17th International Conference on Topics in Astroparticle and Underground Physics (TAUP 2021)

Online conference taup2021@ific.uv.es
Sergio Pastor (IFIC (CSIC-Univ. Valencia)), Mariam Tórtola (IFIC (CSIC-Univ. Valencia))

The biennial TAUP series covers recent experimental and theoretical developments in astroparticle physics by invited plenary review talks and parallel workshop sessions of invited and contributed presentations. The conference will also include a dedicated poster session.

TAUP 2021 is 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.

    • 14:00 14:30
      Welcome and Opening remarks 30m
      Speakers: Mariam Tórtola (IFIC (CSIC-Univ. Valencia)), Sergio Pastor (IFIC (CSIC-Univ. Valencia))
    • 14:30 15:00
      Neutrino theory 30m

      Chair: Sandhya Choubey

      Speaker: Raymond R. Volkas (Univ Melbourne)
    • 15:00 15:30
      Solar and geoneutrinos 30m

      Chair: Sandhya Choubey

      Speaker: Livia Ludhova (Forschungszentrum Juelich and RWTH Aachen)
    • 15:30 16:00
      Break 30m
    • 16:00 16:30
      Light sterile neutrinos 30m

      Chair: Carlo Giunti

      Speaker: Stefano Gariazzo (INFN Torino)
    • 16:30 17:00
      Long-baseline neutrino oscillations review (including future) 30m

      Chair: Carlo Giunti

      Speaker: Patricia Vahle (College of William and Mary)
    • 17:00 17:30
      Coherent elastic neutrino-nucleus scattering 30m

      Chair: Carlo Giunti

      Speaker: Carla Bonifazi (ICAS - ICIFI - UNSAM / CONICET)
    • 13:30 14:15
      Hot topic Cosmology

      Chair: Gabriela Barenboim

      • 13:30
        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)
      • 13:45
        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)
      • 14:00
        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))
    • 13:30 14:15
      Hot topic Dark Matter: 1

      Chairs: Susana Cebrián (1), Riccardo Catena (2), Roberto Santorelli (3)

      • 13:30
        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)
      • 13:45
        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)
      • 14:00
        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)
    • 13:30 14:15
      Hot topic Neutrinos: 1

      Chairs: Silvia Capelli (1), Ninetta Saviano (2)

      • 13:30
        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)
      • 13:45
        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)
      • 13:55
        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)
      • 14:05
        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)
    • 14:30 15:00
      Double beta decay: theory review 30m

      Chair: Martin Hirsch

      Speaker: Frank Deppisch (University College London)
    • 15:00 15:30
      Double beta decay: experimental review 30m

      Chair: Martin Hirsch

      Speaker: Andrea Giuliani (IJCLab, U Paris-Saclay, Orsay)
    • 15:30 16:00
      Break 30m
    • 16:00 16:30
      Supernovae: neutrinos and gravitational waves 30m

      Chair: Junpei Shirai

      Speaker: Kei Kotake (Fukuoka University)
    • 16:30 17:00
      Reactor experiments review (including short-baseline) 30m

      Chair: Junpei Shirai

      Speaker: Cécile Jollet (Univ Bordeaux)
    • 17:00 17:30
      Review on underground laboratories 30m

      Chair: Junpei Shirai

      Speaker: Ezio Previtali (Univ Milano Bicocca & Gran Sasso Lab)
    • 14:30 15:00
      Inflation overview 30m

      Chair: Olga Mena

      Speaker: Richard Easther (Univ Auckland)
    • 15:00 15:30
      Cosmology overview 30m

      Chair: Olga Mena

      Speaker: Licia Verde (ICC, IEEC-Univ Barcelona - ICREA)
    • 15:30 16:00
      Break 30m
    • 16:00 16:30
      Dark matter and structure formation 30m

      Chair: Martina Gerbino

      Speaker: Matteo Viel (SISSA Trieste)
    • 16:30 17:00
      Multimessenger astronomy 30m

      Chair: Martina Gerbino

      Speaker: Andrii Neronov (APC Paris & Univ Geneve)
    • 17:10 18:00
      Discussion Panel Cosmology 1

      Chair: Savvas Nesseris

      • 17:10
        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)
      • 17:10
        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)
      • 17:40
        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)
      • 17:45
        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)
      • 17:45
        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))
      • 17:45
        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)
      • 17:45
        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)
    • 17:10 18:00
      Discussion Panel Dark Matter 1

      Chair: María Luisa Sarsa

      • 17:10
        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)
      • 17:25
        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)
      • 17:40
        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)
      • 17:45
        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)
      • 17:45
        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)
      • 17:45
        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)
      • 17:45
        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)
    • 17:10 18:00
      Discussion Panel Dark Matter 2

      Chair: Rebeca Gozzini

      • 17:10
        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)
    • 17:10 18:00
      Discussion Panel HE astrophys. & CRs/Multi-messenger astronomy 1

      Chair: Michela Negro

      • 17:10
        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)
    • 17:10 18:00
      Discussion Panel Neutrinos 1

      Chair: Masaki Ishitsuka

      • 17:10
        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))
    • 17:10 18:00
      Discussion Panel Neutrinos 2

      Chairs: Ninetta Saviano & Sovan Chakraborty

      • 17:10
        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:2102.02223

        Speaker: 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)
    • 17:10 18:00
      Discussion Panel Underground Laboratories 1

      Chairs: Aldo Ianni & Jeter Hall

      • 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.

        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)
    • 18:00 19:30
      Poster session 1

      Join the Gather.Town platform at:

      • 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)
      • 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) 205

        Speaker: 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.

        1. Research program towards observation of neutrino-nucleus coherent
          scattering., H. T. Wong et al., J. Conf. Ser. 39, 266 (2006).
        2. Coherency in neutrino-nucleus elastic scattering., S. Kerman et al., Phys. Rev. D93, 113006 (2016).
        3. 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)
      • 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)
    • 13:30 14:15
      Hot Topic Underground Laboratories

      Chairs: Aldo Ianni & Jeter Hall

      • 13:30
        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, Spain

        A. Tarifeño-Saldivia, F. Calviño, N. Mont, A. De Blas, R. García, G. Cortés
        Institute of Energy Technologies (INTE), Technical University of Catalonia (UPC), Barcelona, Spain

        L.M. Fraile, A. Domínguez Bugarín
        Grupo de Física Nuclear & IPARCOS, Universidad Complutense de Madrid (UCM), Madrid, Spain

        D. Bemmerer, M. Grieger
        Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany

        I. Dillmann
        TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada

        Neutrons 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))
      • 14:00
        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)
    • 13:30 14:15
      Hot topic Dark Matter: 2

      Chairs: Susana Cebrián (1), Riccardo Catena (2), Roberto Santorelli (3)

      • 13:30
        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)
      • 13:45
        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)
    • 13:30 14:15
      Hot topic HE astrophys. & CRs/Multi-messenger astronomy: 1

      Chairs: Ioana Maris (1), Miquel Ardid (2)

      • 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)
    • 13:30 14:15
      Hot topic Neutrinos: 2

      Chairs: Silvia Capelli (1), Ninetta Saviano (2)

      • 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)
    • 14:30 15:00
      Dark matter models (theory review) 30m

      Chair: Masaki Yamashita

      Speaker: Maxim Pospelov (Univ Minnesota)
    • 15:00 15:30
      Direct detection of dark matter (experimental review) 30m

      Chair: Masaki Yamashita

      Speaker: Marc Schumann (Univ Freiburg)
    • 15:30 16:00
      Break 30m
    • 16:00 16:30
      Axions as dark matter (theory & exp) 30m

      Chair: Jodi Cooley

      Speaker: Javier Redondo (Univ Zaragoza)
    • 16:30 17:00
      Light dark matter (theory & exp) 30m

      Chair: Jodi Cooley

      Speaker: Yonit Hochberg (Hebrew U, Jerusalem)
    • 17:10 18:00
      Discussion Panel Cosmology 2

      Chair: Maria Archidiacono

      • 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)
    • 17:10 18:00
      Discussion Panel Dark Matter 3

      Chair: María Martínez

      • 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)
      • 17:45
        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)
    • 17:10 18:00
      Discussion Panel Dark Matter 4

      Chairs: Theopisti Dafni & Igor G. Irastorza

      • 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)
    • 17:10 18:00
      Discussion Panel Dark Matter 5

      Chair: Avelino Vicente

      • 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)
    • 17:10 18:00
      Discussion Panel Gravitational Waves 1

      Chair: Sukanta Bose

      • 17:10
        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)
    • 17:10 18:40
      Discussion Panel Neutrinos 3

      Chair: Silvia Capelli

      • 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.

        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 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)
    • 17:10 18:00
      Discussion Panel Neutrinos 4

      Chair: Georgia Karagiorgi

      • 17:10
        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)
    • 20:00 21:00
      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

        Speaker: David G. Cerdeño (IFT (UAM-CSIC))
    • 14:30 15:00
      GW astrophysics (future discoveries) 30m

      Chair: Claudia Lazzaro

      Speaker: Paul Lasky (Monash Univ)
    • 15:00 15:30
      Gravitational-wave and multi-messenger observations: results and prospects 30m

      Chair: Claudia Lazzaro

      Speaker: Marica Branchesi (GSSI and Gran Sasso Lab)
    • 15:30 16:00
      Break 30m
    • 16:00 16:30
      Gamma-ray astronomy from space 30m

      Chair: Carlos Delgado

      Speaker: Regina Caputo (NASA Goddard Space Flight Center)
    • 16:30 17:00
      Gamma-ray astronomy from the ground 30m

      Chair: Carlos Delgado

      Speaker: Gabrijela Zaharijaš (Nova Gorica U)
    • 17:10 18:00
      Discussion Panel Cosmology 3

      Chair: Mar Bastero-Gil

      • 17:10
        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)
    • 17:10 18:00
      Discussion Panel Dark Matter 6

      Chair: David G. Cerdeño

      • 17:10
        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
        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.

        1. 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)
        2. 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)
        3. 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)
        4. 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)
        5. 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