Phys. 87 (2015) 531.
[3] J.Bernabeu, L.G.Cabral-Rosetti, J.Papavassiliou, J.Vidal, Phys.Rev.D 62 (2000) 113012.
[4] K.Kouzakov, F.Lazarev, V.Shakhov, K.Stankevich, A.Studenikin, PoS ICHEP2020 (2021) 217.Speaker: Konstantin Stankevich (Moscow State University) -
19:15
Study of He-CF4-isobutane mixtures for directional dark matter searches with the CYGNO Time Projection Chamber 15m
CYGNO is developing a gaseous Time Projection Chamber (TPC), which will be hosted at Laboratori Nazionali del Gran Sasso, Italy, and will rely on a triple Gas Electron Multiplier (GEM) stack for charge multiplication and electroluminescence (EL) production. The EL will be collected with a high resolution scientific camera for particle identification and 2D track reconstruction, with the aim of discriminating nuclear recoils and their direction.
This work aims at determining how the addition of small percentages of isobutane to the He-CF4 (60/40) select CYGNO TPC gas mixture influences the EL yield, charge gain and energy resolution. A Large Area Avalanche Photodiode (LAAPD) was used to readout the EL produced in the avalanches of a single GEM. Isobutane fractions up to 5% were added to the CYGNO He/CF4 (60/40) base mixture.
Our results show that the inclusion of isobutane does not severely compromise the amount of EL photons detected, while maintaining the energy resolution and increasing the charge gain of the CYGNO He-CF4 (60/40) base mixture.Speaker: Fernando Amaro (LIBPys - Coimbra University) -
19:15
Supernova neutrino burst search at KamLAND 15m
The observation of neutrinos from SN1987A had improved our understanding of
the mechanism of the supernova explosion and neutrino properties. Now, several state-of-the-art neutrino detectors are running. There is a chance to reveal the explosion mechanism and neutrino properties in more details. In this study, we search for neutrino events from supernovae with KamLAND, which is a 1kt liquid scintillator detector, via inverse-beta decay reaction. KamLAND can measure low energy events ($E_{\nu}>1.8$MeV) with low background conditions from delayed-coincidence scheme and have long-term stable data from 2002, including an unexplored dataset by other neutrino detectors (Dec. 2013 ~ Jul. 2020). Selection criteria for supernova events are two or more inverse beta decays within 10 s. We present the search results and upper limits on supernova rate in our galaxy.Speaker: Minori Eizuka (RCNS, Tohoku Univ.) -
19:15
The cosmic muon-induced background for the LEGEND-1000 Alternative Site at LNGS 15m
The in-situ production of long-lived isotopes by cosmic muon interactions may generate a non-negligible background for the search for rare events in the deep subsurface, defining a minimum depth requirement. Monte Carlo studies for a GERDA-like experiment at LNGS-depth identified the delayed decay of $^{77(\mathrm{m})}$Ge as the dominant in-situ cosmogenic background in the search for the neutrinoless double-beta decay of $^{76}$Ge [1,2], with a projected background index (BI) of $2.7\times 10^{-6}$ cts/(keV$\cdot$kg$\cdot$yr) after delayed coincidence rejection at Q$_{\beta\beta}=2039~\mathrm{MeV}$ [2]. The future tone-scale LEGEND-1000 experiment requires a total BI from all individual contributions of $\leq10^{-5}$ cts/(keV$\cdot$kg$\cdot$yr) [3,4]. Dedicated Monte Carlo simulation studies of the $^{77(\mathrm{m})}$Ge background for LEGEND-1000, including different mitigation strategies, were performed at the alternative LNGS site, as opposed to the SNOLAB baseline site. We will present the effects of passive and active measures to further reduce this background contribution to meet the overall background requirements.
[1] L. Pandola et al., Nucl. Instr. Methods A 570 (2007) 149
[2] C. Wiesinger et al., Eur. Phys. J. C (2018) 78:597
[3] AIP Conference Proceedings, Volume 1894, Issue 1, id.020027
[4] LEGEND-1000 pCDR. To be available at https://legend-exp.org/science/publicationsSpeaker: Moritz Neuberger (TUM (Techincal University Munich)) -
19:15
Transition neutrino magnetic moments in CE$\nu$NS 15m
Coherent Elastic Neutrino Nucleus Scattering (CE$\nu$NS) is a novel technique to look for new physics beyond the Standard Model. We study the prospects of probing a transition magnetic moment in CE$\nu$NS experiments, and the potential to shed light on the Dirac vs Majorana nature of neutrinos. We show the NUCLEUS experiment as an example, and demonstrate that properties of a potential sterile neutrino can be deduced through a consideration of the final state distribution.
Speaker: Kåre Fridell (Technical University of Munich) -
19:15
Tunka-Grande scintillation array: resent results 15m
The number of the objectives of the TAIGA Astrophysical complex includes the study of the flux of charged cosmic rays and diffuse gamma rays with energies above 100 TeV. This complex is located in the Tunka Valley, about 50 km from Lake Baikal at the site of the Tunka-133 Cherenkov facility. TAIGA includes the TAIGA-HiSCORE wide-angle Cherenkov array, the network of Imaging Atmospheric Cherenkov Telescopes (TAIGA-IACT), the Tunka-Grande and TAIGA-Muon scintillation arrays.
The results of an analysis of the joint events of the Tunka-Grande scintillation array and TAIGA-HiSCORE and Tunka -133 Cherenkov facilities are presented. Joint events comparison results verify scintillation experiment sufficient accuracy for the joint study of mass composition of cosmic rays and gamma-hadron separation.Speaker: Anna Ivanova (Irkutsk State University) -
19:15
What is a breakdown of continuous component hidden under 4.4-MeV gamma-ray peak from the AmBe source? 15m
Americium-Beryllium (AmBe) is a typical source to be use for a calibration of neutron detection efficiency in underground astroparticle experiments. It has been considered to emit a neutron and 4.4 MeV gamma ray simultaneously, which allows us to select events with a neutron by tagging the 4.4 MeV gamma-ray signal. This time, we focus on the higher energy component around 5-10 MeV in a deposited energy distribution,under the measurement with inorganic scintillators. Any component hidden under the 4.4 MeV peak could be counted with no neutron emission in the tagging events. We aim to understand the breakdown of the continuous component from the AmBe source to contribute reduction of a systematic uncertainty related to the neutron detection efficiency for the astroparticle physics. We will present a result of measurements for neutrons and gamma rays using NaI(Tl) and liquid scintillation detectors.
Speaker: Kohei Wada (Yokohama National University)
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Hot topic Dark Matter: 3
Chairs: Susana Cebrián (1), Riccardo Catena (2), Roberto Santorelli (3)
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13:30
Sensitivity of CTA to gamma-ray emission from the Perseus galaxy cluster 15m
We estimate the sensitivity of the Cherenkov Telescope Array (CTA) to detect diffuse gamma-ray emission from the Perseus galaxy cluster, both from interactions of cosmic rays (CR) with the intra-cluster medium, or as a product of annihilation or decay of dark matter (DM) particles in case they are weakly interactive massive particles (WIMPs). The observation of Perseus constitutes one of the Key Science Projects proposed by the CTA Consortium for the first years of operation of the CTA Observatory. In this talk, we will focus on the DM-induced component of the flux. Our DM modeling includes the substructures we expect in the main halo of Perseus, as predicted within the standard cosmological model hierarchical structure formation scenario, which will boost the annihilation signal significantly. We compute the expected CTA sensitivity using a likelihood maximization analysis including the most recent CTA instrument response functions. We also model the expected CR-induced gamma-ray flux in the cluster, and both DM- and CR-related uncertainties via nuisance parameters. We will show the sensitivity of CTA to discover, at best, diffuse gamma-rays in galaxy clusters for the first time. Even in absence of signal, we show that CTA will allow us to provide stringent and competitive constraints on TeV DM, that will rely on state-of-the-art modeling of the cluster's DM distribution. Finally, we will discuss the optimal strategy for CTA observations of Perseus.
Speaker: Judit Pérez-Romero (IFT UAM-CSIC) -
13:45
Combined Dark Matter searches from dwarf spheroidal galaxies observations by Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS 15m
Dwarf spheroidal galaxies (dSphs) are ideal targets for Dark Matter (DM) indirect searches due to their high DM content and their negligible expected astrophysical background. In this presentation, we report on the combined analysis of the observations of 20 dSphs by Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS collaborations in the search for DM, focusing on the Weakly Interacting Massive Particles (WIMPs) scenario. The combined analysis allows us to maximize the sensitivity by combining individual data sets from all five experiments for which the energy ranges of the search overlap. New constraints, spanning a range of DM masses from 5 GeV to 100 TeV, on the velocity-weighted cross section for DM self annihilation will be presented.
Speaker: Daniel Kerszberg (IFAE-BIST) -
14:00
Results of axion searches at 34 μeV with RADES haloscope and prospects for searches in BabyIaxo 15m
The Relic Axion Detector Exploratory Setup (RADES) detector employs rectangular cavities joined by irises to search for axion dark matter between 8 and 9 GHz present in the galactic halo using the haloscope technique. The first results for an axion search in the mass range 34.6738 μeV < $m_a$< 34.6771 μeV using a detector made of 5 sub cavities joined by inductive irises installed at CAST will be presented. The result showcases the potential of using dipole magnets for haloscope searches and opens a possibility to use larger magnet bore size such as foreseenin future axion telescopes as babyIAXO. The physics potential of using taller cavities resonating at 8 GHz and longercavities resonating at 250 MHz is being explored. Also, the designs and prospects (studied by the RADES working group) for such cavities will be shown.
Speaker: Sergio Arguedas Cuendis
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Hot topic Gravitational Waves
Chair: Toni Font
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Search for unmodeled long duration gravitational waves for Advanced LIGO and Advanced Virgo's third observing run 15m
Many astrophysical phenomena are foreseen to emit GW transient signal with long duration (since few up to few hundreds seconds), such as fallback accretion, accretion disk instabilities, nonaxisymmetric deformations in magnetars. The theoretical predictions for those astrophysical processes cover a wide range of signal morphologies and in most cases are poorly known. In such cases, we need unmodeled search techniques.
We report on results of unmodeled long-duration transient searches in the third observing run of Advanced LIGO and Advanced Virgo. The search is performed using minimal assumptions and covers the range of 2s-500s duration in the frequency band of 24Hz-2048Hz. We use three different algorithms to improve detection capability and coverage of search parameter space thanks to different assumptions and data handling techniques.Speaker: Claudia Lazzaro (Università degli Studi di Padova) -
13:45
Gravitational-wave lensing with ground-based gravitational-wave detectors 15m
Gravitational waves, like light, could be gravitationally lensed by intervening matter. Recent studies suggest that we might see gravitational-wave lensing within the coming years as the current ground-based detectors are upgraded. However, the methods to detect and employ gravitational-wave lensing are entirely different from light lensing. Indeed, we detect waves instead of particles, and the source population is one of merging black holes. For these reasons, the field might also pave the way to new applications. Here I will discuss some of our recent work in the field.
Speaker: Otto Hannuksela -
14:00
State-of-the art parameter estimation of gravitational wave events with the new phenomenological waveform models in frequency and time domain 15m
In this talk we present in-depth state-of-the-art parameter estimation studies of several gravitational wave events with open LIGO-Virgo data.
We use the fourth generation of phenomenological waveform models, the frequency domain IMRPhenomX and the time domain IMRPhenomT families which include higher harmonics and precession, and constitute the computationally most efficient inspiral-merger-ringdown frequency and time domain waveform models for binary black holes with are currently available in the LALSuite software framework. We systematically compare the Bilby and LALInference frameworks for parameter estimation, and perform highly parallel simulations in a traditional supercomputing environment. We discuss our automatisation of Bayesian inference runs, and the use of a machine learning model in order to predict the duration of a PE run or its number of likelihood evaluations. Due to the computational efficiency of the waveform models we can perform systematic tests of different priors, sampler settings, waveform models and inference codes. We discuss the computational cost, and the wall-clock time required to get fast parameter estimation results, and aspects of the systematic uncertainties in the waveform models. Regarding results, special emphasis is put on the intermediate mass black hole GW190521 event, which is astrophysically particularly interesting, but also particularly challenging due to the shortness of the signal.Speaker: Maite Mateu-Lucena (University of the Balearic Islands)
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Hot topic HE astrophys. & CRs/Multi-messenger astronomy: 2
Chairs: Ioana Maris (1), Miquel Ardid (2)
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LST-1, the Large-Sized Telescope prototype of CTA: status and first observations. 15m
CTA (Cherenkov Telescope Array) is the next generation ground-based
observatory for gamma-ray astronomy at very-high energies. Once
completed, CTA will outperform present-day facilities by an order of
magnitude in sensitivity, and significantly enlarge the accessible energy
range and survey capabilities. Deployed in the CTA north site, on the
island of La Palma (Spain), LST-1 is the prototype for the CTA Large-Sized
Telescopes, which will cover the lower end of the energy range of the array,
down to 20 GeV. LST-1 started astronomical observations in late 2019, and
is currently completing its commissioning phase. We will present the
status of the instrument and an overview of the first physics results.Speaker: Abelardo Moralejo Olaizola (Institut de Física d'Altes Energies (IFAE-BIST), Barcelona) -
13:45
A novel multimessenger study of Starburst galaxies: implications for neutrino astronomy 15m
Starburst galaxies (SBGs) and more in general starforming galaxies represent a class of galaxies with a high star formation rate (up to 100 Mo/year). Despite their low luminosity, they can be considered as guaranteed “factories” of high energy neutrinos, being “reservoirs” of accelerated cosmic rays and hosting a high density target gas in the central region. The estimation of their point-like and diffuse contributions to the neutrino astrophysical flux measured by IceCube can be crucial to describe the diffuse neutrino spectral features as well as the peculiar point-like excess like NGC1068. To this aim we use the most update gamma-ray catalog of this class of objects to perform a multimessenger study and describe their gamma-ray emission through a calorimetric scenario.
For the diffuse analysis we perform a blending of the measured spectral indexes and obtain a multi-component description of extragalactic background light (EGB), high energy starting events (HESE) and high-energy cascade IceCube data. Remarkably, we find that, differently from recent prototype scenarios, the spectral index blending allows starburst galaxies to account for up to 40% of the HESE events at 95.4% CL and favors a maximal energy of the accelerated cosmic rays at teens of PeV.
For the point like analysis we apply the calorimetric approach to the known SBGs within 100 Mpc, considering, were possible, a source-by-source description of the star formation rate. These results are then compared with what IceCube and ANTARES have seen at TeV energies as well as with what can be expected from the incoming KM3NeT.
Speaker: Antonio Ambrosone (University of Naples Federico II and Istituto Nazionale di Fisica Nucleare sezione Napoli) -
14:00
New Properties of Primary Cosmic Rays observed by the Alpha Magnetic Spectrometer on the International Space Station 15m
We report the observation of new properties of primary cosmic-ray neon (Ne), magnesium (Mg), silicon (Si) and iron (Fe) nuclei measured in the rigidity range from 2 GV to 3 TV by the Alpha Magnetic Spectrometer on the International Space Station. The properties of the light primary cosmic-ray helium (He), carbon (C) and oxygen (O) nuclei will be also discussed, showing that Ne, Mg, Si and He, C, O form two different classes of primary cosmic rays, and that unexpectedly Fe belongs to the class of light primary cosmic rays He, C, and O.
Speaker: Mercedes Paniccia (University of Geneva (CH))
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Dark matter search in accelerators and beyond 30m
Chair: Carlos Muñoz
Speaker: Gaia Lanfranchi (LNF) -
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Indirect detection of dark matter 30m
Chair: Carlos Muñoz
Speaker: Francesca Calore (LAPTH Annecy) -
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Break 30m
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Future GW detectors in space and ground 30m
Chair: Jan Harms
Speaker: Harald Lück (MPI for Gravitational Physics) -
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Gravitational waves: technology and current detectors 30m
Chair: Jan Harms
Speaker: Lisa Barsotti (MIT Cambridge) -
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Discussion Panel Dark Matter 8
Chair: Riccardo Catena
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WimPyDD: an object-oriented Python code for WIMP-nucleus scattering direct detection in virtually any scenario 15m
We introduce WimPyDD, a modular, object–oriented and customisable Python code that accurately predicts the expected WIMP-nucleus scattering rates in WIMP direct–detection experiments including the response of the detector. WimPyDD utilises the framework of Galilean–invariant non–relativistic effective theory, allowing to handle an arbitrary number of effective operators, and can perform the calculation of the excepted rate in virtually any scenario, including inelastic scattering, WIMPs with an arbitrary spin, and a generic velocity distribution in the Galactic halo. The power and flexibility of WimPyDD will be discussed in some explicit examples as well as in several published results.
Speaker: Gaurav Tomar (Technical University of Munich) -
17:25
DM-like anomaly in neutron multiplicity spectra 15m
A new experiment collects data, since November 2019, at a depth of 210 m.w.e. in the Callio Lab [1] in the Pyhasalmi mine [2] in Finland. The setup, called NEMESIS (New EMma Experiment Searching for Indirect Signals), incorporates infrastructure from the EMMA experiment [3] with neutron and large-area plastic scintillator detectors of the MAZE system [4]. The experiment's primary aim is to combine muon tracking with position-sensitive neutron detection to measure precision yields, multiplicities, and lateral distributions of high-multiplicity neutron events induced by cosmic muons in various materials. The data are relevant for background evaluation of the deep-underground searches for Dark Matter (DM), neutrino-less double beta decay, etc.
Preliminary analysis revealed anomalies in muon-suppressed neutron multiplicity spectra collected during a 349-day run (live time) with a 565 kg Pb target. The spectra, well described by a power-law fit, show three peaks at high multiplicities. Although still at a low statistical significance, these small excesses match the outcome of an earlier measurement [5]. The nature of the anomalies remains unclear, but, in principle, they may be a signature of self-annihilation of a WIMP with a mass close to 10 GeV/c2 [6]. With that assumption, the expected cross-section would be around 10^-42 cm2 for Spin Dependant and 10^-46 cm2 for Spin Independent interactions. We propose verifying this hypothesis with an upgraded NEMESIS experiment, able to collect an order of magnitude more data than this measurement. Based on the statistical uncertainty, analysis of the event rate indicates that cross-section limits for DM mass range of approximately 3-40 GeV/c2 can be investigated with such a setup.
- Callio, https://callio.info
- W.H. Trzaska et al., (2018), https://arxiv.org/abs/1810.00909
- P. Kuusiniemi et al., AP 102(2018)67 https://www.sciencedirect.com/science/article/abs/pii/S092765051730333X
M. Kasztelan et al., (2006) Proc. the 20th ECRS, Lisbon
https://www.lip.pt/events/2006/ecrs/proc/ecrs06-s0-92.pdf - T. Ward, private communication and AIP Conference Proceedings 842, 1103 (2006); https://doi.org/10.1063/1.2220467
- T.E. Ward et al., APS April Meeting 2019, https://meetings.aps.org/Meeting/APR19/Session/G17.1
Speaker: Wladyslaw Henryk Trzaska (University of Jyvaskyla) -
17:40
The impact of operator interference in dark matter direct detection experiments 15m
The non-relativistic effective theory of WIMP-nucleon interactions depends on 28 coupling strengths. Due to the vast parameter space of the effective theory, most direct detection experiments interpret the results of their searches assuming that only one of the coupling strengths is non-zero. On the other hand, dark matter models generically lead in the non-relativistic limit to several interactions which interfere with one another, therefore, the published limits cannot be straightforwardly applied to model predictions. We present a method to determine a rigorous upper limit on the WIMP-nucleon interaction strength including all possible interferences among operators. We illustrate the method using the null search results from the XENON1T and the PICO collaborations; for some interactions, the limits on the coupling strengths are relaxed up to one order of magnitude. We also present a method that allows to combine the results from different experiments, thus exploiting the synergy between different targets in exploring the parameter space of WIMP-nucleon interactions.
Speaker: Anja Brenner (Max-Planck-Institut für Physik and TUM) -
17:45
Atomic Compton scattering effect on direct dark matter detection 15m
Atomic Compton scattering effect significantly contributes to low-energy electronic recoils below its k-shell energy for the direct dark matter detection. Searches on ADM models, dark photon models, leptophilic dark matter models as well as the conventional WIMPs for background understandings are vitally required to clarify the effect. We employed the relativistic impulse approximation (RIA) together with the ab initio Multiple-configuration Dirac-Fock theory to obtain the atomic Compton scattering [1] for Germanium (Ge) Silicon (Si) and Xenon(Xe) atoms. Comparisons on low momentum transfer regions with our calculations for Ge and Si are achieved. [2] In addition, millicharged dark matter particles estimated by RIA in the atomic ionization for Ge and Xe has been evaluated. [3] A factor-of-two discrepancy on the incoherent-scattering factor(Scattering Function) near 100 eV momentum transfer with the Ge system between our calculation and the latest version of Geant4 simulation data is observed. Plans on the experimental verification and the perspectives of the atomic Compton scattering effect for the direct detections will be discussed.
[1]C.K.Qiao et al., Journal of Physics B: Atomic, Molecular and Optical Physics, 53(07), 075002 (2020)
[2] C.K.Qiao et al., Journal of Physics G 47, 4, 045202(2020)
[3] C.K.Qiao et al., Journal of High Energy Physics, 03, 184 (2021)Speaker: Chang-Hao Fang (Sichuan University) -
17:45
Atomic Many-body Approaches for Constraining DM-electron Interactions 15m
Detectors with low thresholds for electron recoil (ER) open a new window to direct searches of sub-GeV dark matter (DM) candidates. These experimental studies need important theory inputs: the DM scattering rates at detectors through some assumed DM-electron interactions. In this talk, I will present the results of our study on DM-atom scattering through DM-electron interactions at leading order in the context of effective field theory. Our atomic many-body approach is properly benchmarked by atomic data involving not only bound but also continuum states, with a conservative 20% error estimate for DM-xenon and DM-germanium scattering with ER above 12 and 80 eV, respectively. Compared with conventional approaches based on non-relativistic, independent-particle frameworks, the importance of relativistic effects and many-body correlation will be highlighted and discussed.
Speaker: Chih-Pan Wu (Université de Montréal) -
17:45
Crystal responses to general dark matter-electron interactions 15m
In this work we develop a formalism to describe the scattering of dark matter (DM) particles by electrons bound in crystals for general forms of non-relativistic DM-electron interactions. Our novel response to the study of DM-electron interactions allows probing DM with mass down to a fraction of an MeV in a model independent way.
Using a state of the art DFT calculation we apply our formalism to the cases of silicon and germanium, materials currently being used in direct detection experiments. We are thus able to predict the rate of electron excitations to the conduction band, and use this to compute exclusion limits for the strength of DM-electron interactions based on the null-results of the SENSEI and EDELWEISS experiments.
Speaker: Einar Urdshals (Chalmers) -
17:45
Dark Matter Search with the Nuclear Isomer Ta-180m 15m
There is compelling cosmological and astrophysical evidence of dark matter comprising 27% of the energy budget of the Universe. However, dark matter has never been observed in direct detection experiments. The long-time favorite model of Weakly Interacting Massive Particles saw a large experimental effort with steady progress over recent decades. Since also these large-scale searches remain unsuccessful to date, it is compelling to look at more exotic dark matter models which can be constrained with new approaches and much less scientific resources. Using nuclear isomers is one of these approaches.
Ta-180m is the rarest known isotope and the longest-lived meta-stable state whose half-life limits are on the order of $10^{16}$ yr. We investigate how strongly interacting dark matter collides with Ta-180m, leading to its de-excitation. The energy stored in the meta-stable state is released in the transition, which becomes the signature for thermalized dark matter in a well-shielded underground experiment.
We report on a direct detection experiment searching for these dark-matter-induced decay signatures. This search has further constrained open parameter space of cross-section, mass, and component fraction of strongly interacting dark matter. We also propose an indirect geological experiment to search for decay products of Ta-180m in tantalum minerals accumulated over 1 billion years.
Speaker: Bjoern Lehnert (Berkeley Lab) -
17:45
Direct detection of light dark matter from evaporating primordial black holes 15mSpeaker: Marco Chianese (University of Naples Federico II)
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17:45
Direct detection of non-galactic light dark matter 15m
A fraction of the dark matter in the solar neighborhood might be composed of non-galactic particles with speeds larger than the escape velocity of the Milky Way. The non-galactic dark matter flux would enhance the sensitivity of direct detection experiments, due to the larger momentum transfer to the target.
In this note, we calculate the impact of the dark matter flux from the Local Group and the Virgo Supercluster diffuse components in nuclear and electron recoil experiments. The enhancement in the signal rate can be very significant, especially for experiments searching for dark matter induced electron recoils.
Speaker: Gonzalo Herrera (Technical University of Munich, Max-Planck Institute for Physics) -
17:45
Paleo-Detectors - Digging for Dark Matter (and Neutrinos) 15m
Paleo-Detectors are natural minerals which record damage tracks from nuclear recoils over geological timescales. Minerals commonly found on Earth are as old as a billion years, and modern microscopy techniques may allow to reconstruct damage tracks with nanometer scale spatial resolution. Thus, paleo-detectors would constitute a technique to achieve keV recoil energy threshold with exposures comparable to a kiloton-scale conventional "real-time" detector. In this talk, I will discuss the potential of paleo-detectors for the direct detection of dark matter as well as for detecting low-energy neutrinos as are e.g. emitted by core collapse supernovae or our Sun. Furthermore, the age of the minerals provides the ability to look back across Gyr-timescales, giving paleo detectors the unique ability to probe changes in the cosmic ray rate or the galactic supernova rate over such timescales as well as dark matter substructure Earth might have encountered during its past few trips around our Galaxy.
Speaker: Sebastian Baum (Stanford University) -
17:45
Solar reflection of sub-GeV dark matter 15m
Direct detection experiments are searching for rare interactions between dark matter (DM) particles and ordinary matter. If the mass of these dark particles is too low, their kinetic energy does not suffice to trigger these detectors leaving them incapable to observe DM. Processes that boost DM particles can therefore extend the observational reach of direct DM searches to lower masses. I will discuss the mechanism and phenomenology of solar reflection, where DM particles get accelerated via a collision with a solar electron or nucleus. Compared to standard halo DM, solar reflection not only allows to probe lighter masses, a solar reflection signal would also feature a novel modulation signature.
Speaker: Timon Emken (Stockholm University)
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Discussion Panel Dark Matter 9
Chair: Roberto Santorelli
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17:10
Circular polarisation of gamma rays as a probe of dark matter-cosmic ray electron interactions 15m
Dark Matter (DM) constitutes most of the matter in the presently accepted cosmological model for our Universe. However, despite the increased sensitivity of direct and indirect DM searches, and the latest LHC run at 13 TeV centre of mass energy, no signal from DM particles has been detected so far, leading to exclusion limits on the parameter space of DM models. Conventional indirect searches look for an excess in the electromagnetic emission from the sky that cannot be attributed to known astrophysical sources, but polarisation is so far not being explored.
In this talk, I will argue that the photon polarisation is an important feature to understand new physics interactions. In particular, circular polarisation can be generated from Beyond the Standard Model (BSM) interactions if they violate parity and there is an asymmetry in the number of particles which participate in the interaction. I will consider a simplified model for fermionic (Majorana) DM and study the circularly polarised gamma rays below 10 GeV from DM cosmic ray electron interactions. I will study the differential flux of positive and negative polarised photons from the Galactic Centre and show that the degree of circular polarization can reach up to 90%. Finally, I will discuss the detection prospects of this signal in future experiments.
Speaker: Marina Cermeño Gavilán (UCLouvain (CP3)) -
17:25
Dynamical mass measurements and the local dark matter density—recent developments and challenges 15m
Dynamical mass measurements inform us of the local dark matter density, which is a crucial quantity for direct and indirect dark matter searches. Thanks to the Gaia mission, the kinematics of the Milky Way are mapped with a greater depth and precision than ever before. Despite this, a strong consensus has not emerged regarding our galaxy’s gravitational potential and matter density distribution. Gaia has highlighted non-stationary dynamics that bias traditional methods that are based on the assumption of a steady state (e.g. Jeans modelling). Furthermore, uncertainties of the baryonic distribution are still significant. We review recent progress and challenges in this field. We also highlight a couple of alternative methods that are not contingent on the assumption of stationarity, for example a new method for weighing the galactic disk using the phase-space spiral that was discovered with Gaia. A better understanding and modelling of the Milky Way’s time-varying dynamics will improve the precision and accuracy of local dark matter density determinations.
Speaker: Axel Widmark (Niels Bohr Institute, Copenhagen University) -
17:40
Integral X-ray constraints on sub-GeV dark matter 15m
Dark matter (DM) in cosmic structures is expected to produce signals originating from its particle physics nature, among which the electromagnetic emission represents a relevant opportunity. One of the major candidates for DM are weak-scale particles, however no convincing signal of them has been observed so far. For this reason, alternative candidates are getting increasing attention, notably sub-GeV particles, which are the subject of our work. The challenge in indirect detection of sub-GeV DM is that there is scarcity of competitive experiments in the energy range between 1 MeV and hundreds of MeV, hence we need to find alternative ways to study DM candidates with mass in this energy window. In our work we proposed to look at energies much lower than the mass of the sub-GeV DM particles by including the contribution from Inverse-Compton scattering in the total flux. In particular, the electrons and positrons produced by DM particles give rise to X-rays by upscattering the low-energy photons of the radiation fields in the Galaxy (CMB, infrared from dust, optical starlight). These X-rays fall in the energy range covered by the INTEGRAL data, which we used to determine conservative bounds on the DM annihilation cross-section. We considered three annihilation channels: electron, muon and pion. As a result, we derived competitive constraints for DM particles with a mass between 150 MeV and 1.5 GeV.
Speaker: Elena Pinetti (University of Turin, INFN & Sorbonne University) -
17:45
A search for dark matter using sub- PeV gamma-rays observed by Tibet ASγ 15m
The discovery of diffuse sub-PeV gamma-rays by the Tibet ASγ collaboration promises to revolutionize our understanding of the high-energy astrophysical universe. It has been shown that this data broadly agrees with prior theoretical expectations. We study the impact of this discovery on a well-motivated new physics scenario: PeV-scale decaying dark matter (DM). Considering a wide range of final states in DM decay, a number of DM density profiles, and numerous astrophysical background models, we find that this data provides the most stringent limit on DM lifetime for various Standard Model final states. In particular, we find that the strongest constraints are derived for DM masses in between a few PeV to few tens of PeV. Near future data of these high-energy gamma-rays can be used to discover PeV-scale decaying DM.
Speaker: Tarak Maity (Centre for High Energy Physics, Indian Institute of Science, Bengaluru, Karnataka 560012, India) -
17:45
Multi-messenger constraints on the dark matter interpretation of the Fermi-LAT Galactic center excess 15m
The excess of gamma rays in the data measured by the Fermi Large Area Telescope from the Galactic center region is one of the most intriguing mysteries in Astroparticle Physics. This Galactic center excess (GCE), has been measured with respect to different interstellar emission models, source catalogs, data selections and techniques. Although several proposed interpretations have appeared in the literature, there are no firm conclusions as to its origin. The main difficulty in solving this puzzle lies in modeling a region of such complexity and thus precisely measuring the characteristics of the GCE. In this presentation I will show the results obtained for the GCE by using 11 years of Fermi-LAT data, state of the art interstellar emission models, and the newest 4FGL source catalog to provide precise measurements of the energy spectrum, spatial morphology, position, and sphericity of the GCE. I will also present constraints for the interpretation as dark matter particle interactions using the GCE, a gamma-ray analysis of dwarf spheroidal galaxies with LAT data and AMS-02 cosmic-ray antiprotons and positrons flux data.
Speaker: Mattia Di Mauro (INFN Torino) -
17:45
Multi-messenger lifetime constraints on heavy decaying dark matter 15m
Dark matter is one of the cornerstones of the standard cosmological model although we do not know its fundamental nature. Huge effort has been made in order to perform a direct detection of this dark matter component but up to now we have only seen it interacting gravitationally. In this regard the indirect detection is a promising method to search for dark matter, where we try to look at signatures of the dark matter on the astrophysical messengers.
One of the best known astrophysical messengers are the gamma-rays. At very-high energies gamma-rays suffer from absorption, leaving the galactic prompt gamma-ray component as the dominant one. In this work we will adopt the prompt flux as the total one.
Heavy dark matter with $m_\mathrm{DM}>10^7~\mathrm{GeV}$ leads to higher fluxes in the decaying scenario rather than the annihilating one. In this work we focus on heavy decaying dark matter particles and we revisit the dark matter lifetime bounds placed by the gamma-ray measurements by means of the spectra provided by the recent code HDMSpectra. We provide lifetime limits for dark matter particles with $m_\mathrm{DM}=[10^7-10^{15}]~\mathrm{GeV}$ for a set of decay scenarios, where we include the current measurements that provide upper limits on the gamma-ray flux.Speaker: Rasmi Enrique Hajjar Muñoz (SSM (Università di Napoli) - IFIC (CSIC-UV)) -
17:45
Probing the dark matter of a three-loop radiative neutrino mass generation model with the Cherenkov Telescope Array 15m
We investigate the prospect of detecting the dark matter (DM) candidate in the three-loop radiative neutrino mass generation model extended with large electroweak multiplets of the Standard Model (SM) gauge group, at the future imaging atmospheric Cherenkov telescope known as the Cherenkov Telescope Array (CTA). We find that the addition of such large electroweak multiplets leads to a sizable Sommerfeld enhanced annihilation of the DM with an O(TeV) mass, into the SM gauge bosons, which results in continuum- and line-like spectra of very high-energy (VHE) gamma rays, and therefore becomes observable for the CTA. We determine the viable models by setting the upper limit on the SU(2)L isospin of the multiplets from the partial-wave unitarity constraints and the appearance of a low-scale Landau pole in the gauge coupling. Afterwards, by considering the continuum VHE gamma rays produced from the DM annihilation at the Galactic Center, we probe the parameter space of the model using the sensitivity reach of the CTA.
Speaker: Talal Ahmed Chowdhury (University of Dhaka) -
17:45
Search for dark matter annihilation signals from unidentified Fermi-LAT objects with H.E.S.S. 15m
Milky Way-sized galaxies harbor a population of unmerged dark matter subhalos, as shown from cosmological N-body simulations. These subhalos could shine in gamma-rays and be eventually detected as unidentified sources in gamma-ray surveys. From a thorough selection of unidentified Fermi-LAT Objects (UFOs), we observe four UFOs with H.E.S.S. and we search for very high-energy (VHE, E ≥ 100 GeV) gamma-ray emission. Considering dark matter masses above a few hundred GeV, the observed UFOs could be identified as dark matter subhalos, given their hard gamma-ray spectra in the few-ten-to-hundred GeV energy range. Since no significant very-high-energy gamma-ray emission is detected in any of the four UFOs dataset nor in the combined one, we derive constraints on the product of the velocity-weighted annihilation cross-section <$\sigma$ v> by the J-factor for the dark matter models. We derive 95% CL upper limits on <$\sigma$ v>J in W$^+$W$^-$ and $\tau^+$$\tau^-$ annihilation channels for the TeV dark matter particles. Considering thermal WIMPs, we derive constraints on the J-factors from the H.E.S.S. observations. Assuming model-dependent predictions from cosmological N-body simulations on the J-factor distribution for Milky Way-sized galaxies, the dark matter models with masses greater than 0.3 TeV for the UFO emissions can be ruled out at high confidence level.
Speaker: Alessandro Montanari (CEA Saclay / Irfu-DPhP - Université Paris Saclay) -
17:45
Search for dark matter signals toward the irregular dwarf galaxy WLM with H.E.S.S. 15m
Cosmological and astrophysical probes suggest that dark matter (DM) makes up for 85% of the total matter of the Universe. The determination of its nature, however, remains one of the greatest challenges of fundamental Physics. In the DM indirect detection framework, Weakly Interacting Massive Particles (WIMPs) particles would produce signals by self-annihilating and creating SM products such as γ rays, which might be detected by ground-based telescopes. Dwarf irregular galaxies represent promising targets for the search for DM as they are assumed to be dark matter dominated. These dwarf irregular galaxies are rotationally supported with relatively simple and well measured kinematics which lead to small uncertainties on their dark matter distribution profiles. In 2018, the H.E.S.S. telescopes observed the irregular dwarf galaxy Wolf-Lundmark-Melotte (WLM) for 18 hours. These observations are the very first ones made by an imaging air Cherenkov telescope toward this kind of objects. We search for a DM signal looking for excess of γ rays towards WLM dwarf galaxy. We perform the first analysis of this source in stereoscopy using the data taken by the five H.E.S.S. telescopes. We present the new results on the observations of WLM interpreted in terms of velocity-weighted cross section for DM self-annihilation ⟨σv⟩ as a function of DM particle mχ mass for eight annihilation channels: b ̄b, W+W−, τ+τ−, Z+Z−, e+e−, μ+μ−, tt ̄as continuum spectra and the prompt emission γγ .
Speaker: Celine Armand (Astronomy department, University of Geneva) -
17:45
Search for gamma-ray line emission from Dark Matter annihilation in the Galactic Centre with the MAGIC telescopes 15m
We present the search for dark matter (DM) spectral lines in the Galactic centre (GC) region with the MAGIC telescopes. The MAGIC telescopes, located on the Canary island of La Palma (Spain), are sensitive to photons in the energy range from 50 GeV to 50 TeV with low zenith angle observations. MAGIC has performed indirect DM searches with various astrophysical targets. Since the MAGIC telescopes are located in the northern hemisphere, the GC is visible only at high zenith angles. Observations at high zenith angles significantly increase the telescopes' effective collection area, which boosts sensitivity for gamma rays in the TeV regime. We report the results obtained with more than 200 hours of high zenith angle observations of the GC region with MAGIC.
Speaker: Tomohiro Inada (ICRR, UTokyo) -
17:45
Searching for dark matter subhalos with the Fermi-LAT 15m
ΛCDM predicts the existence of dark matter (DM) subhalos, most of them not massive enough to retain gas (i.e., baryons) and become visible. If DM is composed of Weakly Interacting Massive Particles (WIMPs), we expect them to annihilate in subhalos, producing gamma rays which can be detected with the Large Area Telescope (LAT) onboard the Fermi satellite, and appearing as unidentified sources (unIDs) in the gamma-ray sky. We characterize the LAT sensitivity to DM and compare the sample of unIDs in LAT catalogs - previously filtered according to the expected DM annihilation signal - to predictions from the Via Lactea II (VL-II) N-body cosmological simulation, repopulated with low-mass subhalos below its mass resolution limit. This exercise allows us to place conservative and robust constraints on the annihilation cross section vs. WIMP mass parameter space. A spectral and spatial dedicated analysis is then performed for the best DM subhalo candidates, using a decade of Fermi-LAT data. Finally, we also quantify whether spatial extension is, as often claimed, a “smoking gun” for DM subhalo detection, by simulating the LAT response to extended subhalos. This talk will be based on [1906.11896, 1910.14429] and ongoing work within the Fermi-LAT collaboration.
Speaker: Javier Coronado-Blázquez (IFT UAM CSIC) -
17:45
Shedding light on low-mass subhalo survival with numerical simulations 15m
In this work, we carry out a suite of specially-designed numerical simulations that employ a supercluster computational power to shed further light on dark matter (DM) subhalo survival at mass scales relevant for gamma-ray DM searches, a topic subject to intense debate nowadays. Specifically, we have employed a GPU N-body code to study the evolution of low-mass subhalos inside a Milky Way-like halo with unprecedented accuracy, paying particular attention to subhalos at the solar galactocentric radius. We have simulated subhalos with varying mass, concentration, and orbital properties, and considered the effect of the gravitational potential of the Milky-Way galaxy itself. These results provide detailed predictions that will aid current and future quests for the nature of dark matter.
Speaker: Alejandra Aguirre-Santaella (IFT UAM-CSIC)
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Discussion Panel Gravitational Waves 3
Chair: Isabel Cordero-Carrión
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FCF formulation of Einstein equations: local uniqueness and numerical accuracy and stability 15m
We present Einstein equations in the so-called Fully Constrained Formulation (FCF). This formulation has two different sectors: the elliptic sector formed by the Hamiltonian and Momentum constraints together with the equations derived from the gauge choice, and the hyperbolic sector which encodes the evolution of the rest of degrees of freedom of the spacetime metric including the gravitational waves. We present a modification of both sectors that keeps local uniqueness properties but has a better behaviour regarding the relativistic expansion of the equations. We also comment on numerical properties of this reformulation and some potential applications.
Speaker: Samuel Santos-Pérez (Universitat de València) -
17:25
All-sky search in early O3 LIGO data for continuous gravitational-wave signals from unknown neutron stars in binary systems 15m
Rapidly spinning neutron stars are promising sources of persistent gravitational waves. Detecting such a signal would allow probing of the physical properties of matter under extreme conditions. A significant fraction of the known pulsar population belongs to binary systems. Searching for unknown neutron stars in binary systems requires specialized algorithms to address unknown orbital frequency modulations. We present a search for continuous gravitational waves emitted by neutron stars in binary systems in early data from the third observing run of the Advanced LIGO and Advanced Virgo detectors using the semicoherent, GPU-accelerated, BinarySkyHough pipeline. The search analyzes the most sensitive frequency band of the LIGO detectors, 50 - 300 Hz. Binary orbital parameters are split into four regions, comprising orbital periods of 3 - 45 days and projected semimajor axes of 2 - 40 light-seconds. No detections are reported. We estimate the sensitivity of the search using simulated continuous wave signals, achieving the most sensitive results to date across the analyzed parameter space.
Speaker: Rodrigo Tenorio (Universitat de les Illes Balears) -
17:40
Search for long-duration transient gravitational waves from glitching pulsars during LIGO-Virgo third observing run 15m
Pulsars are spinning neutron stars which emit an electromagnetic beam. We expect pulsars to slowly decrease their rotational frequency. However, sudden increases of the rotational frequency have been observed from different pulsars. These events are called “glitches”, and they are followed by a relaxation phase with timescales from days to months. Gravitational waves (GWs) emission may follow these peculiar events. We give an overview of an analysis of GW data from the Advanced LIGO and Virgo third observing run (O3) searching for transient GW signals lasting hours to months after glitches in known pulsars during the 2019-2020 run period. The search method consists of placing a template grid in frequency-spindown space with fixed grid spacings. Then, for each point we compute the transient F-statistic which is maximized over a set of transient parameters like the duration and start time of the potential signals. A threshold on the detection statistic is then set, and we search for peaks over the parameter space for each candidate.
Speaker: Luana Modafferi (Universitat de les Illes Balears) -
17:45
Looking for Core-Collapse Supernovae with Gravitational Waves and Low-energy Neutrinos 15m
Core-collapse supernovae are fascinating astrophysical objects for multimessenger studies. Gravitational waves (GWs) are expected to play a role in the supernova explosion mechanism, however their complex modelling makes the detection very challenging. Low-energy neutrinos will be emitted enormously during the core-collapse explosion and can help for the gravitational wave counterpart search. In this work we develop a multi-messengers strategy to search for such astrophysical objects by exploiting a global network of both low-energy neutrino and gravitational wave detectors. We also improve the detection potential of the neutrino sub-network by exploiting the temporal behaviour of a neutrino burst from a core-collapse supernova. We show that with the proposed approach neutrino detectors can gain at least 10% of detection efficiency at the distance where their efficiency drops. Then, we combine the information provided by GW and neutrino in a multi-messenger strategy. In particular, we obtain an increase of the probability to detect the GW signal from a CCSN at 60 kpc from zero when using only GW analysis to ∼33% with our combined GW-ν approach.
Speaker: Giulia Pagliaroli (INFN) -
17:45
Preparing for the future gravitational wave burst searches with machine learning techniques 15m
Generic searches for gravitational wave bursts are a powerful discovery tool and in the near future they are expected to unveil new phenomena. The coherentWaveBurst (cWB) pipeline is a state-of-the-art burst search pipeline, and it has been used to analyze the data from the latest observing runs of the LIGO/Virgo detectors.
In preparation for the next observing run, which will include KAGRA detector, we are investigating several improvements involving also the application of cutting edge machine learning techniques. A decision tree algorithm will address the post production analysis of the candidate events, upgrading the selection criteria and ranking procedures applied so far. Moreover, an autoencoder neural network will pinpoint morphologies associated to well known noise transients, mitigating their impact.
We show that both these procedures are robust and do not limit the general character of the search. We present preliminary results on public LIGO-Virgo data for widely different burst morphologies, ranging from extreme ad-hoc signals to more astrophysically inspired gravitational-wave transients.Speaker: Sophie Bini (Univ. Trento)
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Discussion Panel HE astrophys. & CRs/Multi-messenger astronomy 3
Chair: Miguel Ángel Velasco
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Status and prospects of the CRAFFT project for the next generation UHECR observation 15m
Recent observations by TA and Auger have advanced our understanding of ultra-high energy cosmic rays, but their origin is still unclear. As a future approach, it will be effective to obtain the directional energy spectra and compositional distributions by observing even larger statistics, and there are active discussions on future large-scale experiments. In order to realize such a huge observation area, the Cosmic Ray Air Fluorescence Fresnel lens Telescope (CRAFFT) project has started to develop a cost-effective fluorescence telescope with Fresnel lenses. We have succeeded in observing cosmic ray induced air showers by simultaneous observations with TA using prototype telescope, and the cost has reached 1/10 of the existing fluorescence telescopes. The progress of the development of autonomous observation system and improved telescope, the performance of event reconstruction, the configuration and analysis results of the test observation, and future prospects will be discussed.
Speaker: Daisuke Ikeda (Kanagawa University) -
17:45
Constraining positron emission from pulsar populations with AMS-02 data 15m
The cosmic-ray flux of positrons ($e^+$) is measured with high precision by the space-borne particle spectrometer AMS-02. The hypothesis that pulsar wind nebulae (PWNe) can significantly contribute to the excess of the $e^+$ cosmic-ray flux has been consolidated after the observation of a $\gamma$-ray emission at TeV energies of a few degree size around Geminga and Monogem PWNe.
In this work we simulate Galactic pulsars populations adopting different distributions for their position in the Galaxy as well as their intrinsic physical properties, in order to overcome the incompleteness of the ATNF catalogue. We fit the $e^+$ AMS-02 data together with a secondary component due to collisions of primary cosmic rays with the interstellar medium. We find that several mock galaxies have a pulsar population able to explain the observed $e^+$ flux, characterized by few, bright sources. We determine the physical parameters of the sources dominating the $e^+$ flux, and assess the impact of different assumptions on radial distributions, spin-down properties, propagation scenarios and $e^+$ emission time.Speaker: Luca Orusa (Turin U. and INFN) -
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Cosmic Ray Light Nuclei Isotopes Measured by the Alpha Magnetic Spectrometer on the ISS 15m
Precise knowledge of the spectra of secondary cosmic-ray isotopes provides a powerful tool to constrain cosmic-ray propagation models. In particular, $^3$He isotopes in cosmic rays are produced by interactions of primary $^4$He with the interstellar medium; similarly, lithium and beryllium are mainly produced by the fragmentation of heavier primary cosmic-ray nuclei. Among light isotopes, the radioactive $^{10}$Be, which has half-life comparable to the cosmic-ray residence time in the Galaxy, provides crucial complementary information. We present precision measurements of the fluxes of helium isotopes, $^3$He and $^4$He, lithium isotopes, $^6$Li and $^7$Li, and beryllium isotopes, $^7$Be, $^9$Be and $^{10}$Be, as well as the time dependence of the $^3$He/$^4$He flux ratio, based on data collected by AMS on the International Space Station.
Speaker: Jiahui Wei (Université de Genève) -
17:45
New Properties of Secondary Cosmic Rays observed by the Alpha Magnetic Spectrometer on the International Space Station 15m
Precise knowledge of the rigidity dependence of secondary cosmic ray fluxes and of secondary-to-primary flux ratios is essential in the understanding of cosmic ray propagation. We report the properties of light secondary cosmic-ray lithium, beryllium , boron nuclei, and heavy secondary cosmic ray fluorine nuclei in the rigidity R range 2 GV to 3 TV observed by the Alpha Magnetic Spectrometer experiment on the International Space Station. The secondary-to-primary ratios fluorine-to-silicon and boron-to-oxygen (or boron-to-carbon) will be discussed, showing that the propagation properties of heavy cosmic rays, from fluorine to silicon, are different from those of light cosmic rays, from helium to oxygen. The properties of cosmic-ray sodium and aluminum nuclei, which are partly secondary and partly primary, will also be presented.
Speaker: Yao Chen (Shandong Institute of Advanced Technology (SDIAT)) -
17:45
On the interpretation of the latest AMS-02 cosmic ray electron spectrum 15m
The latest AMS-02 data on cosmic ray electrons show a break in the energy spectrum around 40~GeV, with a change in the slope of about 0.1. We perform a combined fit to the newest AMS-02 positron and electron flux data above 10 GeV using a model where sources include production of pairs from pulsar wind nebulae (PWNe), electrons from supernova remnants (SNRs) and both species from spallation of hadronic cosmic rays with interstellar medium atoms.
We demonstrate that the change of slope in the AMS-02 electron data is well explained by the interplay between the flux contributions from SNRs and from PWNe. In fact, the relative contribution to the data of these two populations changes by a factor of about 13 from 10 to 1000~GeV. The PWN contribution has a significance of at least $4\sigma$, depending on the model used for the propagation, interstellar radiation field and energy losses.
The effect of the energy losses alone, when the inverse Compton scattering is properly computed within a fully numerical treatment of the Klein-Nishina cross section, cannot explain the break in the $e^-$ flux data, as recently proposed in the literature.Speaker: Fiorenza Donato (Torino University & INFN) -
17:45
Precision Measurement of Cosmic Ray Deuterons with the Alpha Magnetic Spectrometer 15m
Deuterons are the most abundant of secondary cosmic rays and represent a few percent of the single-charged cosmic-ray nuclei. Cosmic-ray deuterons are expected to be produced by fragmentation of primary cosmic-ray Helium with the interstellar medium. Therefore, a good knowledge of the deuteron abundance and energy dependence provides essential information to verify and constrain cosmic-ray propagation models. Precision measurements of deuteron flux in the rigidity range from 2 to 20 GV as well as deuteron-to-proton flux ratio performed by the Alpha Magnetic Spectrometer during the first 8.5 years onboard the International Space Station will be presented.
Speaker: Diego Mauricio Gomez Coral (University of Hawaii at Manoa) -
17:45
The High-Energy Particle Detector capabilities in the measurement of proton and electron fluxes along the China Seismo-Electromagnetic Satellite orbits 15m
CSES-01 (China Seismo-Electromagnetic Satellite) is a multi-instrumental space mission developed by CNSA (Chinese National Space Administration) and ASI (Italian Space Agency) to investigate the near-Earth electromagnetic, plasma, and particle environment, focusing on the perturbations induced by natural sources and anthropocentric emitters. The Italian High-Energy Particle Detector (HEPD-01) onboard CSES-01, made of two planes of silicon tracker and a calorimeter of plastic scintillators and LYSO inorganic crystals, provides precise measurements for electrons of 3-100 MeV, protons of 30-200 MeV, and light nuclei. The good capabilities in the detection of particles, combined with a very large detector acceptance and with the CSES-01 polar orbit, make HEPD-01 well suited for many different purposes. These include measurements of the primary cosmic ray spectra, the trapped proton spectra inside the South Atlantic Anomaly, and the re-entrant albedo all-electrons fluxes. In this work, we present the data-analysis techniques and the different approaches used to provide measurements of the different particle populations detected along the CSES-01 orbits. Some of the recent HEPD-01 results are presented and compared with models, as the NASA AP9, which provides predictions of high-energy proton spectra in the radiation belts, or the HelMod model, used to simulate the solar modulation effects of cosmic rays in the heliosphere.
Speaker: Alessandro Sotgiu (INFN - section of Rome "Tor Vergata") -
17:45
Update on the characterisation of the pGCT, a 4m-prototype telescope built as part of the Cherenkov Telescope Array project 15m
The Gamma-ray Cherenkov Telescope prototype (pGCT) is a prototype of an Imaging Atmospheric Cherenkov Telescope, developed as Small-Sized Telescope (SST) of 4m during the preparation of the Cherenkov Telescope Array (CTA). Based on a Schwarzschild-Couder dual-mirror optical design providing an optimised Point Spread Function (PSF) on a wide field, it had its first Cherenkov light on the Meudon site of the Observatoire de Paris in 2015. Since the decision of CTA to harmonize its future SSTs, the pGCT instrument and the experience gained with its development are now used by the Observatoire de Paris team to provide a test bench for Cherenkov astronomy and a pedagogical tool for educational purposes in Meudon. This paper briefly describes the design of the pGCT and presents the lastest advances in the optics of the prototype and its characterisation, directly related to the implementation of new high-quality metallic mirrors carried out since 2020.
Speaker: Emma Rébert (Observatoire de Paris GEPI) -
17:45
Using PIC and PIC-MHD to model the interaction between an electron-positron beam and a thermal plasma 15m
The origin of the gamma-ray halo around pulsars is associated with the reduced diffusivity of energetic particles responsible for gamma-ray emission with respect to the mean-free path they adopt in the interstellar medium. A possible explanation for this behaviour is that the energetic particles released from the pulsarwind termination shock themselves trigger the turbulence necessary to explain this reduced diffusivity (Evoli et al 2018).
In order to test the ability of the e-e beam to trigger an efficient streaming instability we are in the process of conducting a series of benchmarking simulations using both PIC and PIC-MHD techniques to follow the evolution of both the electron-positron beam and the thermal background plasma and determine whether the beam can trigger the necessary instabilities.
We find that the passage of the electron-positron beam through the thermal plasma triggers streaming instabilities that lead to local amplification of the magnetic field.Speaker: Allard Jan van Marle (LUPM)
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Discussion Panel Neutrinos 7
Chair: Masaki Ishitsuka
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Time delay distributions of neutrino echoes induced by secret neutrino interactions 15m
We examine the time delay distribution of astrophysical neutrinos as a result of Beyond Standard Model interactions with the cosmic neutrino background. We focus on the case of neutrino-neutrino interactions with a scalar mediator, and develop a framework to handle the sharp increase in the cross section at resonance energy. For a 10 MeV mediator mass and neutrino mass of 0.1 eV, we find that the neutrino characteristic time delay differs from analytic estimates at large optical depths, both in the elastic and inelastic scattering regimes. As an application of our simulations, we assumed an $E^{-2}$ power law spectrum at $z=1$, and found typical delays of 10s--1000s, for neutrinos above 1 TeV, for coupling strengths between 0.01 and 0.2.
Speaker: Jose Carpio (Penn State University) -
17:25
Heavy Dirac/Majorana Fermion Decays 15m
If a heavy neutrino is discovered, determining its nature, i.e., whether it is a Dirac or a Majorana fermion, will be at the top of the list of the next questions to ask. A natural way to determine this is to analyze the particle's decays and to observe whether they violate lepton number. However, if the final state includes any light neutrinos, this is impossible. In that event, we may still be able to determine the nature by measuring the distribution of decay events. I will show how this procedure may be performed in the context of three-body decays of heavy neutrinos into a light neutrino and a pair of charged leptons.
Speaker: Kevin Kelly (Fermilab) -
17:40
The SND@LHC experiment at CERN 15m
SND@LHC is a compact and stand-alone experiment to perform measurements with neutrinos produced at the LHC in a hitherto unexplored pseudo-rapidity region of 7.2 < 𝜂 < 8.6, complementary to all the other experiments at the LHC. The experiment is to be located 480 m downstream of IP1 in the unused TI18 tunnel. The detector is composed of a hybrid system based on an 800 kg target mass of tungsten plates, interleaved with emulsion and electronic trackers, followed downstream by a calorimeter and a muon system. The configuration allows efficiently distinguishing between all three neutrino flavours, opening a unique opportunity to probe physics of heavy flavour production at the LHC in the region that is not accessible to ATLAS, CMS and LHCb. This region is of particular interest also for future circular colliders and for predictions of very high-energy atmospheric neutrinos. The detector concept is also well suited to searching for Feebly Interacting Particles via signatures of scattering in the detector target. The first phase aims at operating the detector throughout LHC Run 3 to collect a total of 150 fb$^{−1}$. The experiment was recently approved by the Research Board at CERN. A new era of collider neutrino physics is just starting.
Speaker: Dario De Simone (Univ Zürich) -
17:45
First Neutron Capture Results of ANNIE 15m
ANNIE is a 26 ton Gd-loaded water Cherenkov detector installed in the Booster Neutrino Beam at Fermilab. It will measure the neutron multiplicity, as a function of momentum transfer, of neutrino-neutron interactions on water. To achieve this, it is imperative that the neutron capture characteristics in the detector volume are well parameterised. This talk will introduce the Americium Beryllium calibration source, highlight its successful deployment, and present the resulting neutron detection efficiency map and measured neutron capture time.
Speaker: Leon Pickard (UC Davis) -
17:45
Generalizing the Scotogenic model 15m
The Scotogenic model is an economical setup that induces Majorana neutrino masses at the 1-loop level and includes a dark matter candidate. We discuss a generalization of the original Scotogenic model with arbitrary numbers of generations of singlet fermion and inert doublet scalar fields. First, the full form of the light neutrino mass matrix is presented, with some comments on its derivation and with special attention to some particular cases. The behavior of the theory at high energies is explored by solving the Renormalization Group Equations.
Speaker: Pablo Escribano Valiente (IFIC (CSIC-Univ Valencia)) -
17:45
Measuring high-energy neutrinos with FASERnu in the LHC Run-3 15m
FASER$\nu$ at the LHC is designed to directly detect collider neutrinos for the first time and study their cross sections at high energies, where no such measurements currently exist. The detector will be located in the far-forward region of ATLAS. Deployment on the beam collision axis maximizes the flux of all three neutrino flavors, and allows FASER$\nu$ to measure their interaction cross-sections in the currently unexplored TeV energy range. For electron and tau neutrinos, these measurements will extend existing cross section measurements to significantly higher energies. In 2018 we performed a pilot run with the aims of measuring particle fluxes at the proposed detector location and of possibly detecting neutrino interactions for the first time at the LHC. We installed a 30-kg lead/tungsten emulsion detector and collected data of 12.2 fb$^{-1}$. The analysis of this data has yielded several neutrino interaction candidates, excluding the no-signal hypothesis at the 2$\sigma$ level. During Run-3 of the LHC starting from 2022, we will deploy an emulsion detector with a target mass of 1.1 tons, coupled with the FASER magnetic spectrometer. This would yield roughly 2,000 $\nu_e$, 8,000 $\nu_{\mu}$, and 50 $\nu_{\tau}$ interacting in the detector. We present the status and prospects of FASER$\nu$, as well as the neutrino detection in the pilot run data.
Speaker: Umut Kose (CERN EP-NU) -
17:45
Neutron Beam Test with a Scintillator Tracker for Long-Baseline Neutrino Experiments 15m
The focus of the long-baseline neutrino oscillation experiments that are currently being built is the precise measurement of the neutrino oscillation parameters which will require good control of the systematic uncertainties including those of the neutrino interaction models. A novel three-dimensional projection scintillation tracker will be the active target of the ND280 near detector upgrade for the T2K experiment and is being considered as one of the on-axis near detector modules for the DUNE experiment. This detector features fine granularity and good timing resolution allowing for better reconstruction of the final state products of neutrino interactions on event-by-event basis including the ability to reconstruct neutrons. Two prototypes took neutron beam data in 2019 and 2020 at the Los Alamos National Lab (LANL) to study the detector response to neutrons with energies from 0 to 800MeV. The details of the detector response calibration and the measurement of the total neutron cross section are presented.
Speaker: Martin Tzanov (Louisiana State University) -
17:45
New Constraints on Heavy Neutral Leptons using the ArgoNeuT Experiment 15m
ArgoNeuT was a 0.24 ton Liquid Argon Time Projection Chamber (LArTPC) detector at Fermilab running from 2009 to 2010. It was located along the NuMI neutrino beam and collected six months of data in anti-neutrino beam mode. ArgoNeuT has performed several first neutrino cross-section measurements on argon, however its dataset can also be used to probe physics beyond the Standard Model. One such model is Heavy Neutral Leptons (HNL) that couple to the standard model via mixing with tau neutrinos. These would be produced by the NuMI beam via decays of D-mesons into secondary taus, which then decay into HNLs. The HNLs then travel along the NuMI beamline and can decay into an active neutrino and a muon and anti-muon pair either within ArgoNeuT or in the cavern upstream of the detector. This talk presents a search for such HNLs with ArgoNeuT and the resulting new constraints on the HNL mass and mixing angles.
Speaker: Patrick Green (The University of Manchester) -
17:45
Nonstandard neutrino Interactions as a solution to the NOvA and T2K tension 15m
The latest data of the two long-baseline accelerator experiments NOvA and T2K, interpreted in the standard 3-flavor scenario, display a tension. A mismatch in the determination of the standard CP-phase delta_CP extracted by the two experiments is evident in the normal neutrino mass ordering. In this talk, we show that such a discrepancy can be resolved if one hypothesizes the existence of complex neutral-current non-standard interactions (NSI) of the flavor changing type.
Speaker: Antonio Palazzo (University of Bari andINFN) -
17:45
Recent neutrino cross-section results from MicroBooNE 15m
MicroBooNE is a liquid argon time projection chamber that operates in the Booster Neutrino Beam at Fermilab. The detector provides high-resolution imaging of neutrino interactions with a low threshold and full angular coverage. Thanks to a high event rate and several years of continuous operation, the MicroBooNE collaboration has obtained the world’s largest dataset of neutrino-argon scattering events. A detailed understanding of these interactions, especially the impact of nuclear physics effects, will be critical to the success of future precision neutrino oscillation efforts, particularly the argon-based Deep Underground Neutrino Experiment (DUNE) and the Short-Baseline Neutrino (SBN) program. This talk presents an overview of the latest neutrino-argon cross section measurements in MicroBooNE, including measurements of protons produced in muon neutrino interactions, measurements of the electron neutrino inclusive cross section, and progress towards measurements of rare channels.
Speaker: Lu Ren (New Mexico State University) -
17:45
Search for exotic neutrino-electron interactions using solar neutrinos in XMASS-I 15m
In recent years, the larger size and lower background of dark matter search detectors have opened up a new frontier of searching for new physics other than dark matter search using these detectors. One of them is the search for new properties of neutrinos by observing the interaction of neutrinos at low energy. XMASS is multi-purpose experiment using single phase liquid xenon (LXe) and is located at the Kamioka Observatory in Japan. We searched for exotic neutrino-electron interactions that could be produced by a neutrino millicharge, by a neutrino magnetic moment, or by dark photons using solar neutrinos in XMASS. We analyzed the data between November 2013 and March 2016 for 711days dataset and no significant signals have been observed with predicting the backgrounds in detector. We obtained an upper limit of neutrino millicharge of $5.4\times10^{-11}$e for all flavors of neutrino. We also set individual flavors which the limits for $\nu_{\mu}$ and $\nu_{\tau}$ are the best direct experimental limits. We also obtain an upper limit for the neutrino magnetic moment of 1.8$\times$10$^{-10} \mu_{B}$. In addition, we obtain upper limits for the coupling constant of dark photons in the $U(1)_{B-L}$ model. This result almost excludes the possibility to understand the muon $g-2$ anomaly by dark photons.
Speaker: Hiroshi Ogawa (Nihon University) -
17:45
Study of tau neutrino production with nuclear emulsion at CERN-SPS 15m
The data on tau neutrino is very scarce, only a few experiments have detected its interactions. At FNAL beam dump experiment DONUT, tau neutrino interaction cross-section was directly measured with a large systematical (~50%) and statistical (~30%) errors. The main source of systematical error is due to a poor knowledge of the tau neutrino flux. The effective way for tau neutrino production is the decay of Ds mesons, produced in proton-nucleus interactions. The DsTau experiment at CERN-SPS has been proposed to measure an inclusive differential cross-section of a Ds production with a consecutive decay to tau lepton in p-A interactions. The goal of experiment is to reduce the systematic uncertainty to 10% level. A precise measurement of the tau neutrino cross section would enable a search for new physics effects such as testing the Lepton Universality (LU) of Standard Model in neutrino interactions. The detector is based on nuclear emulsion providing a sub-micron spatial resolution for the detection of short length and small “kink” decays. Therefore, it is very suitable to search for peculiar decay topologies (“double kink”) of Ds→τ →X. After successful pilot runs and data analysis, CERN had approved the DsTau project as a new experiment NA65 in 2019. During the physics runs, 2.3×10^8 proton interactions will be collected in the tungsten target, and about 1000 Ds→τ decays will be detected. In this talk, the results from the pilot run will be presented and the prospect for physics runs in 2021-2022 will be given.
Speaker: Svetlana Vasina (JINR, Dubna) -
17:45
T2K latest results on neutrino-nucleus cross sections 15m
A detailed understanding of neutrino(ν)-nucleus interactions is essential for the precise measurement of neutrino oscillations at long baseline experiments, such as T2K. The T2K near detector complex, designed to constrain the T2K flux and cross section models, also provides a complementary program of neutrino interaction cross-section measurements. Through the use of multiple target materials (carbon, water, argon, iron, lead), and the ability to sample different neutrino spectra (with detectors located on- and off-axis with respected to the flux), T2K is able to investigate atomic number and energy dependence of interaction cross sections in single experiment. An overview of the T2K measurement strategy, adopted to reduce the model dependence, and the most recent results, as well as future planned analyses, will be presented.
Speaker: Samuel Jenkins -
17:45
The role of leptonic CPV phases in cLFV observables 15m
In models where the Standard Model is extended by Majorana fermions, interference effects due to the presence of
CP violating phases have been shown to play a crucial role in lepton number violating processes.
However, important interference effects can also arise in lepton number conserving, but charged lepton flavour violating (cLFV) transitions and decays.
In this work we show that in the presence of CP violating (Dirac and Majorana) phases important interference effects might arise, with a striking
impact for the predicted rates of cLFV observables.
We explore the interference effects in several cLFV observables, carrying for the first time a thorough analysis of the different observables and the implications for future observation.
We show in this talk how the presence of leptonic CP violating phases might lead to a loss of correlation between observables (typically present in simple SM extensions via heavy sterile fermions),
or even to the suppression of certain channels; these effects can be interpreted as suggestive of non-vanishing phases.Speaker: Jonathan Kriewald (LPC Clermont-Ferrand)
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Discussion Panel Neutrinos 8
Chair: Pau Novella
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Study of Ocean Bottom Detector for observation of geo-neutrinos from the mantle 15m
Observation of anti-neutrinos emitted from radioactive isotopes inside the Earth(geo-neutrinos) bring direct information on the Earth’s chemical composition and its heat balance, which strongly relate to the Earth’s dynamics.
To date, two experiments (KamLAND and Borexino) have measured geo-neutrinos and constrained the range of acceptable models for the Earth’s composition, but distinguishing the mantle flux by land-based detectors is challenging as the crust signal is about 70 % of the total anti-neutrino flux.
Given the oceanic crust is thinner than continental crust and has lower concentration of radioactive elements, geo-neutrino detector in the ocean, Ocean Bottom Detector (OBD), makes it sensitive to geo-neutrinos originating from the Earth’s mantle. Another unique feature of OBD is keeping the distance from the reactors which are the main background sources for land-based detectors. In addition, this movable detector can observe at multiple points in the ocean.
Our working group was jointly constructed from interdisciplinary communities in Japan which include particle physics, geoscience, and ocean engineering. We have started to work on technological developments of OBD.
In this presentation, I present the status of development and future plan.Speaker: Taichi Sakai (Tohoku Univ. Research Center for Neutrino Science) -
17:25
Spectroscopy of geoneutrinos with Borexino 15m
Borexino is a 280-ton liquid scintillator detector located at the Laboratori Nazionali del Gran Sasso (LNGS), Italy and is one of the two detectors that has measured geoneutrinos so far. The unprecedented radio-purity of the scintillator, the shielding with highly purified water, and the placement of the detector at 3800 m w.e. depth have resulted in very low background levels, making Borexino an excellent apparatus for geoneutrino measurements. This talk will summarize the latest geoneutrino analysis with Borexino, using the data obtained from December 2007 to April 2019. The updated statistics and the optimized analysis techniques such as an increased fiducial volume and sophisticated cosmogenic vetoes, have led to more than a factor two increase in exposure when compared to the previous measurement in 2015, resulting in a significant improvement in the precision. In addition, Borexino was also able to reject the null hypothesis of the mantle geoneutrino signal with 99% C.L., for the first time, by exploiting the detailed knowledge of the crust surrounding the detector. This talk will also include other geological interpretations of the obtained results such as the calculation of the radiogenic heat and the comparison of the results to various predictions. Additionally, upper limits for a hypothetical georeactor that might be present at different locations inside the Earth will also be discussed.
Speaker: Sindhujha Kumaran (IKP-2 Forschungszentrum Jülich and RWTH Aachen University) -
17:40
Observation of CNO cycle solar neutrinos in Borexino 15m
The Borexino detector, located at the Laboratori Nazionali del Gran Sasso in Italy, is a radiopure 280 ton liquid scintillator detector with a primary goal to measure low-energy solar neutrinos created in the core of the Sun. These neutrinos are a consequence of nuclear fusion reactions in the solar core where Hydrogen is burned into Helium and provide a direct probe of the energy production processes, namely the proton-proton ($pp$) chain and the Carbon-Nitrogen-Oxygen (CNO) cycle. The fusion of Hydrogen in the case of the CNO cycle, which is expected to contribute in the order of less than $\sim\,1\%$ to the total solar energy, is catalyzed by Carbon, Nitrogen, and Oxygen directly depending on the abundances of these elements in the solar core. Neutrinos from the $pp$ chain have been studied in Borexino with outstanding precision through the measurement of $pp$, $pep$, $^{7}$Be, and $^{8}$B neutrinos over the past decade, while the existence of neutrinos from the CNO cycle have been confirmed recently for the first time with a high statistical significance. The measurement of CNO neutrinos is challenging due to the high spectral correlation with the decay electrons of the background isotope $^{210}$Bi and the $pep$ solar neutrino signal. The experimental achievement of thermal stabilization of the Borexino detector after mid 2016, has opened the possibility to develop a method to constrain the $^{210}$Bi rate through its decay daughter and $\alpha$ emitter $^{210}$Po which can be identified in Borexino with an efficiency close to $100$ percent on an event-by-event basis. Moreover, the flux of $pep$ neutrinos can be constrained precisely through a global analysis of solar neutrino data which is independent of the dataset used for the CNO analysis. This talk is dedicated to the first experimental evidence of neutrinos produced in the CNO fusion cycle in the Sun which is at the same time the dominant energy production mechanism in heavier stars compared to the Sun in the Universe.
Speaker: Oemer Penek (IKP-2 Forschungszentrum Juelich) -
17:45
A New Approach to Probe Non-Standard Interactions in Atmospheric Neutrino Experiments 15m
We propose a new approach to explore the neutral-current non-standard neutrino interactions (NSI) in atmospheric neutrino experiments using oscillation dips and valleys in reconstructed muon observables, at a detector like ICAL that can identify the muon charge. We focus on the flavor-changing NSI parameter $\varepsilon_{\mu\tau}$, which has the maximum impact on the muon survival probability in these experiments. We show that non-zero $\varepsilon_{\mu\tau}$ shifts the oscillation dip locations in $L/E$ distributions of the up/down event ratios of reconstructed $\mu^-$ and $\mu^+$ in opposite directions. We introduce a new variable $\Delta d$ representing the difference of dip locations in $\mu^-$ and $\mu^+$, which is sensitive to the magnitude as well as the sign of $\varepsilon_{\mu\tau}$, and is independent of the value of $\Delta m^2_{32}$. We further note that the oscillation valley in the ($E$, $\cos \theta$) plane of the reconstructed muon observables bends in the presence of NSI, its curvature having opposite signs for $\mu^-$ and $\mu^+$. We demonstrate the identification of NSI with this curvature, which is feasible for detectors like ICAL having excellent muon energy and direction resolutions. We illustrate how the measurement of contrast in the curvatures of valleys in $\mu^-$ and $\mu^+$ can be used to estimate $\varepsilon_{\mu\tau}$. Using these proposed oscillation dip and valley measurements, the achievable precision on $|\varepsilon_{\mu\tau}|$ at 90% C.L. is about 2% with 500 kt$\cdot$yr exposure. The effects of statistical fluctuations, systematic errors, and uncertainties in oscillation parameters have been incorporated using multiple sets of simulated data. Our method would provide a direct and robust measurement of $\varepsilon_{\mu\tau}$ in the multi-GeV energy range.
Speaker: Anil Kumar (Institute of Physics, Bhubaneswar) -
17:45
First Cherenkov directional detection of sub-MeV solar neutrinos in Borexino 15m
Borexino is a 280t liquid scintillator detector at the Laboratori Nazionali del Gran Sasso (LNGS), Italy. Its main goal is the precision spectroscopy of solar neutrinos down to energies of ~190 keV and for this task it features a high radio-purity and a high light yield of ~10,000 scintillation photons per 1 MeV deposited energy. The solar neutrinos are measured by their elastic scattering off electrons which induce isotropically emitted scintillation photons that are detected by PMTs.
In this talk we present the first measurement of solar $^{7}$Be neutrinos using their associated Cherenkov photons in a high light yield scintillation detector. In Borexino electrons with E>160 keV produce Cherenkov photons but the ratio of Cherenkov photons from the neutrino scattered electrons is <1% for all PMT hits. A typical reconstruction of the event direction, as in water Cherenkov detectors, is therefore not possible. In this analysis we look instead at the integrated signal of all PMT hits for all detected events and correlate the position of the hit PMT relative to the reconstruced position of the event with the well known position of the Sun. The angular distribution of these correlated hits shows the statistical contribution of Cherenkov photons from the electrons that were scattered by solar neutrinos. In this analysis, the number of $^{7}$Be neutrinos is then inferred from the measured angle distribution, which is compared to probability density functions produced with the Geant4-based Borexino Monte Carlo simulation. To do that it is necessary to tune the MC Cherenkov time behaviour, which is possible in Borexino with the available $^{54}$Mn and $^{40}$K gamma calibration sources.Speaker: Johann Martyn (Borexino, Johannes Gutenberg-Universität Mainz) -
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Neutrino NSI effects on future solar sector measurements 15m
The next-generation neutrino experiment JUNO will determine the solar oscillation parameters - $\sin^2 \theta_{12}$ and $\Delta m^2_{21}$ - with great accuracy, in addition to measuring $\sin^2\theta_{13}$, $\Delta m^2_{31}$ and the mass ordering. In parallel, the continued study of solar neutrinos at Hyper-Kamiokande will provide complementary measurements in the solar sector. In this talk, I will present the expected sensitivity to non-universal and flavour-changing non-standard interactions (NSI) with $d$-type quarks from the combination of these two future experiments. I will also discuss the robustness of solar oscillation parameter measurements in the presence of NSI and comment on the enduring potential viability of the LMA-D solution.
Speaker: Susana Molina Sedgwick (IFIC (CSIC-Univ Valencia)) -
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Solar Neutrino Detection Sensitivity in DARWIN via Electron Scattering 15m
The proposed liquid xenon observatory DARWIN will exhibit sensitivity to solar neutrinos via elastic electron scattering. In this channel, DARWIN will have the potential to measure the fluxes of five solar neutrino components: $pp$, $^7$Be, $^{13}$N, $^{15}$O and $pep$. The precision of the $^{13}$N, $^{15}$O and $pep$ components is hindered by the double-beta decay of $^{136}$Xe and, thus, would benefit from a depleted target. A high-statistics observation of $pp$ neutrinos would allow for measurements of the electroweak mixing angle, $\sin^2\theta_w$, and the electron-type neutrino survival probability, $P_{ee}$, in the electron recoil energy region from a few keV up to 200 keV for the first time, with relative precision of 5% and 4%, respectively, with 10 live years of data and a 30 tonne fiducial volume. An observation of $pp$ and $^7$Be neutrinos would constrain the neutrino-inferred solar luminosity to 0.2%. A combination of all flux measurements would distinguish between the high- (GS98) and low-metallicity (AGS09) solar models with 2.1-2.5$\sigma$ significance, independent of external measurements from other experiments or a measurement of $^8$B neutrinos through coherent elastic neutrino-nucleus scattering in DARWIN. Finally, it is demonstrated that with a depleted target DARWIN may be sensitive to the neutrino capture process of $^{131}$Xe.
Speaker: Shayne Reichard -
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The Selena Neutrino Experiment 15m
Imaging sensors made from an ionization target layer of amorphous selenium (aSe) coupled to a silicon complementary metal-oxide-semiconductor (CMOS) active pixel array for charge readout are a promising technology for neutrino physics. The high spatial resolution in a solid-state target provides unparalleled rejection of backgrounds from natural radioactivity in the search for neutrinoless 𝛽𝛽 decay and for solar neutrino spectroscopy with $^{82}$Se. We present results on the ionization response of aSe measured from the photoabsorption of 122keV 𝛾 rays in a single-pixel device, and report on the progress in the fabrication and testing of the first prototype imaging sensors based on the Topmetal-II pixelated CMOS charge readout chip. We explore the scientific reach of a large neutrino detector with the proposed technology based on our experimental understanding of the sensor performance.
Speaker: Alvaro E Chavarria (University of Washington)
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Discussion Panel Underground Laboratories 2
Chairs: Aldo Ianni & Jeter Hall
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The LUNA project at Gran Sasso : new results about the early Universe and future perspectives 15m
In the cosmic silence of the Gran Sasso Underground Laboratory, where 1400 m of rock shield the experimental halls from external radiation, the LUNA experiment is able to recreate the processes that occurred during Big Bang Nucleosynthesis (BBN) and the ones that still occur in stars today. Among the reactions recently studied at LUNA there is a key process of BBN: the reaction by which a proton and a nucleus of deuterium fuse together to form $^{3}$He, in symbols: D($p,\gamma$)$^{3}$He. The measurement of this cross section was carried out with a precision of 3% at the energies of interest for the BBN and allowed for a deeper knowledge of the deuterium destruction process and a better evaluation of its primordial abundance. Thanks to this study, it was possible to refine the calculations of the primordial nucleosynthesis and to obtain an accurate determination of the density of ordinary (or “baryonic”) matter, thus providing support to the standard cosmological model.
Presently the LUNA collaboration is continuing its scientific activity at the 400 KV accelerator but, in the next years, a new window will be opened by the acquisition with the new LUNA-MV facility, under installation at LNGS. The new accelerator will be able to provide hydrogen, helium and carbon high current beams up to an accelerating voltage of 3.5 MV and it will allow to explore the helium and carbon burning processes, by studying the key reactions shaping the evolution of massive stars such as $^{12}$C+$^{12}$C, $^{13}$C($\alpha,n$)$^{16}$O and $^{22}$Ne($\alpha,n$)$^{25}$Mg.
The present contribution is aimed to summarise the most recent results achieved by LUNA Collaboration, in particular about the D($p,\gamma$)$^{3}$He process, and to highlight the rich experimental program connected to the new facility.Speaker: Sandra Zavatarelli (INFN - Genova) -
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A Radioacitivity Survey of Commercially Available PTFE from European Suppliers 15m
Due to its optical and electrical properties polytetrafluoroethylene (PTFE) is an important construction material for many rare event searches. The radioactive contamination of PTFE thus needs to be as low as possible. We present a cross-sectional study investigating the radioactive contamination of PTFE samples from major European suppliers of raw PTFE. The bulk contaminations of the samples were measured utilizing ICP-MS and HPGe gamma spectrometry; the radon surface emanation was assessed with an electrostatic radon detector that was recently commissioned in Freiburg.
Speaker: Daniel Baur (University of Freiburg) -
17:40
Measurements and Simulation of background radiation for rare event search experiments at an underground laboratory 15m
Rare event search experiments mostly placed inside underground laboratories demand very accurate measurements of ambient radiation contribution from charged cosmic particles from radioactive decay and nuclear processes in the surrounding rock components. Therefore careful analysis of rock components and specific background measurement experiments along with simulation studies form the first foundation of these types of experiments. To begin with, an underground laboratory for rare event search experiments is set up at 555 m vertical depth inside a mine in India. Gamma rays and neutrons from the environmental rocks, penetrating cosmic muons and secondary particles are the major causes of concern. In this work, we have experimentally measured the fluxes of cosmic muons, ambient gamma rays and the environmental neutrons inside the laboratory. We have also performed detailed simulations using the tracking toolkit of GEANT4 and environmental data to estimate the measured fluxes and related numbers. Very good agreements with the measured fluxes in almost all the cases are found. Based on our studies, we find that while comparing the experimental and the GEANT4 results, it is important to include multiple scattering events to obtain reliable results. Experimental results, simulation strategies followed and the results obtained will be presented.
Speaker: Sayan Ghosh (Saha Institute of Nuclear Physics) -
17:45
Jánossy Underground Research Laboratory 15mSpeaker: Edit Fenyvesi (Wigner Research Centre for Physics)
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17:45
Radioactive Background Characterization of the Cryogenic Underground TEst Facility (CUTE) 15m
The Cryogenic Underground TEst Facility (CUTE) is fully operational in the low-radioactivity environment of the SNOLAB Underground Laboratory. Estimation of the background from radioactive processes via Geant4 simulation is crucial in informing the background budget for the facility. The radioactive background characterization of the CUTE facility will be presented along with the background model validation through comparison with recently acquired data.
Speaker: Silvia Scorza (SNOLAB) -
17:45
Recent development of the radiopurity.org materials database 15m
The radiopurity.org database has proven to be a valuable resource for the low background physics community as a tool to track and share assay results. This talk will describe recent collaborative efforts between the Pacific Northwest National Laboratory and SNOLAB to modernize the database for the community. Improvements to the search utility and data upload methods will be discussed. Installations to support individual physics collaborations (for example DUNE) and assay facilities will be described, as well as ongoing plans to develop and support the database.
Speaker: Christopher Jackson (Pacific Northwest National Laboratory) -
17:45
Studies of bulk 210Po/210Pb contamination in high purity copper for low-background detectors 15m
Surface and bulk contamination with long-lived daughters of $^{222}$Rn is of great interest for most of the experiments looking for rare events. These include detection of low energy solar neutrinos, searches for neutrino-less double beta decay or searches for dark matter. Decays of $^{210}$Pb, $^{210}$Bi and finally $^{210}$Po may contribute significantly to the experiments’ background directly by the generated radiation, or indirectly through e.g. production of neutrons in the (α,n) reactions. The latter is of special interest for the dark matter experiments as the interactions of neutrons are indistinguishable from the interactions of dark matter particles.
Direct detection of the long-lived part of the $^{238}$U chain is necessary because of possible disequilibrium in the chain. One cannot conclude about the $^{210}$Pb-$^{210}$Po specific activities form the $^{226}$Ra or $^{238}$U activities measured with high-sensitivity gamma-ray spectrometers or ICP-MS instruments, respectively.
A method to measure $^{210}$Po in copper will be discussed. Copper, because of its high radio-purity, is widely applied in low-background experiments as a shielding material and it is also often used to fabricate support structures of sensitive detectors. By separation of $^{210}$Po from the bulk material and subsequent counting of its activity it is possible to achieve the detection limit at the level of 10 mBq/kg. For a selected copper sample (material purchased for shielding of low-background gamma spectrometer) a relation between $^{226}$Ra (determined by application of high-sensitivity gamma spectrometry), $^{210}$Po and $^{210}$Pb (specific activity established form the $^{210}$Po decay profile) indicating a strong radioactive disequilibrium, will be discussed.
Speaker: Tomasz Mróz (Marian Smoluchowski Institute of Physics, Jagiellonian Universit) -
17:45
Testing Quantum Mechanics in the cosmic silence 15m
The VIP experiment aims to perform high sensitivity tests of the Pauli Exclusion Principle (PEP) for electrons, and look for a possible small violation.
In Local Quantum Field Theories approach any PEP violating transition is strongly constrained by the Messiah Greenberg Superselection (MGS) rule, which forbids superpositions of states with different symmetry. Such models can then be only tested with open systems. This condition is realised in VIP-2 by introducing “new” electrons in a pre-existing system of electrons, and then testing the resulting symmetry state. The data analyses results from the newest VIP-2 Open Systems data taking will be presented.
It was recently shown that a large class of Quantum Gravity models embeds the violation of PEP, violating the MSG rule, as a consequence of the space-time non-commutativity. High sensitivity tests of PEP violation in closed systems turn then to be the better candidates to put strong experimental limits on the energy scale of the non-commutativity emergence in Quantum Gravity. The results of exploratory studies based a High Purity Germanium (HPGe) Detecors and high radio-purity Roman Pb targets will be shown.The extremely low background environment of LNGS is also suitable for investigating one of the main mysteries of Quantum Mechanics Foundations: the measurement problem. Dynamical collapse models consist in non-linear and stochastic modifications to the Shroedinger dynamics, which induce the collapse with a rate proportional to the mass. The results of our analyses, setting the strongest constrains on the dynamical collapse models, will be presented.
Speaker: Kristian Piscicchia (CREF, LNF (INFN))
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Tribute to Masatoshi Koshiba 15m
Chair: Juan José Hernandez-Rey
Speaker: Takaaki Kajita (ICRR and IPMU, Univ Tokyo) -
14:15
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14:30
Tribute to Samoil Bilenky 15m
Chair: Juan José Hernandez-Rey
Speaker: Carlo Giunti (INFN Turin) -
14:30
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Direct measurements of cosmic rays from space 30m
Chair: Juan José Hernandez-Rey
Speaker: Valerio Formato (INFN - Roma Tor Vergata) -
15:00
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High-energy neutrinos 30m
Chair: Juan José Hernandez-Rey
Speaker: Justin A. Vandenbroucke (Univ Wisconsin) -
15:30
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Break 30m
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Ultra-high energy cosmic rays 30m
Chair: M.D. Rodríguez Frías
Speaker: Silvia Mollerach (Centro Atómico Bariloche, CONICET) -
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Panel on Diversity and Inclusion in Astroparticle Physics 1h
Participants: Alba Fernández-Barral, Kamiel Janssens, Mayly Sanchez, Srubabati Goswami, Summer Blot and Jonas Rademacker
Moderator: Inés Gil Botella
Speakers: Alba Fernández-Barral (CTA Observatory), Inés Gil Botella (CIEMAT), Jonas H. Rademacker (University of Bristol), Kamiel Janssens (Universiteit Antwerpen), Mayly Sanchez (Iowa State University), Srubabati Goswami (Physical Research Laboratory), Summer Blot (DESY-Zeuthen) -
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Closing and Farewell 15m
Chair: José W.F. Valle
Speaker: Nicolao Fornengo (Univ Torino and INFN)
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