Generation Of Neutrino Experiments Research Articles

Time-delayed neutrino emission from supernovae as a probe of dark matter-neutrino interactions

Thermal MeV neutrino emission from core-collapse supernovae offers a unique opportunity to probe physics beyond the Standard Model in the neutrino sector. The next generation of neutrino experiments, such as DUNE and Hyper-Kamiokande, can detect \U0001d4aa(103) and \U0001d4aa(104) neutrinos in the event of a Galactic supernova, respectively. As supernova neutrinos propagate to Earth, they may interact with the local dark matter via hidden mediators and may be delayed with respect to the initial neutrino signal. We show that for sub-MeV dark matter, the presence of dark matter-neutrino interactions may lead to neutrino echoes with significant time delays. The absence or presence of this feature in the light curve of MeV neutrinos from a supernova allows us to probe parameter space that has not been explored by dark matter direct detection experiments.

Rocks, water, and noble liquids: Unfolding the flavor contents of supernova neutrinos

Measuring core-collapse supernova neutrinos, both from individual supernovae within the Milky Way and from past core collapses throughout the Universe (the diffuse supernova neutrino background, or DSNB), is one of the main goals of current and next generation neutrino experiments. Detecting the heavy-lepton flavor (muon and tau types, collectively ${\ensuremath{\nu}}_{x}$) component of the flux is particularly challenging due to small statistics and large backgrounds. While the next galactic neutrino burst will be observed in a plethora of neutrino channels, allowing us to measure a small number of ${\ensuremath{\nu}}_{x}$ events, only upper limits are anticipated for the diffuse ${\ensuremath{\nu}}_{x}$ flux even after decades of data taking with conventional detectors. However, paleo detectors could measure the time-integrated flux of neutrinos from galactic core-collapse supernovae via flavor-blind neutral current interactions. In this work, we show how combining a measurement of the average galactic core-collapse supernova flux with paleo detectors and measurements of the DSNB electron-type neutrino fluxes with the next-generation water Cherenkov detector Hyper-Kamiokande and the liquid noble gas detector DUNE will allow to determine the mean supernova ${\ensuremath{\nu}}_{x}$ flux parameters with precision of order ten percent. Realizing this potential requires both the cosmic supernova rate out to $z\ensuremath{\sim}1$ and the integrated Galactic supernova rate over the last $\ensuremath{\sim}1\text{ }\text{ }\mathrm{Gyr}$ to be established at the $\ensuremath{\sim}10%$ level.

MicroBooNE and the νe Interpretation of the MiniBooNE Low-Energy Excess

A new generation of neutrino experiments is testing the 4.7σ anomalous excess of electronlike events observed in MiniBooNE. This is of huge importance for particle physics, astrophysics, and cosmology, not only because of the potential discovery of physics beyond the standard model, but also because the lessons we will learn about neutrino-nucleus interactions will be crucial for the worldwide neutrino program. MicroBooNE has recently released results that appear to disfavor several explanations of the MiniBooNE anomaly. Here, we show quantitatively that MicroBooNE results, while a promising start, unquestionably do not probe the full parameter space of sterile neutrino models hinted at by MiniBooNE and other data, nor do they probe the ν_{e} interpretation of the MiniBooNE excess in a model-independent way.

Synergies and prospects for early resolution of the neutrino mass ordering

The measurement of neutrino mass ordering (MO) is a fundamental element for the understanding of leptonic flavour sector of the Standard Model of Particle Physics. Its determination relies on the precise measurement of Delta m^2_{31} and Delta m^2_{32} using either neutrino vacuum oscillations, such as the ones studied by medium baseline reactor experiments, or matter effect modified oscillations such as those manifesting in long-baseline neutrino beams (LBnuB) or atmospheric neutrino experiments. Despite existing MO indication today, a fully resolved MO measurement (ge 5sigma) is most likely to await for the next generation of neutrino experiments: JUNO, whose stand-alone sensitivity is sim 3sigma, or LBnuB experiments (DUNE and Hyper-Kamiokande). Upcoming atmospheric neutrino experiments are also expected to provide precious information. In this work, we study the possible context for the earliest full MO resolution. A firm resolution is possible even before 2028, exploiting mainly vacuum oscillation, upon the combination of JUNO and the current generation of LBnuB experiments (NOvA and T2K). This opportunity is possible thanks to a powerful synergy boosting the overall sensitivity where the sub-percent precision of Delta m^2_{32} by LBnuB experiments is found to be the leading order term for the MO earliest discovery. We also found that the comparison between matter and vacuum driven oscillation results enables unique discovery potential for physics beyond the Standard Model.

Formula omitted] for light dark matter, gμ − 2, the 511 keV excess and the Hubble tension

In this paper we introduce a light Dirac particle ψ as thermal dark matter candidate in a U(1)Lμ−Lτ model. Together with the new gauge boson X, we find a possible parameter space with mX≃20 MeV, U(1)Lμ−Lτ coupling gX≃5⋅10−4 and mψ≳mX/2 where the (g−2)μ anomaly, dark matter, the Hubble tension, and (part of) the excess of 511 keV photons from the region near the galactic center can be explained simultaneously. This model is safe from current experimental and astrophysical constraints, but can be probed by the next generation of neutrino experiments as well as low–energy e+e− colliders.

Extracting low energy signals from raw LArTPC waveforms using deep learning techniques — A proof of concept

We investigate the feasibility of using deep learning techniques, in the form of a one-dimensional convolutional neural network (1D-CNN), for the extraction of signals from the raw waveforms produced by the individual channels of liquid argon time projection chamber (LArTPC) detectors. A minimal generic LArTPC detector model is developed to generate realistic noise and signal waveforms used to train and test the 1D-CNN, and evaluate its performance on low-level signals. We demonstrate that our approach overcomes the inherent shortcomings of traditional cut-based methods by extending sensitivity to signals with ADC values below their imposed thresholds. This approach exhibits great promise in enhancing the capabilities of future generation neutrino experiments like DUNE to carry out their low-energy neutrino physics programs.

Evaluation of neutron tagging performance in the Hyper-Kamiokande experiment

The Hyper-Kamiokande experiment is a next generation neutrino and nucleon-decay experiment. The experimental setup consists of a neutrino beam line and a huge Water Cherenkov detector. The detector is under construction towards the operation in 2027, and under optimization of its design especially around new photosensor modules, multi-PMTs. In this paper, I have evaluated a neutron tagging performance, which is one of the important techniques for the physics analysis, in the Water Cherenkov detector. The evaluation covers the relationship between the tagging efficiency and the configuration of the mPMTs.

Indirect dark matter searches at ultrahigh energy neutrino detectors

High to ultrahigh energy neutrino detectors can uniquely probe the properties of dark matter $\chi$ by searching for the secondary products produced through annihilation and/or decay processes. We evaluate the sensitivities to dark matter thermally averaged annihilation cross section $\langle\sigma v\rangle$ and partial decay width into neutrinos $\Gamma_{\chi\rightarrow\nu\bar{\nu}}$ (in the mass scale $10^7 \leq m_\chi/{\rm GeV} \leq 10^{15}$) for next generation observatories like POEMMA and GRAND. We show that in the range $ 10^7 \leq m_\chi/{\rm GeV} \leq 10^{11}$, space-based Cherenkov detectors like POEMMA have the advantage of full-sky coverage and rapid slewing, enabling an optimized dark matter observation strategy focusing on the Galactic center. We also show that ground-based radio detectors such as GRAND can achieve high sensitivities and high duty cycles in radio quiet areas. We compare the sensitivities of next generation neutrino experiments with existing constraints from IceCube and updated 90\% C.L. upper limits on $\langle\sigma v\rangle$ and $\Gamma_{\chi\rightarrow\nu\bar{\nu}}$ using results from the Pierre Auger Collaboration and ANITA. We show that in the range $ 10^7 \leq m_\chi/{\rm GeV} \leq 10^{11}$ POEMMA and GRAND10k will improve the neutrino sensitivity to particle dark matter by factors of 2 to 10 over existing limits, whereas GRAND200k will improve this sensitivity by two orders of magnitude. In the range $10^{11} \leq m_\chi/{\rm GeV} \leq 10^{15}$, POEMMA's fluorescence observation mode will achieve an unprecedented sensitivity to dark matter properties. Finally, we highlight the importance of the uncertainties related to the dark matter distribution in the Galactic halo, using the latest fit and estimates of the Galactic parameters.

SoLid: a short baseline reactor neutrino experiment

The SoLid experiment, short for Search for Oscillations with a Lithium-6 detector, is a new generation neutrino experiment which tries to address the key challenges for high precision reactor neutrino measurements at very short distances from a reactor core and with little or no overburden. The primary goal of the SoLid experiment is to perform a precise measurement of the electron antineutrino energy spectrum and flux and to search for very short distance neutrino oscillations as a probe of eV-scale sterile neutrinos. This paper describes the SoLid detection principle, the mechanical design and the construction of the detector. It then reports on the installation and commissioning on site near the BR2 reactor, Belgium, and finally highlights its performance in terms of detector response and calibration.

Ultrahigh-energy tau neutrino cross sections with GRAND and POEMMA

Next generation neutrino experiments will push the limits in our understanding of astroparticle physics in the neutrino sector to energies orders of magnitude higher than the current state-of-the-art high-energy neutrino experiment, IceCube. These experiments will use neutrinos to tell us about the most extreme environments in the universe, while simultaneously leveraging these extreme environments as probes of neutrino properties at the highest energies accessible in the foreseeable future: $E\sim10^9$ GeV. At these energies neutrinos are readily absorbed in the Earth. Assuming an isotropic distribution, by looking at how the flux varies as a function of angle through the Earth, we show that it is possible to extract the $\nu_\tau$-$N$ cross section with precision at the $\sim20\%$ level ($1\sigma$ assuming Wilks' theorem) given $N_{\rm events}\sim100$ events.

Astroparticle Physics in Hyper-Kamiokande

Hyper-Kamiokande (Hyper-K) is a proposed next generation neutrino experiment, aiming at the measurement which starts at 2027. Hyper-K project includes a high intensity accelerator neutrino beamline at J-PARC and large water Cherenkov far detectors. Each detector will provide the fiducial volume of 0.19 Mt ultra-pure water. Due to its world-largest water volume, superior performance of the new photodetector and the location at deep underground, Hyper-K will also have great capability for neutrino astrophysics and push back the frontiers. Here, the Hyper-K’s detector performance for MeV neutrinos will be shown. Then the issues for neutrino astrophysics and our reach will be discussed, i.e., for solar neutrino, supernova burst neutrino and supernova relic neutrino observations.

Short analysis of cosmogenic production of radioactive isotopes in argon as target for the next neutrino experiments

The reduction of the radioactive background, the knowledge of its sources and mechanisms of its production, as well as the characteristics of its signals represent important steps for the next generation neutrino experiments, because thus the sensitivity of huge detectors is increased, and also the capability to discriminate between various particles interacting with the detector. Liquid - gaseous argon as LAr TPC technology represents a major option as target and an excellent tracking - calorimeter detector. In this class of detectors, both the scintillation light emitted and the charges produced by ionization are used to detect and identify the characteristics of the primary and secondary particles. Cosmogenic sources of background or activation of different materials become more important in this context. The radioactivity induced by cosmogenic reactions in Ar is discussed by considering muon capture and reactions induced by neutrons as sources of background. The ratio between the vertical and horizontal components of the very low energy terrestrial muons at ground level is measured in a particular location and the total flux of the low energy component of muon spectra is estimated using the EXPACS code, developed in the frame of the PARMA model. For neutron interactions, only the simulated cross sections for possible production of radioactive isotopes of argon are considered using the TALYS and EMPIRE software codes, highlighting the similarities and differences between the results of these nuclear codes and the level of concordance with the few existing experimental data. A short discussion about the scintillation processes in the argon bulk and the possible effects due of the presence of radioactive isotopes is presented.

Recent Results of the ANTARES Neutrino Telescope

The discovery of cosmic neutrinos of astrophysical origin by IceCube has started a new chapter in the field of Neutrino Astronomy. Noticeably, a small accumulation of events in the region near the Galactic Centre has been observed: a telescope in the Mediterranean Sea constitutes a great opportunity for the physics quest, since it offers a perfect complementarity to IceCube and, in particular, a better visibility of the Galactic Centre. ANTARES (Astronomy with a Neutrino Telescope and Abyss Environmental RESearch) is the first operational Cherenkov neutrino telescope in the Mediterranean Sea and the largest neutrino detector in the Northern hemisphere, covering an area of about 0.1 km2; located 40 km offshore Toulon, France, at a depth of 2475 m, it has been completed in June 2008 and it is currently taking data. It consists of a tri-dimensional array of 885 photo-multipliers tubes (PMTs), distributed in 12 lines. ANTARES has recently performed a search for an excess of high energy neutrinos in the direction of the Galactic Centre, close to the accumulation of the IceCube events, assuming both the hypotheses of a point-like and an extended neutrino source. The results of this search will be discussed in this contribution, together with other recent achievements of the experiment, as the search for point-like sources, the results on the diffuse flux of cosmic neutrino signal and the search for neutrino emission from the Fermi bubbles. ANTARES offers a first view of the Neutrino Sky from the Northern hemisphere; its successful operation and its promising results make more compelling the expectations for KM3NeT, the next generation neutrino experiment in the Mediterranean Sea.

Neutrino oscillation studies with IceCube-DeepCore

IceCube, a gigaton-scale neutrino detector located at the South Pole, was primarily designed to search for astrophysical neutrinos with energies of PeV and higher. This goal has been achieved with the detection of the highest energy neutrinos to date. At the other end of the energy spectrum, the DeepCore extension lowers the energy threshold of the detector to approximately 10 GeV and opens the door for oscillation studies using atmospheric neutrinos. An analysis of the disappearance of these neutrinos has been completed, with the results produced being complementary with dedicated oscillation experiments. Following a review of the detector principle and performance, the method used to make these calculations, as well as the results, is detailed. Finally, the future prospects of IceCube-DeepCore and the next generation of neutrino experiments at the South Pole (IceCube-Gen2, specifically the PINGU sub-detector) are briefly discussed.

First measurement of radioactive isotope production through cosmic-ray muon spallation in Super-Kamiokande IV

Cosmic-ray-muon spallation-induced radioactive isotopes with $\beta$ decays are one of the major backgrounds for solar, reactor, and supernova relic neutrino experiments. Unlike in scintillator, production yields for cosmogenic backgrounds in water have not been exclusively measured before, yet they are becoming more and more important in next generation neutrino experiments designed to search for rare signals. We have analyzed the low-energy trigger data collected at Super-Kamiokande-IV in order to determine the production rates of $^{12}$B, $^{12}$N, $^{16}$N, $^{11}$Be, $^9$Li, $^8$He, $^9$C, $^8$Li, $^8$B and $^{15}$C. These rates were extracted from fits to time differences between parent muons and subsequent daughter $\beta$'s by fixing the known isotope lifetimes. Since $^9$Li can fake an inverse-beta-decay reaction chain via a $\beta + n$ cascade decay, producing an irreducible background with detected energy up to a dozen MeV, a dedicated study is needed for evaluating its impact on future measurements; the application of a neutron tagging technique using correlated triggers was found to improve this $^9$Li measurement. The measured yields were generally found to be comparable with theoretical calculations, except the cases of the isotopes $^8$Li/$^8$B and $^9$Li.

The LAGUNA/LBNO potential for Long Baseline neutrino physics

The LAGUNA/LBNO collaboration proposes a new generation neutrino experiment to address fundamental questions in particle and astroparticle physics. The experiment consists of a far detector, Liquid Argon (LAr) double phase Time TPC (Time Projection Chamber), the fiducial mass of the detector is set to 20 kt in its first stage. The detector will be situated at 2300 km from CERN: this long baseline provides a unique opportunity to study the neutrino flavour oscillations over the first and second oscillation maxima and to explore the L/E (Length over energy) behaviour. The near detector is based on a high-pressure argon gas TPC situated at CERN. I will detail the physics potential of this experiment for determining without ambiguity the mass hierarchy (MH) in its first stage and discovering CP violation (CPV) using the CERN SPS beam with a power of 750 kw. The impact of the assumptions on the knowledge of the oscillation parameters and the systematic errors are very important and will be shown in detail to prove the force of the experiment assuming realistic and conservative parameter values.

Development of a Liquid Scintillator Using Water for a Next Generation Neutrino Experiment

A feasibility study on a new type of liquid scintillator based on water has been performed. Mainly due to the differences in polarities between water and oil, organic solvents are not mixed in water. In order to make a liquid scintillator based on water, a surfactant that contains hydrophilic and hydrophobic groups is used. The surfactant keeps water and organic solvents apart in solution. Good physical and optical parameters and long-term stability are required to use liquid scintillator based on water in massive detector for the next generation neutrino experiments. In this paper, we report the characteristics and the possibility of liquid scintillators using water with various new surfactants.

Beams for the Intensity Frontier of Particle Physics

Advances in high intensity beams have driven particle physics forward since the inception of the field. State-of-the-art and next generation high intensity beams will drive experiments searching for ultrarare processes sensitive through quantum corrections to new particle states far beyond the reach of direct production in foreseeable beam colliders. The recent discovery of the ultrarare B meson decay Bs → μμ, with a branching fraction of 3 × 10-9 for example, has set stringent limits on new physics within direct reach of the Large Hadron Collider. Today, even in the context of the Higgs boson discovery, observation of finite neutrino masses is the only laboratory evidence of physics beyond the Standard Model of particle physics. The tiny mass scale of neutrinos may foretell and one day expose physics that connects quarks and leptons together at the "grand unification" scale and may be the portal through which our world came to the matter-dominated state so different from conditions we expect in the early universe. Here we describe next generation neutrino and rare processes experiments that will deeply probe these and other questions central to the field of particle physics.

Using Large Area Microchannel Plate Photodetectors in the Next Generation Water Cherenkov Neutrino Detectors

The next generation of neutrino experiments will require massive water Cherenkov detectors to reach the sensitivity needed to measure CP violation in the lepton sector and the neutrino mass hierarchy. The Large Area Picosecond Photodetector Development (LAPPD) Collaboration is developing new methods to fabricate a 20 cm2 thin planar microchannel plate photo-multiplier tube (MCP) at a cost comparable to those of traditional photomultiplier tubes (PMT). The application of these novel devices to large water Cherenkov detectors could significantly enhance background rejection and vertex resolution in these detectors by improving spatial and timing information. We present details of the MCP fabrication method, and preliminary results from testing and characterization facilities at Argonne National Laboratory. The application of these devices to neutrino detectors is also discussed.

SU(3) gauge family symmetry and prediction for the lepton-flavor mixing and neutrino masses with maximal spontaneous CP violation

A model for the lepton-flavor mixing and CP violation is proposed based on the SUF(3) gauge family symmetry and the Majorana feature of neutrinos. A consistent prediction for the lepton-flavor mixing and masses is shown to be resulted from the appropriate vacuum structure of SUF(3) gauge symmetry breaking. By choosing the SUF(3) gauge fixing condition to possess a residual Z2 symmetry and requiring the vacuum structure of spontaneous symmetry breaking to have approximate global U(1) family symmetries, we obtain naturally the tri-bimaximal mixing matrix and largely degenerate neutrino masses in the neutrino sector and the small mixing matrix in the charged-lepton sector. With a simple ansatz that all the smallness due to the approximate global U(1) family symmetries is characterized by a single Wolfenstein parameter λ≃0.22, and the charged-lepton mixing matrix has a similar hierarchy structure as the CKM quark mixing matrix, we arrive at a consistent prediction for the MNSP lepton-flavor mixing with a maximal spontaneous CP violation: δ=π/2, sin2θ13≃12λ2≃0.024 (sin22θ13≃0.094), sin2θ12≃13(1−2λ3)≃0.326 and sin2θ23≃12(1−λ2)≃0.48, which agree well with the current experimental data. The CP-violating Jarlskog-invariant is obtained to be JCP≃16λ(1−λ2/2−λ3)sinδ≃0.035, which is detectable in next generation neutrino experiment. The small masses of the neutrinos and charged leptons are simply attributed to the standard seesaw mechanism. The largely degenerate neutrino masses with the normal hierarchy and inverse hierarchy are discussed and found to be at the order mνi≃O(λ2)≃0.04–0.06 eV with a total mass ∑mν∼0.15 eV, which is testable in future precision astrophysics and cosmology.