Showing papers on "Neutrino detector published in 2023"
TL;DR: In this article , the authors leverage the wide energy range of the IceCube Neutrino Observatory to search for neutrinos from GRB 221009A, finding no significant deviation from background expectation across event samples ranging from MeV to PeV energies, placing stringent upper limits on neutrino emission from this source.
Abstract: Gamma-ray bursts (GRBs) have long been considered a possible source of high-energy neutrinos. While no correlations have yet been detected between high-energy neutrinos and GRBs, the recent observation of GRB 221009A—the brightest GRB observed by Fermi-GBM to date and the first one to be observed above an energy of 10 TeV—provides a unique opportunity to test for hadronic emission. In this paper, we leverage the wide energy range of the IceCube Neutrino Observatory to search for neutrinos from GRB 221009A. We find no significant deviation from background expectation across event samples ranging from MeV to PeV energies, placing stringent upper limits on the neutrino emission from this source.
6 citations
TL;DR: In this paper , the neutrino flux from two LHAASO sources (J2226+6057 and J1908+0621) is estimated using the spectral power law index.
Abstract: Recently, Large High Altitude Air Shower Observatory (LHAASO) has detected several Galactic point sources of ultra high energy (UHE; $E_{\gamma}>100$ TeV) gamma-rays. These gamma-rays are possibly created in leptonic or hadronic interactions of cosmic rays (CRs) of PeV energies. In the hadronic channel ($p-p$ interaction), the gamma-rays are accompanied by neutrinos. The detection of neutrinos is therefore crucial in understanding CR acceleration in such objects. To estimate the neutrino flux, we adopt the two LHAASO sources (J2226+6057, J1908+0621) found to be spatially associated with the Supernova remnants (SNR G106.3+2.7, SNR G40.5-0.5). For these two sources, the detected TeV-PeV gamma-ray spectra are found to be unusually hard (with spectral index $\sim$ 1.8). We develop a model of gamma-ray and neutrino emission based on the above two prototypes. The neutrino fluxes from these two sources are found to be below the IceCube sensitivity, but are detectable in upcoming IceCube-Gen2 and KM3NeT experiments. We further estimate the neutrino fluxes from similar other 10 LHAASO PeVatron sources and most of them are found to be detectable in IceCube-Gen2 and KM3NeT. Finally, we explore our model parameters, in particular the spectral power law index and estimate the future potential of the neutrino detectors to probe CR acceleration in such Galactic sources.
3 citations
TL;DR: In this paper , it was shown that the absence of these decay daughters yields the strongest constraints to date for sterile neutrino masses inside a $1-100$ keV window.
Abstract: We scrutinize the hypothesis that gauge singlet fermions -- sterile neutrinos -- interact with Standard Model particles through the transition magnetic moment portal. These interactions lead to the production of sterile neutrinos in supernovae followed by their decay into photons and active neutrinos which can be detected at $\gamma$-ray telescopes and neutrino detectors, respectively. We find that the non-observation of active neutrinos and photons from sterile-neutrino decay associated to SN1987A yields the strongest constraints to date on magnetic-moment-coupled sterile neutrinos if their masses are inside a $0.1-100$ MeV window. Assuming a near-future galactic supernova explosion, we estimate the sensitivity of several present and near-future experiments, including Fermi-LAT, e-ASTROGAM, DUNE, and Hyper-Kamiokande, to magnetic-moment-coupled sterile neutrinos. We also study the diffuse photon and neutrino fluxes produced in the decay of magnetic-moment coupled sterile neutrinos produced in all past supernova explosions and find that the absence of these decay daughters yields the strongest constraints to date for sterile neutrino masses inside a $1-100$ keV window.
2 citations
22 Jan 2023
TL;DR: The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator experiment under construction in South China, at Kaiping, Jiangmen, Guandong province as discussed by the authors .
Abstract: The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator experiment under construction in South China, at Kaiping, Jiangmen, Guandong province. Its primary physics goals are the determination of the neutrino mass ordering and the precise determination of the neutrino oscillation parameters by means of the accurate measurement of the oscillated spectrum of antineutrinos emitted by two reactor complexes, Taishan and Yangjiang, located at 53 km distance from the experiment. Given its dimensions and anticipated performance, JUNO has a very rich physics program which includes the study of neutrinos from the Sun, the Earth, the Galaxy, and eventually from Supernovae, and will give important contributions to the study of new physics processes. The JUNO collaboration plans to finish the detector construction by the end of 2023. In this paper I review the detector progress and the updated sensitivities on the main physics channels.
2 citations
08 May 2023
TL;DR: In this article , the first strong evidence of a standalone neutrino source and a highly probable coincidence of neutrinos alert with gamma-ray bursts was presented. But the results of this paper are based on the same model as those of the recent results of the Deep Sea and Lake Neutrino Telescope (DSN).
Abstract: Multi-messenger high-energy astrophysics is the extension of the multi-wavelength exploration of the cosmos with multiple messengers with a common origin, including neutrinos, gravitational waves, and cosmic rays. This branch of astrophysics has currently achieved the potential to unravel the origin of cosmic rays and how sources accelerate them, their relation to the diffuse radiation in the extra-galactic space, and their role to forge their galaxies of origin while they wander in their magnetic fields for millions of years. Neutrino astronomy produced its major scientific milestone with the discovery by IceCube of a diffuse flux at energies above 60 TeV with intensity comparable to a predicted upper limit to the flux from extra-galactic sources of ultra-high energy cosmic rays. More recent results provide the first strong evidence of a standalone neutrino source and a highly probable coincidence of a neutrino alert with gamma rays. These results of IceCube indicate that neutrino astronomy can complement photon astronomy also providing insights into opaque sources of high-energy radiation. Starburst galaxies and jetted black holes in active galaxies are favored candidates to explain the diffuse cosmic neutrino background at > 60 TeV energies and its relation to the extragalactic background light. Additionally, gamma-ray bursts remain an intriguing mystery now enriched by joint observations of gamma-rays and gravitational waves. Ground-based detection of gamma-ray burst emissions with energies up to more than 10 TeV challenges the standard fireball model as well as the non-observation of neutrinos. The galactic diffuse flux, produced by cosmic ray interactions on the interstellar matter of our galaxy and peaking at lower energies, is within the reach of neutrino detectors. Together with the measured galactic gamma-ray flux up to PeV energies, they will shed light on the knee region of cosmic rays and the possible existence of dark matter in the Galactic plane. In the future, more work will be done in IceCube and deep sea and lake neutrino telescopes to use further low-energy cascades for cosmic source searches thanks to improved descriptions of detection media and deep learning methods. These aspects were discussed at the conference and are summarised in this write-up, and when necessary more recent results will be referred to.
1 citations
TL;DR: In this article , the first complete neutrino arrival direction reconstruction for detectors employing deep antennas such as RNO-G or planning to employ them like IceCube-Gen2 was described.
Abstract: Abstract In-ice radio detectors are a promising tool for the discovery of EeV neutrinos. For astrophysics, the implications of such a discovery will rely on the reconstruction of the neutrino arrival direction. This paper describes a first complete neutrino arrival direction reconstruction for detectors employing deep antennas such as RNO-G or planning to employ them like IceCube-Gen2. We will didactically introduce the challenges of neutrino direction reconstruction using radio emission in ice, elaborate on the detail of the algorithm used, and describe the obtainable performance based on a simulation study and discuss its implication for astrophysics.
1 citations
TL;DR: In this paper , the authors explore the possibility to use advanced germanium (Ge) detectors as a low-energy solar neutrino observatory by means of neutrinos-nucleus elastic scattering.
Abstract: Abstract We explore the possibility to use advanced germanium (Ge) detectors as a low-energy solar neutrino observatory by means of neutrino-nucleus elastic scattering. A Ge detector utilizing internal charge amplification for the charge carriers created by the ionization of impurities is a novel technology with experimental sensitivity for detecting low-energy solar neutrinos. Ge internal charge amplification (GeICA) detectors will amplify the charge carriers induced by neutrino interacting with Ge atoms through the emission of phonons. It is those phonons that will create charge carriers through the ionization of impurities to achieve an extremely low energy threshold of ∼0.01 eV. We demonstrate the phonon absorption, excitation, and ionization probability of impurities in a Ge detector with impurity levels of 3 × 10 10 cm −3 , 9 × 10 10 cm −3 , and 2 × 10 11 cm −3 . We present the sensitivity of such a Ge experiment for detecting solar neutrinos in the low-energy region. We show that, if GeICA technology becomes available, then a new opportunity arises to observe pp and 7 Be solar neutrinos. Such a novel detector with only 1 kg of high-purity Ge will give ∼10 events per year for pp neutrinos and ∼5 events per year for 7 Be neutrinos with a detection energy threshold of 0.01 eV.
1 citations
15 Feb 2023
TL;DR: In this article , the results achieved over the last decade on GRB neutrino searches with ANTARES data are presented, as well as preliminary KM3NeT performances to detect such transient neutrinos fluxes.
Abstract: Gamma-Ray Bursts (GRBs) are considered promising neutrino emitters. They appear as extremely intense bursts of gamma-ray radiation of extragalactic origin observed isotropically in the sky and constitute the most powerful explosions observable in the Universe. A lot has been learnt about these sources in the last years. However, their jet composition remains an open issue. Within the framework of the fireball model, mesons can be produced in photo-hadronic interactions occurring at internal shocks between shells emitted by the central engine. Following their decays, high-energy gamma rays and neutrinos are expected to be generated. By exploiting data collected by neutrino telescopes, temporal and spatial coincidences between high-energy neutrinos and GRBs can be searched for. In the context of identifying cosmic neutrino sources, an important role has been played over the last decade by ANTARES, the first undersea neutrino telescope located in the Northern hemisphere. Since investigations with ANTARES data have shown no coincidences, it was possible to set limits to the contribution of the detected GRB population to the diffuse neutrino flux, as well as to the neutrino emissions expected from bright GRBs and from the recently detected emitting TeV GRBs. GRBs are also interesting for KM3NeT, the next generation neutrino detectors under construction in two different sites of the Mediterranean Sea. Thanks to their geometry, both KM3NeT detectors will cover a broad neutrino energy range, from MeV to PeV, with a significant improvement as compared to ANTARES. This will enable us to further investigate GRB emissions, providing new insights into their possible neutrino production. In this contribution, the results achieved over the last decade on GRB neutrino searches with ANTARES data are presented, as well as preliminary KM3NeT performances to detect such transient neutrino fluxes.
1 citations
TL;DR: In this paper , the authors review scientific opportunities and challenges related to detection and reconstruction of low-energy (less than 100 MeV) signatures in liquid argon time-projection chamber (LArTPC) neutrino detectors.
Abstract: Abstract In this paper, we review scientific opportunities and challenges related to detection and reconstruction of low-energy (less than 100 MeV) signatures in liquid argon time-projection chamber (LArTPC) neutrino detectors. LArTPC neutrino detectors designed for performing precise long-baseline oscillation measurements with GeV-scale accelerator neutrino beams also have unique sensitivity to a range of physics and astrophysics signatures via detection of event features at and below the few tens of MeV range. In addition, low-energy signatures are an integral part of GeV-scale accelerator neutrino interaction final-states, and their reconstruction can enhance the oscillation physics sensitivities of LArTPC experiments. New physics signals from accelerator and natural sources also generate diverse signatures in the low-energy range, and reconstruction of these signatures can increase the breadth of Beyond the Standard Model scenarios accessible in LArTPC-based searches. A variety of experimental and theory-related challenges remain to realizing this full range of potential benefits. Neutrino interaction cross-sections and other nuclear physics processes in argon relevant to sub-hundred-MeV LArTPC signatures are poorly understood, and improved theory and experimental measurements are needed; pion decay-at-rest sources and charged particle and neutron test beams are ideal facilities for improving this understanding. There are specific calibration needs in the low-energy range, as well as specific needs for control and understanding of radiological and cosmogenic backgrounds. Low-energy signatures, whether steady-state or part of a supernova burst or larger GeV-scale event topology, have specific triggering, DAQ and reconstruction requirements that must be addressed outside the scope of conventional GeV-scale data collection and analysis pathways. Novel concepts for future LArTPC technology that enhance low-energy capabilities should also be explored to help address these challenges.
1 citations
TL;DR: In this article , the authors highlight the current status of IceCube-Gen2 with a focus on the in-ice radio array and propose a much enlarged surface array, including in-air radio antennas targeting air showers.
Abstract: Building on the success of IceCube at the South Pole, the next generation experiment IceCube- Gen2 is taking shape. Next to an extension of the optical array, further developing the optical detector learning for the IceCube-Upgrade currently in preparation, IceCube-Gen2 is planned to feature a large in-ice radio array targeting neutrinos beyond PeV energies. This radio array will build on heritage from many former and existing radio neutrino experiments. It will dominate the sensitivity of IceCube-Gen2 at EeV energies, improving at least an order of magnitude in sensitivity over existing arrays. IceCube-Gen2 will also feature a much enlarged surface array, including in-air radio antennas targeting air showers. This contribution will highlight the current status of IceCube-Gen2 with a focus on the in-ice radio array.
1 citations
TL;DR: The ICARUS-T600 Liquid Argon Time Projection Chamber (LAr-TPC) detector as discussed by the authors was the largest LAr detector ever built at that time, with almost 500 tons of active LAr.
Abstract: The Liquid Argon Time Projection Chamber (LAr-TPC) technology was conceived at the end of the 1970s as a way to combine the excellent spatial and calorimetric performance of the traditional bubble chambers with the electronic read-out of the TPCs, obtaining the so-called “electronic bubble chambers”. This technology was intended to be applied in particular to neutrino physics as an alternative to Ring Water Cherenkov detectors. The main technological issues of such an innovative technique were investigated from the very beginning within the ICARUS program, with staged R&D starting from prototypes of increasing mass to arrive, at the end of 1990s, at the largest LAr-TPC detector ever built at that time: ICARUS-T600, with almost 500 tons of active LAr. The successful operations of the ICARUS-T600 LAr-TPC in its more than twenty years of life, from the first run at surface in Pavia (Italy) in 2001 to the LNGS (Italy) underground run being exposed to the CNGS beam from CERN to Gran Sasso (2010–2013) and finally to the ongoing run at Fermilab (USA) for sterile neutrino searches (2020–), have demonstrated the huge potential of the LAr-TPC technique, paving the way to future larger LAr-TPCs detectors as DUNE.
16 Mar 2023
TL;DR: In this article , the authors considered the supernova neutrinos with tens of MeV and showed that the average Earth's core density can be determined within a factor of 10% at a confidence level at the Hyper-Kamiokande detector.
Abstract: Earth neutrino tomography is a realistic possibility with current and future neutrino detectors, complementary to geophysics methods. The two main approaches are based on either partial absorption of the neutrino flux as it propagates through the Earth (at energies about a few TeV) or on coherent Earth matter effects affecting the neutrino oscillations pattern (at energies below a few tens of GeV). In this work, we consider the latter approach focusing on supernova neutrinos with tens of MeV. Whereas at GeV energies, Earth matter effects are driven by the atmospheric mass-squared difference, at energies below $\sim 100$~MeV, it is the solar mass-squared difference what controls them. Unlike solar neutrinos, which suffer from significant weakening of the contribution to the oscillatory effect from remote structures due to the neutrino energy reconstruction capabilities of detectors, supernova neutrinos can have higher energies and thus, can better probe the Earth's interior. We shall revisit this possibility, using the most recent neutrino oscillation parameters and up-to-date supernova neutrino spectra. The capabilities of future neutrino detectors, such as DUNE, Hyper-Kamiokande and JUNO are presented, including the impact of the energy resolution and other factors. Assuming a supernova burst at 10~kpc, we show that the average Earth's core density could be determined within $\lesssim 10\%$ at $1\sigma$ confidence level, being Hyper-Kamiokande, with its largest mass, the most promising detector to achieve this goal.
TL;DR: In this article , three forms of a Convolutional Neural Network have been trained to reject cosmic muon events, classify beam events, and estimate neutrino energies, using only a slightly modified version of the raw detector event as input.
Abstract: Abstract This work presents a novel approach to water Cherenkov neutrino detector event reconstruction and classification. Three forms of a Convolutional Neural Network have been trained to reject cosmic muon events, classify beam events, and estimate neutrino energies, using only a slightly modified version of the raw detector event as input. When evaluated on a realistic selection of simulated CHIPS-5kton prototype detector events, this new approach significantly increases performance over the standard likelihood-based reconstruction and simple neural network classification.
02 Jun 2023
TL;DR: The LVD (Large Volume Detector) at the Low Background Laboratory, Gran Sasso, Italy, was built to detect neutrinos from stellar core collapses in our Galaxy as discussed by the authors .
Abstract: The LVD (Large Volume Detector), located at the Low Background Laboratory, Gran Sasso, Italy, is built to detect neutrinos from stellar core collapses in our Galaxy. The peculiarity of the search for rare events
requires close attention to the background of the experiment, such as the natural radioactivity of the rock and
detector materials and the interaction of cosmic ray muons underground. The LVD is capable of detecting
gamma quanta from the decay of radon daughter nuclei. We convincingly show the connection between the
change in the background counting rate from gammas in the detector and the change in the concentration of
radon nuclei in the experimental hall. We also point out the existence of another source of radon change, this
is seismic activity.
27 Apr 2023
TL;DR: In this article , the authors present an open-source simulation for neutrino telescopes, called Prometheus, which is written in a combination of C++ and Python and allows the user to simulate neutrinos with arbitrary geometry deployed in ice or water.
Abstract: Neutrino telescopes are gigaton-scale neutrino detectors comprised of individual light-detection units. Though constructed from simple building blocks, they have opened a new window to the Universe and are able to probe center-of-mass energies that are comparable to those of collider experiments. \prometheus{} is a new, open-source simulation tailored for this kind of detector. Our package, which is written in a combination of \texttt{C++} and \texttt{Python} provides a balance of ease of use and performance and allows the user to simulate a neutrino telescope with arbitrary geometry deployed in ice or water. \prometheus{} simulates the neutrino interactions in the volume surrounding the detector, computes the light yield of the hadronic shower and the out-going lepton, propagates the photons in the medium, and records their arrival times and position in user-defined regions. Finally, \prometheus{} events are serialized into a \texttt{parquet} file, which is a compact and interoperational file format that allows prompt access to the events for further analysis.
15 Feb 2023
TL;DR: The Radio Neutrino Observatory Greenland (RNO-G) as discussed by the authors detects in-ice radio waves emitted by neutrino induced particle showers in the Greenlandic ice sheet.
Abstract: In the ultra-high-energy (UHE) regime, the low predicted neutrino fluxes are out of reach for currently running neutrino detectors. Larger instrumented volumes are needed to probe these low fluxes. The Radio Neutrino Observatory Greenland (RNO-G) detects in-ice radio waves emitted by neutrino induced particle showers in the Greenlandic ice sheet. Radio waves have a large attenuation length ($\sim$1km), and therefore RNO-G implements a sparse instrumentation to cover an unprecedented volume. By 2022, seven stations have been deployed, consisting of a deep in-ice component and antennas just below the surface. Apart from measuring UHE neutrinos, RNO-G will be able to detect cosmic-ray air showers with a total effective area of close to $\mathcal{O}$(100km$^2$) above 0.1 EeV. Detected air showers can be used as a source for in-situ calibration of the detector and provide an important verification measurement due to the possible backgrounds. Prospects for in-ice signal detection of air showers are developing further: Simulations suggest energy dense cores which propagate though the ice and are visible to deep antennas. In addition, catastrophic energy losses from high energy air shower muons penetrating the ice may mimic the interaction of a neutrino. An efficient surface trigger will provide a veto mechanism for both types of events. The collected data of shallow and deep antennas can be used to verify simulations for in-ice development of air showers. This contribution introduces RNO-G, discusses lessons learned from the first year of data taking and outlines possible backgrounds.
TL;DR: The SBN program at Fermilab aims to measure νμ → νe neutrino oscillations at ∼ 1 km/GeV, resulting from the existence of a neutrinos mass eigenstate at 1 eV that does not interact weakly but participate at the oscillation phenomenon as mentioned in this paper .
Abstract: The SBN program at Fermilab aims to measure νμ → νe neutrino oscillations at ∼ 1 km/GeV, resulting from the existence of a sterile neutrino, namely a fourth neutrino mass eigenstate at 1 eV that does not interact weakly but participate at the oscillation phenomenon with the three standard neutrinos. The SBN Far Detector, ICARUS T600, was run at LNGS Lab from 2010 to 2013 as the first and largest LArTPC ever operated. At Fermilab ICARUS is at the surface and therefore a Cosmic Ray Tagger system is necessary in order to reject the cosmic ray background.
TL;DR: The Beamforming Elevated Array for COsmic Neutrinos (BEACON) as mentioned in this paper is a novel detector concept that utilizes a mountaintop radio interferometer to search for the radio emission due to these extensive air showers.
Abstract: When ultrahigh energy tau neutrinos skim the Earth, they can generate tau leptons that then decay in the atmosphere, forming upgoing extensive air showers. The Beamforming Elevated Array for COsmic Neutrinos (BEACON) is a novel detector concept that utilizes a mountaintop radio interferometer to search for the radio emission due to these extensive air showers. The prototype, located at the White Mountain Research Station in California, consists of 4 custom crossed-dipole antennas operating in the 30-80 MHz range and uses a directional interferometric trigger to achieve reduced thresholds and background rejection. The prototype will first be used to detect extensive air showers from down-going cosmic rays to validate the detector model. In this talk, we give an overview of the BEACON concept and the status of its prototype. We also discuss the ongoing cosmic ray search which utilizes both data analysis and simulation.
11 Apr 2023
TL;DR: In this paper , the authors developed a new analysis code, ''Supernova Parameter Estimation Code based on Insight on Analytic Late-time Burst Light curve at Earth Neutrino Detector (SPECIAL BLEND)''.
Abstract: Supernova neutrinos are invaluable signals that offer information about the interior of supernovae. Because a nearby supernova can occur at any time, preparing for future supernova neutrino observation is an urgent task. For the prompt analysis of supernova neutrinos, we have developed a new analysis code, ``Supernova Parameter Estimation Code based on Insight on Analytic Late-time Burst Light curve at Earth Neutrino Detector (SPECIAL BLEND)''. This code estimates the parameters of supernova based on an analytic model of supernova neutrinos from the proto-neutron star cooling phase. For easy availability to the community, this code is public and easily runs on web environments. SPECIAL BLEND can estimate the parameters better than the analysis pipeline we developed in the previous paper. By using SPECIAL BLEND, we can estimate the supernova parameters within $10\%$ precision up to $\sim 20\,{\rm kpc}$ and $\sim 60\,{\rm kpc}$ (Large Magellanic Cloud contained) with Super Kamiokande and Hyper Kamiokande, respectively.
29 Jun 2023
TL;DR: In this article , the authors put a limit on the number of Galactic sources required to explain the neutrino emission from the galactic plane with $>$4$\sigma$ significance.
Abstract: Galactic and extragalactic objects in the universe are sources of high-energy neutrinos that can be detected by the IceCube neutrino detector, with the former being easier to resolve due to comparatively smaller distances. Recently, a study done using cascade-like events seen by IceCube reported neutrino emission from the Galactic plane with $>$4$\sigma$ significance. In this work, we put a limit on the number of Galactic sources required to explain this emission. To achieve this, we make use of a simulation package created to simulate point sources in the Galaxy along with the neutrino and gamma-ray flux emissions originating from them. Along with making use of past IceCube sensitivity curves, we also account for Eddington bias effects due to Poisson fluctuations in the number of detected neutrino events. By making use of a toy-Monte Carlo simulation method, we find that there should be more than 10 sources, each with luminosities $10^{35}$ erg/s responsible for the Galactic neutrino emission. Our results constrain the number of individual point-like emission regions, which applies both to discrete astrophysical sources and to individual points of diffuse emission.
15 Feb 2023
TL;DR: In this paper , a developed, optimized, and tested algorithm for suppression of background cascades is presented for neutrino detector in the Gigaton Volume Detector (GVD) at Baikal-GVD.
Abstract: The neutrino telescope Baikal-GVD (Gigaton Volume Detector) has been designed to search for high-energy neutrino cosmic sources. It is located in pure water of Lake Baikal at a depth of 1366 m. Currently (year 2022) Baikal-GVD comprises 2880 optical modules divided to 10 independently operating clusters. Optical modules detect flashes of Cherenkov light from secondary charged particles induced in interactions of neutrinos with matter. Some charged and neutral current neutrino interactions lead to hadronic or electromagnetic cascade events. Apart from the neutrino cascades, the cascade-like light topologies can be also induced along the muon tracks. These event signatures, referred to as background cascades arise from the discrete stochastic energy losses of the muon. The cascades produced along the atmospheric muon bundles constitute the main background in neutrino cascade channel. In this paper, a developed, optimized, and tested algorithm for suppression of the background cascades is presented.
TL;DR: In this paper , an alternative method based on Convolutional Neural Network (CNN) has been developed to further increase that system's efficiency in event filtering, demonstrating the first successful application of DANN for CNN as an event classifier for a LArTPC.
Abstract: Abstract The Short Baseline Neutrino (SBN) program at Fermilab is an extensive experimental programme aiming at searching for sterile neutrino(s) [1], whose existence is one of the fundamental open questions of neutrino physics. It employs three Liquid Argon Time Projection Chamber (LArTPC) detectors, called ICARUS, MicroBooNE and SBND, sampling the Booster Neutrino Beam (BNB) at different locations from its target. The SBN detectors, working near the Earth’s surface, are subjected to a substantial cosmic background, which can mimic genuine neutrino interactions. Thus, it is essential to distinguish the signals related to the neutrino beams from those induced by the cosmic rays. The light detection system is a vital part of LArTPCs, but its role is even more critical for surface-operating detectors like ICARUS. The ICARUS light detection system is based on 360 Photomultiplier Tubes (PMTs). Its main role is to provide an efficient trigger and contribute to the 3D reconstruction of detected events. The light detection system calibration and further trigger system improvements were performed for the final detector configuration during the detector commissioning at Fermilab. The trigger system effectively exploits the information given by the PMTs. To further increase that system’s efficiency in event filtering, an alternative method based on Convolutional Neural Network (CNN) has been developed. Simulation-based results show that this technique can reduce the cosmic background by up to 76% with a neutrino selection efficiency of 99%. However, to filter the real data cases, which are usually not identical to the simulated ones, this method was improved by applying Domain Adversarial Neural Network (DANN). The results prove that adversarial training through a DANN can alleviate the simulation bias, demonstrating the first successful application of DANN for CNN as an event classifier for a LArTPC.
30 Apr 2023
TL;DR: In this article , the authors implemented the Bayesian inference to retrieve energy spectra of all neutrinos from a galactic core-collapse supernova (CCSN) and adopted a combination of several reaction channels from different large-scale neutrino observatories, such as inverse beta decay on proton and elastic scattering on electron from Hyper-Kamiokande (Hyper-K), charged current absorption on Argon from Deep Underground Neutrino Experiment (DUNE) and coherent elastic scatter on Lead from RES-NOVA.
Abstract: We implement the Bayesian inference to retrieve energy spectra of all neutrinos from a galactic core-collapse supernova (CCSN). To achieve high statistics and full sensitivity to all flavours of neutrinos, we adopt a combination of several reaction channels from different large-scale neutrino observatories, namely inverse beta decay on proton and elastic scattering on electron from Hyper-Kamiokande (Hyper-K), charged current absorption on Argon from Deep Underground Neutrino Experiment (DUNE) and coherent elastic scattering on Lead from RES-NOVA. Assuming no neutrino oscillation or specific oscillation models, we obtain mock data for each channel through Poisson processes with the predictions, for a typical source distance of 10 kpc in our Galaxy, and then evaluate the probability distributions for all spectral parameters of theoretical neutrino spectrum model with Bayes' theorem. Although the results for either the electron-neutrinos or electron-antineutrinos reserve relatively large uncertainties (according to the neutrino mass hierarchy), a precision of a few percent (i.e., $\pm 1 \% \sim \pm 4 \%$ at a credible interval of $2 \sigma$) is achieved for primary spectral parameters (e.g., mean energy and total emitted energy) of other neutrino species. Moreover, the correlation coefficients between different parameters are computed as well and interesting patterns are found. Especially, the mixing-induced correlations are sensitive to the neutrino mass hierarchy, which potentially makes it a brand new probe to determine the neutrino mass hierarchy in the detection of galactic supernova neutrinos. Finally, we discuss the origin of such correlation patterns and perspectives for further improvement on our results.
15 Jun 2023
TL;DR: In this article , the neutrino-induced event rate was found to be about 20% lower than expected with high statistical significance, assuming quantum decoherence of neutrinos in the gallium detectors at a scale of 2m.
Abstract: Gallium radioactive source experiments have reported a neutrino-induced event rate about 20\% lower than expected with a high statistical significance. We present an explanation of this observation assuming quantum decoherence of the neutrinos in the gallium detectors at a scale of 2~m. This explanation is consistent with global data on neutrino oscillations, including solar neutrinos, if decoherence effects decrease quickly with energy, for instance with a power law $E_
u^{-r}$ with $r\simeq 12$. Our proposal does not require the presence of sterile neutrinos but implies a modification of the standard quantum mechanical evolution equations for active neutrinos.
31 Jan 2023
TL;DR: In this paper , the parsec-scale jet structure of PKS 215+015 in total intensity and polarization was analyzed to constrain possible physical processes leading to neutrino emission in blazars.
Abstract: In the past years, evidence has started piling up that some high-energy cosmic neutrinos can be associated with blazars in flaring states. On February 26, 2022, a new blazar-neutrino coincidence has been reported: the track-like neutrino event IC220225A detected by IceCube is spatially coincident with the flat-spectrum radio quasar PKS 0215+015. Like previous associations, this source was found to be in a high optical and ${\gamma}$-ray state. Moreover, the source showed a bright radio outburst, which substantially increases the probability of a true physical association. We have performed six observations with the VLBA shortly after the neutrino event with a monthly cadence and are monitoring the source with the Effelsberg 100m-Telescope, and with the Australia Compact Telescope Array. Here, we present first results on the contemporary parsec-scale jet structure of PKS 0215+015 in total intensity and polarization to constrain possible physical processes leading to neutrino emission in blazars.
TL;DR: In this paper , an anti-neutrino detector (a prototype of VIDARR) was deployed at the Wylfa Magnox nuclear power station between 2014 and 2016.
Abstract: Abstract An anti-neutrino detector (a prototype of VIDARR) was deployed at the Wylfa Magnox nuclear power station between 2014 and 2016. It was comprised of extruded plastic scintillating bars measuring 4 cm by 1 cm by 152 cm and utilised wavelength shifting fibres (WLS) and Multi-Pixel Photon Counters (MPPCs) to detect and quantify radiation. During deployment, the detector recorded cosmic muon events in accidental coincidence along with the anti-neutrino events. The cosmic muons produced in the upper atmosphere had their paths obscured by the power plant buildings as the cosmic muons originated behind the buildings. Cosmic muons have a significantly higher probability to be attenuated and/or absorbed by denser objects and so one-sided muographic methods were utilised to image the reactor site buildings. In order to achieve clear building outlines a control data set was taken at the University of Liverpool from 2016 to 2018 which had minimal occlusion of the cosmic muon flux by dense objects. By taking the ratio of these two data sets and using GEANT4 simulations it is possible to perform a one-sided cosmic muon tomography analysis. This analysis can be used to discern specific buildings, building heights, and features at the Wylfa reactor site including the reactor core/reactor core shielding using cosmic-ray events equivalent to that which would be seen in ∼ 3 hours of normal operation. This result demonstrates the feasibility of using cosmic muon analysis to determine a segmented detector's location with respect to surrounding buildings, assisted by aerial photography or satellite imagery.
20 Jan 2023
TL;DR: The ICARUS detector at Fermilab has been used for neutrino experiments with the CERN Neutrino to Gran Sasso beam (CNGS) as discussed by the authors .
Abstract: The ICARUS collaboration employed the 760-ton T600 detector in a successful three-year physics run at the underground LNGS laboratory studying neutrino oscillations with the CERN Neutrino to Gran Sasso beam (CNGS) and searching for atmospheric neutrino interactions. ICARUS performed a sensitive search for LSND-like anomalous $
u_e$ 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 successfully completed its commissioning phase, collecting the first neutrino events from the Booster Neutrino Beam (BNB) and the Neutrinos at the Main Injector (NuMI) beam off-axis, which were used to test the ICARUS event selection, reconstruction and analysis algorithms. The first goal of the ICARUS data taking will then be a study to either confirm or refute the claim by Neutrino-4 short baseline reactor experiment both in the $
u_\mu$ channel with the BNB and in the $
u_e$ with NuMI. ICARUS will also address other fundamental studies such as neutrino cross sections with the NuMI beam and a number of Beyond Standard Model searches. After the first year of operations, ICARUS will commence its search for evidence of a sterile neutrino jointly with the Short Baseline Near Detector, within the Short-Baseline Neutrino program.
TL;DR: In this paper , the authors analyzed VLBI radio data of PKS 1424+240 taken with the Very Large Baseline Array at 15 GHz as part of the MOJAVE Survey.
Abstract: The true nature of sources of cosmic neutrinos recorded by the Antarctic IceCube Neutrino Detector is still an enigma of high-energy astrophysics. Time-integrated neutrino source searches with the 10 years of IceCube data unfolded neutrino hot-spots of the sky; among them, one is associated with the blazar PKS 1424+240, which is the third most significant neutrino source candidate in the Northern sky. In this paper, we analyze VLBI radio data of PKS 1424+240 taken with the Very Large Baseline Array at 15 GHz as part of the MOJAVE Survey. We generate the adaptively binned gamma-ray light curve of the source, employing Fermi-LAT data between 100 MeV and 300 GeV. We find that the VLBI jet components maintain quasi-stationary core separations at 15 GHz. We find a quiescence and a perturbed phase of the VLBI core of PKS 1424+240, based on that its Doppler factor increased tenfold after 2016 compared to the quiescence phase. We do not find elevated gamma-ray activity after 2016, while archive Swift-XRT measurements show a highly increased 0.3–10 keV X-ray flux in the beginning of 2017. Substantial increase of the activity of the radio core might help us to identify episodes of particle acceleration in lepto-hadronic blazar jets that eventually lead to the emission of high-energy neutrinos.
14 Apr 2023
TL;DR: The ARIANNA in-ice radio detector explores the detection of UHE neutrinos with shallow detector stations on the Ross Ice Shelf and the South Pole as discussed by the authors , and the results of these experiments lay the foundation for future large-scale experiments.
Abstract: The ARIANNA in-ice radio detector explores the detection of UHE neutrinos with shallow detector stations on the Ross Ice Shelf and the South Pole. Here, we present recent results that lay the foundation for future large-scale experiments. We show a limit on the UHE neutrino flux derived from ARIANNA data, measurements of the more abundant air showers, results from in-situ measurement campaigns, a study of a potential background from internal reflection layers, and give an outlook of future detector improvements.