Baikal-GVD is a cubic-kilometer scale deep-underwater neutrino detector being constructed in Lake Baikal. Since April 2020 the detector includes seven 8-string clusters carrying in total 2016 optical modules located at depths from 750 m to 1275 m. The progress in the construction and operation of the Baikal-GVD is reported. We review the scientific case for Baikal-GVD, the construction plan,...
Observations of high-energy astrophysical neutrinos in IceCube have opened the door to multi-messenger astronomy, by way of which questions in particle physics could be explored collaboratively between IceCube and optical experiments such as Fermi-LAT. However, the origin of these astrophysical neutrinos is still largely unknown. Among the tensions that still need to be resolved, for example,...
IceCube-Gen2 is a future large-scale extension to the IceCube Neutrino Observatory, a kilometer-scale neutrino detector at the geographic South Pole. The IceCube data acquisition system (DAQ) architecture, while running stably with over 99% uptime, will be re-optimized for IceCube-Gen2 to solve design challenges with power consumption, communications bandwidth, and cable specifications, while...
An accurate atmospheric neutrino flux is crucial for a multitude of physics studies with modern neutrino telescopes; as a signal for neutrino oscillation measurements, and as a background for searches of astrophysical neutrino sources. We seek to advance in the low-energy neutrino flux calculations (up to a few GeV) using the MCEq (Matrix Cascade Equations) code that numerically solves the...
X-ray binaries (XRBs) are binary system with an accreting compact object. They have long been suggested to be possible galactic cosmic ray accelerators. In such models, the protons accelerated by the accretion process at the compact object could carry out $pp$ or $p\gamma$ interactions in the accretion disk, in the atmosphere of the companion star, or in the stellar wind. High energy neutrinos...
The Baikal-GVD neutrino telescope is currently a multi-cluster infrastructure composed by 7 separately operating clusters of more than 2000 photosensitive modules in lake Baikal. Single cluster comprises 8 strings of 288 optical modules by means of 36 OM on each string divided into three groups (sections) of 12-channel control modules with ADCs. Two independent systems of time synchronization...
An anomalous flux of neutrinos produced in hypothetical annihilations or decays of dark matter inside a source would produce a signal observable with neutrino telescopes. As suggested by observations, a conspicuous amount of dark matter is believed to accumulate in the Centre of our Galaxy, which is in neat visibility for the Mediterranean underwater telescopes ANTARES and KM3NeT. Searches...
Multi-messenger detections of astrophysical events improve our understanding of the underlying sources. In addition to probing different physics, such detections can provide improved localization in low latency, guiding astronomers who perform follow-up observations. We will present the real-time and offline searches for high-energy neutrinos associated with gravitational-wave events via...
The KM3NeT Collaboration has already produced electronics to produce more than one thousand Digital Optical Modules, which have started to be deployed at the bottom of the Mediterranean Sea. An upgrade of the electronics is currently underway, expecting to have a revision of it by mid-2021 Here we describe the main improvements added to the DOM electronics, including the new high reliability...
KM3NeT is a deep-sea infrastructure composed of two neutrino telescopes being deployed in the Mediterranean Sea : ARCA, near Sicily in Italy, designed for neutrino astronomy and ORCA, near Toulon in France, designed for the study of atmospheric neutrino oscillations. These two telescopes are 3D arrays of optical modules used to detect the Cherenkov radiation, which is a signature of charged...
The gSeaGen framework has been upgraded to simulate events detectable in neutrino telescopes induced by neutrino or cosmic ray interactions. The new version is well-suited to generate neutrino interactions at energies from a few MeV to EeV, profiting from the latest GENIE extensions to lower and higher energies. In addition, a brand new functionally to propagate leptons from CORSIKA air...
The high-energy neutrino events of the IceCube telescope, which trigger
neutrino alerts in one of two probability ranks of astrophysical origin,
“gold " and "bronze", have been followed up with Baikal-GVD in a fast
quasi-online mode since September 2020. Search for correlations between
alerts and events reconstructed in two modes, track and cascade, for the
time windows \pm 1 hour and \pm 12...
The simulation of the neutrino interaction vertex is a crucial step for the simulation chain of a neutrino experiment. The different processes taking part in the neutrino scattering at a nucleus require several approximations in order to make the simulation possible and to realize reasonable computation times. This can be realised in different ways, e.g. by parametrised models for the...
Bouke Jung$^1$, Maarten de Jong$^2$, Paolo Fermani$^3$
on behalf of the KM3NeT collaboration
$^1$) University of Amsterdam, Nikhef
bjung@nikhef.nl
$^2$) Leiden University, Nikhef
mjg@nikhef.nl
$^3$) Sapienza Università di Roma
paolo.fermani@roma1.infn.it
Present and foreseen neutrino observatories, such as IceCube, P-ONE, GVD, Antares and KM3NeT have to operate in challenging environments,...
Neutrino telescopes, such as IceCube, can be used to conduct indirect dark matter searches. A common assumption is that dark matter consists of Weakly Interacting Massive Particles (WIMPs), which are expected to produce standard model particles when they annihilate or decay. IceCube could then detect the neutrinos generated by these standard model particles. Since the Milky Way is expected to...
The KM3NeT project aims to build a neutrino telescope in the depth of the Mediterranean Sea. The detector consists of a Kilometer-cube grid of Optical Modules, photosensors encapsulated into transparent pressure resistant glass spheres. A crucial component is the acoustic positioning system, which provides the position of photodetectors and structures in the deep sea with an accuracy of about...
With neutrino astronomy on the rise, calibration aspects of large-volume detectors are becoming one of the key targets to boost detector performance. In the scope of the IceCube Upgrade planned for the South Pole season of 2022/23, we developed a novel isotropic, self-monitoring, precision calibration light source aimed for use in large-volume detectors in order to boost understanding of the...
Baikal-GVD is a gigaton-scale neutrino observatory under construction in Lake Baikal. It currently produces about 100GB of data every day. For their automatic processing, the Baikal Analysis and Reconstruction software (BARS) was developed. At the moment, it includes such stages as a hit extraction from PMT waveforms, assembling events from raw data, assigning timestamps to events, determining...
The current activity of the Baikal-GVD neutrino experiment in the multi-messenger program on discovering the astrophysical sources of high energy fluxes of cosmic particles will be presented, with emphasis on results of the follow up of high energy neutrino alerts.
The first stage of the construction of the deep underwater neutrino telescope Baikal-GVD is planned to be completed in 2024. The second stage of the detector deployment is planned to be carried out using a data acquisition system based on fiber optic technologies, which will allow for increased data throughput and more flexible trigger conditions. A dedicated test facility has been built and...
The existence of dark matter (DM) has been well-established by repeated observations probing many length scales. Although DM is expected to comprise the majority of the current matter content of the Universe, its nature remains unknown. Weakly interacting massive particles (WIMPs) are a class of DM that arise naturally from Standard Model (SM) extensions. Generically WIMPs have a non-zero...
In 2017, a high-energy muon neutrino detected by IceCube was found positionally coincident with the direction of a known blazar, TXS 0506+056, in a state of enhanced $\gamma$-ray emission. Soon after, IceCube reported a compelling evidence for an earlier neutrino flare from the same direction found in the archival data, this time not accompanied by any observed electromagnetic activity. The...
Waveform unfolding, in which photomultiplier tube signals are expressed as a linear combination of single-photoelectron waveforms, is a useful processing method both for analysis and for data compression in the IceCube Neutrino Observatory. This processing is currently only possible with a cluster of computers on the surface, but improvements in embedded technology allow moving this analysis...
The KM3NeT Collaboration is currently deploying the first Detection Units of a neutrino observatory in the Mediterranean Sea, which, once completed, will be equipped with tens of thousand of so-called Digital Optical Modules. In addition to the Detection Units KM3NeT has designed an independent Calibration Unit, housing a set of calibration instruments, including e.g. an acoustic beacon and a...
The ANTARES neutrino telescope is operating in the Mediterranean Sea in its full configuration since 2008. On their journey to the Earth, cosmic rays (CRs) can be absorbed by celestial objects, like the Sun, leading to a deficit in secondary muons produced by CR interactions from the solid angle region covered by the Sun, the so-called Sun "shadow" effect. This phenomenon can be used to...
The IceCube neutrino observatory consists of 5160 photomultiplier-tubes spread among 86 vertical strings making a total
detector volume of more than a cubic kilometer. It detects neutrinos via Cherenkov light of
charged relativistic particles from neutrino interactions with the detector volume. In this
analysis we search for secluded dark matter which annihilates into metastable mediator...
The main purpose of the Baikal-GVD Data Quality Monitoring (DQM) system is to verify the detector status and collected data in both on- and off-line modes. Besides the quality estimation of the obtained data and providing the charge calibration using recorded signals the system efficiently performs validation of the trigger thresholds, as well as the monitoring of the environmental noise...
The KM3NeT Collaboration has already produced more than one thousand acquisition boards, used for building two deep-sea neutrino detectors at the bottom of the Mediterranean Sea, with the intention of instrumenting a volume of several cubic kilometers. The acquisition modules, the so-called Digital Optical Modules, house the PMTs and the acquisition and control electronics of the module, the...
We present the results of a one year monitoring of absorption and scattering lengths of light with wave length 375÷532nm within the effective volume of the
Baikal-GVD deep underwater neutrino telescope. The measurements were
performed using a dedicated device, BAIKAL-5D, which was installed
during the 2020 winter expedition at a depth 1250 m. The device has a shaded point-like isotropic...
Neutrinos have been proved to be unique messengers in the understanding of fundamental physics processes, particularly in the astrophysics field. Also, they are thought to be able to provide hints of physics beyond the Standard Model, like Dark Matter models, among which those based on Weakly Interacting Massive Particles (WIMPs) physics. This kind of Dark Matter can scatter off Standard...
Baikal-GVD is a gigaton volume neutrino telescope currently under construction in Lake Baikal. GVD's detection, calibration and control units are submerged between the depths of 730 and 1275 meters and are equipped with sensors allowing for monitoring the state of individual components. Spatial configuration of the entire detector is obtained using an acoustic positioning system consisting of...
Cosmic rays interact with nucleons in the solar atmosphere to create pions, kaons, and other particles which decay to produce a flux of high-energy neutrinos. Although this flux is predicted in the literature, it has yet to be observed experimentally. This flux is an irreducible background for current solar WIMP searches. The detection of these neutrinos would improve the sensitivity floor for...
Starburst galaxies (SBGs) and more in general starforming galaxies represent a class of galaxies with a high star formation rate (up to 100 Mo/year). Despite their low luminosity, they can be considered as guaranteed “factories” of high energy neutrinos, being “reservoirs” of accelerated cosmic rays and hosting a high density target gas in the central region. In this contribution we present a...
The standard model with three flavor neutrino oscillations is supported by the majority of neutrino oscillation data. However, a few experiments have observed anomalies, which are difficult to accommodate within the three flavour framework. One possible explanation of some anomalies is to postulate the existence of light sterile neutrinos.
Neutrino telescopes such as ANTARES and KM3NeT are...
For testing and optimizing key elements of the KM3NeT data acquisition system, a test-bench has been set up at the INFN Sezione di Bologna. In this setup, a full detection unit is simulated, to test the optical network, time synchronisation, and on-shore computing resources. A fundamental tool in the test-setup is a dedicated electronic board: “the OctoPAES”.
Based on an ALTERA Max10 CPLD,...
The IceCube Neutrino Observatory, located under 1.4 km of Antarctic ice,
instruments a cubic kilometer of ice with 5,160 optical modules that detect
Cherenkov radiation originating from neutrino interactions. The more
densely instrumented center, DeepCore, aims to detect atmospheric neutrinos
at 10-GeV scales to improve important measurements of fundamental neutrino
properties such as the...
Gamma-Ray Bursts (GRBs) are considered very interesting astrophysical sources to be studied in the context of the neutrino astronomy. Indeed, their jet composition continues to be an open issue. Within the framework of the fireball model, mesons can be produced during photo-hadronic interactions occurring in the internal shocks between shells emitted by the central engine. From their decays,...
The
IceCube Neutrino Observatory is designed to observe neutrinos interacting deep within the South Pole ice. It consists of 5,160 digital optical modules, which are arrayed over a cubic kilometer from 1,450 m to 2,450 m depth. At the lower center of the array is the DeepCore subdetector. It has a denser configuration which lowers the observable energy threshold to about 10 GeV and creates...
The KM3NeT Collaboration is building a deep-sea neutrino observatory in the Mediterranean Sea equipped with thousands of glass spheres, hosting the so-called Digital Optical Modules, with an instrumented volume of several cubic kilometers. Reliability of the components used in the construction of the detectors is of extreme importance as the deployed Detection Units, each one composed of 18...
Existing anomalies in experimental results, for neutrino oscillation experiments, may require a fourth, “sterile” neutrino with non-interacting flavor states. Recent sterile neutrino results from the IceCube South Pole Neutrino Observatory, a Cherenkov neutrino experiment using a cubic kilometer of instrumented ice, are presented. Multiple analyses are discussed, including one enabled by a...
The Baikal-GVD is a large scale neutrino telescope being constructed in Lake Baikal. The majority of signal detected by the telescope are noise hits, caused primarily by the luminescence of the Baikal water. Separating noise hits from the hits produced by Cherenkov light emitted from the muon track is a challenging part of the muon event reconstruction. We present an algorithm that utilizes a...
The discovery of a diffuse flux of astrophysical neutrinos by IceCube has opened up new possibilities for the search of cosmic-ray sources. The sources that accelerate cosmic rays to extreme energies are most-likely also high-energy neutrino emitters. To find such sources one can look for correlations in arrival directions between astrophysical neutrinos and ultra-high-energy cosmic rays...
Several anomalies in reactor and accelerator neutrino experiments motivate the search for sterile neutrinos at mass splittings in the eV-scale. We present an analysis that probes the elements $U_{\mu4}$ and $U_{\tau4}$ of the extended (3+1) neutrino mixing matrix using an 8 year data sample from IceCube’s DeepCore sub-array containing atmospheric neutrinos between 5 and 300 GeV. The analysis...
The large scalar neutrino detectors (JUNO, HyperK), need the 20 inch area PMTs as the photo-detection device for their large photocathode coverage and less electronic channels. In 2009, the researchers at IHEP have conceived a new concept of large area PMTs, of which the small MCP units replace the bulky Dynode chain. After several years R&D, the 20 inch MCP-PMT was successfully produced. This...
Novel optical sensor design decouples the photo-sensitive area from the PMT cathode area. Light guides can be shaped in a more favourable geometry for the target detector.
Twelve wavelength shifting optical modules (WOMs) will be deployed in the IceCube Upgrade.
The photo-sensitive area is a long cylinder coated with wavelength shifting paint which exploits the UV part of the Cherenkov...
Muon track reconstruction methods developed for Baikal-GVD detector
and their performance are discussed in this talk. This includes
methods for the rejection of noise due to water chemilumenescence and
track parameter reconstruction based on chi^2 minimisation. The
performance of the algorithms is assessed using realistic Monte Carlo
(MC) simulations of the detector. Benchmark results obtained...
KM3NeT is a multi-purpose cubic-kilometer neutrino observatory in construction in the Mediterranean Sea. It consists of ORCA and ARCA (for Oscillation and Astroparticle Research with Cosmics in the Abyss, respectively), currently both with a few detection lines in operation. Although having different primary goals, both detectors can be used for neutrino astronomy over a wide energy range,...
Strange quark matter (SQM) is a hypothetical type of matter composed of almost equal quantities of up, down and strange quarks. Massive SQM particles are called nuclearites. Nuclearites with masses greater than $10^{13}$ GeV and velocities of about 250 km/s (typical galactic velocities) could reach the Earth and interact with atoms and molecules of sea water within the sensitive volume of the...
A new long optical module (LOM) is under development for IceCube-Gen2, the proposed expansion to the IceCube neutrino observatory at the South Pole. The module is housed in an elongated borosilicate-glass pressure vessel, the size of which is constrained by the borehole diameter, which impacts drilling economy. The designs under consideration use either 16 or 18 4-inch PMTs, conditional on...
ANTARES is currently the largest undersea neutrino telescope, located in the Mediterranean Sea and taking data in its full configuration since 2008. It consists of a 3D array of photosensors, instrumenting about 10Mt of seawater to detect Cherenkov light induced by secondary particles from neutrino interactions. The event reconstruction and background discrimination is challenging and...
The ANTARES neutrino telescope has been operating in the Mediterranean sea since 2008 in its full configuration, with the main purpose of searching for high-energy cosmic neutrinos. During the last years, multi-messenger astronomy has become one of the most exciting topics in astroparticles, and a promising strategy to identify astrophysical sources of neutrinos. The ANTARES Collaboration is...
ANTARES is a Cherenkov underwater neutrino telescope operating in the Mediterranean Sea since 2008 in its full configuration. Even though optimised for the search of cosmic neutrinos, this telescope is also sensitive to nuclearites of strange matter.
We discuss here the possible detection of non-relativistic down-going nuclearites with the ANTARES telescope and present the first results of an...
KM3NeT is constructing two large neutrino detectors in the Mediterranean Sea: KM3NeT/ARCA, located near Sicily and aiming at neutrino astronomy, and KM3NeT/ORCA, located near Toulon and designed for neutrino oscillation studies. The two detectors, together, will have hundreds of Detection Units (DUs) with 18 Digital Optical Modules (DOMs) maintained vertical by buoyancy, forming a large 3D...
The present study is an updated search for magnetic monopoles using data taken with the ANTARES neutrino telescope over a period of 10 years (January 2008 to December 2017). In accordance with some grand unification theories, magnetic monopoles could have been created during the phase of symmetry breaking in the early Universe, and accelerated by galactic magnetic fields. As a consequence of...
At the last VLVnT-conference in the talk “NEVOD as a test facility for future neutrino telescopes” presented by A.A. Petrukhin the methods for testing of optical modules inside the volume of the Cherenkov water detector NEVOD have been discussed. It was assumed that in 2020 the new optical module mDOM of the IceCube-Upgrade will be calibrated in this way. However, the covid-19 pandemic did not...
Magnetic monopoles are hypothetical particles carrying magnetic charge. They are predicted to exist in most extensions of the Standard Model of particle physics. A wide range of masses is allowed for magnetic monopoles, leading to a broad speed range for a hypothetical flux of these relics of the Big Bang. A magnetic monopole passing through IceCube would produce light through several...
The IceCube-Gen2 Neutrino Observatory will feature an in-ice optical array, a larger in-ice radio detector array, and a surface cosmic ray air shower array.
The surface array will consist of stations based on the experience from the planned IceTop enhancement, each station having 4 pairs of scintillator panels, 3 radio antennas and a central hub hosting electronics for data readout and time...
Data collected by the Baikal Gigaton Volume Detector (Baikal GVD) needs to be processed in real time at a data centre located in Dubna, Moscow Oblast, approx. 4,300 km away. An infrastructure facilitating data transfer and storage was designed and implemented. In this paper, we discuss the details of the implementation and our approach to ensuring fault tolerance and 24/7 access to the data.
In this talk I present the results from our global fit to neutrino oscillation data. Neutrino oscillation experiments have reached a very good level in precision. Due to correlations among parameters a global fit combining many different datasets can give more precise results than a single experiment on its own. I will present the results of the latest global fit performed by our group and...
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...
Detection of high energy astrophysical neutrinos is the main aim of Baikal-GVD (Gigaton Volume
Detector) neutrino experiment located in the southern part of Lake Baikal. It is a three dimensional grid of optical modules (OMs), which are attached to the vertical cables, called strings. The whole detector is sub-arranged into functionally independent units, referred to as clusters.
Highly...
The IceCube Neutrino Observatory is a cubic kilometer-sized detector designed to detect neutrinos of astrophysical origin. We discuss a new method using a boosted decision tree to classify and reduce the cosmic ray muon rates from ~billion per year to ~1 per year, the same BDT is also used to select for starting track events (~900 per year). The classification and removal of incoming muons is...
In the upcoming decades, the KM3NeT detectors will produce valuable data that can be used in various scientific contexts from astro- and particle physics to environmental and Earth and Sea science. Based on the Open Science policy established by the KM3NeT Collaboration, several efforts to offer science-ready data, foster common analysis approaches and publish open source software are...
The IceCube neutrino observatory, along with its DeepCore in-fill array, detects a large amount of atmospheric and astrophysical neutrinos across a wide range of energies from GeV to PeV. DeepCore is sensitive in measuring neutrino oscillation parameters using events in GeV-TeV range. This talk will present an update of muon neutrino disappearance analysis using 8 years of DeepCore data, using...
Recently, evidence for an association between high energy neutrinos detected by
IceCube and radio-selected blazars has been found by Plavin et al. (2020, 2021). This result was achieved using an all sky complete sample of 3411 blazars selected on their parsec-scale flux density at 8 GHz higher than 150 mJy. We perform an analysis using the same sample of radio-selected blazars and search for a...
The DeepCore sub-array within the IceCube Neutrino Observatory is a densely instrumented region of Antarctic ice designed to observe atmospheric neutrino interactions above 5 GeV via Cherenkov radiation. An essential aspect of any neutrino oscillation analysis is the ability to accurately identify the flavor of neutrino events in the detector. This task is particularly difficult at low...
The determination of neutrino mass ordering (NMO) is one of the prime goals of several neutrino experiments. KM3NeT/ORCA and JUNO are two next-generation neutrino oscillation experiments both aiming at addressing this question. ORCA can determine the NMO by probing Earth matter effects on the oscillation of atmospheric neutrinos in the GeV energy range. JUNO, on the other hand, is sensitive to...
The IceCube Neutrino Observatory has detected high-energy astrophysical
neutrinos in the TeV-PeV range. These neutrinos have an isotropic
distribution on the sky, and therefore likely originate from extragalactic
sources. Active Galactic Nuclei (AGN) form a class of astronomical objects
which are promising neutrino source candidates given their high
electromagnetic luminosity and potential...
The Control Unit of the KM3NeT Data Acquisition is the software suite that is responsible for operating all the components of the KM3NeT telescopes in a coordinated and scientifically proficient way. It controls a wide span of parameters and procedures, from the power supplies, to the operating voltages of more than 64000 photomultipliers in each detector block, to the setup of the various...
Muons and neutrinos created by cosmic rays interacting in the atmosphere create a significant background for IceCube astrophysical neutrinos in the southern sky. However, looking for neutrino events that start in the detector can reduce both the atmospheric muon and atmospheric neutrino background while retaining the astrophysical neutrino signal. The method presented here results in a higher...
The detection of astrophysical $\nu_\tau$ is an important verification of the observed flux of high-energy neutrinos. A flavour ratio of $\nu_{e} : \nu_\mu : \nu_\tau \approx 1 : 1 : 1$ is predicted for astrophysical neutrinos measured at Earth due to neutrino oscillations. On top of this, the $\nu_\tau$ offers a unique channel for neutrino astronomy due to absence of an atmospheric $\nu_\tau$...
In the search for astrophysical neutrinos, neutrino telescopes instrument large volumes of clear natural water. Photomultiplier tubes placed along mooring lines detect the Cherenkov light of secondary particles produced in neutrino interactions, and allow us to search for possible neutrino sources in the sky. The P-ONE experiment proposes a new neutrino telescope off the shore of British...
The existence of neutrino masses and tensions between measurements of neutrino mixing parameters indicates there is new physics yet to be discovered. A viable explanation for these discrepancies are non-standard interactions (NSI)— subdominant neutrino-quark interactions not described by the Standard Model (SM). A portion of neutrinos detected by IceCube travel through distances of Earth’s...
KM3NeT, a neutrino telescope currently under construction in the Mediterranean Sea, consists of a network of large-volume Cherenkov detectors. Its two different sites, ORCA and ARCA, are optimised for few GeV and TeV-PeV neutrino energies, respectively. This allows for studying a wide range of physics topics spanning from the determination of the neutrino mass hierarchy to the detection of...
In order to accurately reconstruct track and cascade events in a neutrino telescope, it is necessary to have information about the optical properties of the medium. The main purpose of the laser event analysis is to evaluate the light absorption length and the light scattering length in the deep Baikal water. Currently, the Baikal-GVD detector is equipped with 5 lasers with a wavelength of 532...
Non-standard interactions (NSIs) in the propagation of neutrinos in matter can lead to significant deviations in neutrino oscillations expected within the standard neutrino oscillation framework. These additional interactions would result into an anomalous flux of neutrinos discernible at neutrino telescopes. The ANTARES detector and its next-generation successor, KM3NeT, located in the...
Baikal-GVD is a next generation, kilometer-scale neutrino telescope currently under construction in Lake Baikal. GVD is formed by multi-megaton subarrays (clusters) and is designed for the detection of astrophysical neutrino fluxes at energies from a few TeV up to 100 PeV. The design of Baikal-GVD allows one to search for astrophysical neutrinos with flux values measured by IceCube already at...
The IceCube Neutrino Observatory investigates high-energy astrophysical phenomena by studying the corresponding high-energy neutrino signal. Its successful discovery of a diffuse flux of astrophysical neutrinos with energies up to the PeV scale in 2013 has triggered a vast effort to identify this signal's sources, which recently resulted in an improved analysis method. Here, we present a new...
The IceCube Neutrino Observatory instruments about 1 km^3 of deep, glacial ice at the geographic South Pole using 5160 photomultipliers to detect Cherenkov light from relativistic, charged particles. Most IceCube science goals rely on precise understanding and modelling of the optical properties of the instrumented ice. A peculiar light propagation effect observed by IceCube is an anisotropic...
The phenomenon of Neutrino Oscillation has been very well confirmed by a plethora of data; we are now entering a precision era in which the mixing angles and mass differences are going to be measured with unprecedented precision by ongoing and planned experiments. However, the new measurements could reveal that the standard three flavor scenario is not enough for a complete description of...
The Baikal-GVD detector currently consists of 2016 optical modules arranged on 56 vertical strings in a water volume of 0.35 km$^3$. The data from the partially complete array have been analyzed using a $\chi^2$-based track reconstruction algorithm. After a zenith angle cut and other background suppression cuts, a sample of upgoing neutrino candidate events is obtained. The analysis is...
The large-scale deep underwater Cherenkov neutrino telescopes like Baikal-GVD, ANTARES or KM3NeT, require calibration and testing methods of their optical modules. These methods usually include laser-based systems which allow to check the telescope responses to the light and for real-time monitoring of the optical parameters of water such as absorption and scattering lengths, which show...
High-energy neutrinos with energies above a few $10^{16}~$eV can be measured efficiently with in-ice radio detectors which is explored successfully in the ARIANNA test-bed detector, an array of shallow radio detector stations. Here, we demonstrate the neutrino pointing capabilities of a shallow radio station. Using the residual hole from the South Pole Ice Core Project, radio pulses were...
Numerous astrophysical and cosmological experiments have observed the effects of dark matter, however, its properties have yet to be discovered. Simultaneously, the nature of high-energy astrophysical neutrinos detected by IceCube remains unresolved. If dark matter and neutrinos are coupled to each other, they may exhibit a non-zero elastic scattering cross section. Such an interaction between...
The next generation of neutrino telescopes, including Baikal-GVD, KM3NeT, P-ONE, TAMBO, and IceCube-Gen2, will be able to determine the flavor of high-energy astrophysical neutrinos with 10% uncertainties. With the aid of future neutrino oscillation experiments --- in particular JUNO, DUNE, and Hyper-Kamiokande --- the regions of flavor composition at Earth that are allowed by neutrino...
Long-baseline neutrino experiments using very large volume neutrino telescopes
as far detectors can collect sizeable neutrino samples - $\mathcal{O}(10^3) \nu_e/year$ - even with moderate beam intensities - $\mathcal{O}(100) kW$. The presentation will show that at these intensities it is possible to instrument the beam with charged particle silicon pixel trackers to reconstruct precisely the...
The KM3NeT Collaboration is constructing two deep-sea Cherenkov detectors in the Mediterranean Sea. The ARCA detector aims at TeV-PeV neutrino astronomy, while the ORCA detector is optimized for atmospheric neutrino oscillation studies at energies of a few GeV. In this contribution, an analysis of the data collected with the first deployed detection units of the ARCA detector is presented. A...
The Glashow resonance describes the resonant production of a W− boson during
the interaction of an electron antineutrino with an electron.
The cross-section of this process peaks at an antineutrino energy of 6.3 petaelectronvolts (PeV) in the rest frame of the electron.
In this talk, I will report on the observation by the IceCube Neutrino Observatory of a neutrino-induced particle shower with...
The KM3NeT research infrastructure in the Mediterranean is a multi-purpose cubic-kilometer neutrino observatory consisting of two detectors optimized to study cosmic and atmospheric neutrinos between GeV to PeV energies. Additionally, KM3NeT multi-photomultiplier optical modules allow the detection of nearby MeV interaction products by selecting nanosecond coincidences within the...
Baikal-GVD is a neutrino telescope situated in the deepest freshwater lake in the world – Lake Baikal. It is a three-dimensional array of photo-multiplier tubes, that are arranged in independently working units called clusters. The main purpose of this telescope is to detect neutrinos via detecting the Cherenkov radiation of the secondary charged particles that are created in the interactions...
The ANTARES neutrino telescope, located in the Mediterranean Sea, is the longest-operated under-sea neutrino detector, having collected data for more than 14 years and since 2008 in its full configuration. These data have been used to search for a diffuse flux of cosmic neutrinos, upgrading previously published results both in terms of livetime and in search method. In particular, a new event...
The KM3NeT Collaboration has successfully deployed the first detection units of the next generation undersea neutrino telescopes in the Mediterranean Sea at the two sites in Italy and in France. The data sample collected between December 2016 and January 2020 has been used to measure the atmospheric muon rate at two different depths under the sea level: 3.5 km with KM3NeT/ARCA and 2.5 km with...
While large neutrino telescopes have so far mainly focused on the detection of TeV-PeV astrophysical neutrinos, several efforts are ongoing to extend the sensitivity down to the GeV level for transient sources. Only a handful of searches have been carried out at the moment leaving the signature of astrophysical transients poorly known in this energy range.
In this contribution, we discuss the...
The KM3NeT infrastructure comprises a network of underwater neutrino telescopes in the Mediterranean Sea. Secondary particles, produced when neutrinos interact, emit Cherenkov photons which are measured by the KM3NeT detectors.
In order to precisely reconstruct muon tracks and showers, it is necessary to know the position of the photomultipliers with an accuracy of about 10 cm.
For this...
ORCA, Oscillation Research with Cosmics in the Abyss, is the low energy KM3NeT neutrino underwater detector, located in the French Mediterranean sea. It comprises a dense array of optical modules designed to detect the emitted Cherenkov light emitted from charged particles resulting from neutrino interactions in the vicinity of the detector. Its main physics goal is the determination of the...
KM3NeT, a new generation of neutrino telescope, is currently being deployed in the Mediterranean Sea. While its two sites, ORCA and ARCA, were respectively designed for the determination of neutrino mass hierarchy and high-energy neutrino astronomy, this contribution presents a study of the detection potential of KM3NeT in the MeV-GeV energy range. At these low energies, the data rate is...
Our knowledge about the Earth's interior is mainly based on seismic measurements, cosmochemical and petrological constraints, and theories of Earth formation. Whereas the matter density profile is determined with a high precision, the chemical composition of the deep Earth can only be estimated indirectly. In particular the amount and nature of light elements in the Core remain controversial....
The identification of cosmic objects emitting high energy neutrinos could provide new insights about the Universe and its active sources. The existence of these cosmic neutrinos has been proven by the IceCube collaboration, but the big question of which sources these neutrinos originate from, remains unanswered. The KM3NeT detector for Astroparticle Research with Cosmics in the Abyss (ARCA),...
