Supernova Neutrino Detection Research Articles

The Sun and core-collapse supernovae are leading probes of the neutrino lifetime

The large distances travelled by neutrinos emitted from the Sun and core-collapse supernovae together with the characteristic energy of such neutrinos provide ideal conditions to probe their lifetime, when the decay products evade detection. We investigate the prospects of probing invisible neutrino decay capitalising on the detection of solar and supernova neutrinos as well as the diffuse supernova neutrino background (DSNB) in the next-generation neutrino observatories Hyper-Kamiokande, DUNE, JUNO, DARWIN, and RES-NOVA.We find that future solar neutrino data will be sensitive to values of the lifetime-to-mass ratio τ 1/m 1 and τ 2/m 2 of 𝒪(10-1–10-2) s/eV. From a core-collapse supernova explosion at 10 kpc, lifetime-to-mass ratios of the three mass eigenstates of 𝒪(105) s/eV could be tested. After 20 years of data taking, the DSNB would extend the sensitivity reach of τ 1/m 1 to 108 s/eV. These results promise an improvement of about 6–15 orders of magnitude on the values of the decay parameters with respect to existing limits.

JUNO Experiment: Current Status and Physics

JUNO is a 20 kt liquid scintillator detector located ∼650 m underground in Jiangmen, China. The construction will be finished in 2023. Its energy resolution can reach 3% at 1 MeV, which allows it to realize its main goal of determining the neutrino mass ordering (NMO) detecting antineutrinos from two nuclear power plants at 53 km baseline. Mass ordering is expected to have 3 σ of significance in 6 years of data taking. Meanwhile the measurement of oscillation parameters sin2 θ 12, , and will reach sub-percent precision. The Taishan Antineutrino Observatory will be placed ∼30 m from the core of one power plant, in order to measure the reactor antineutrino spectrum, as a reference spectrum for the determination of NMO in JUNO, with resolution better than 2% at 1 MeV. The OSIRIS pre-detector is designed to monitor the LS of JUNO during the several months of filling. With its massive LS volume and excellent energy resolution, JUNO will be able to explore many other neutrino, astro, and particle physics topics. For example, detection of supernova neutrinos, atmospheric neutrinos, solar neutrinos, and geoneutrinos. This paper reviews the current status of JUNO and introduces recent studies on JUNO’s potential in many different physics topics.

Bayesian inference of supernova neutrino spectra with multiple detectors

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 ordering), a precision of a few percent (i.e., ±1% ∼ ±4% at a credible interval of 2σ) 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 ordering, which potentially makes it a brand new probe to determine the neutrino mass ordering in the detection of galactic supernova neutrinos. Finally, we discuss limitations and perspectives for further improvement on our results.

Neutrino-induced reactions on 18O and implications of 18O mixture in water Cherenkov detectors on supernova neutrino events

Neutrino-nucleus reaction cross sections on 18O are evaluated by shell-model calculations and compared with those on 16O. Important contributions from Gamow-Teller transitions are noticed for 18O (νe, e−) 18F in contrary to the case for 16O, where spin-dipole transitions are dominant contributions. Calculated cross sections for 18O (νe, e−) 18F are shown to be larger than for 16O at low neutrino energies below 20 MeV in natural water with the 0.205% admixture of 18O due to the lower threshold energy (1.66 MeV) for 18O than that for 16O (15.42 MeV). The resulting electron spectra, that is, the cross sections as functions of emitted electron energy Te, are also shown to be quite different, reflecting the different threshold energies. The electron spectra from (νe, e−) reactions on 18O and 16O in water Cherenkov detectors for supernova neutrino detection are investigated for both the cases with and without the neutrino oscillation and compared with those of the neutrino-electron scattering. It has been shown that the contribution from 18O (0.205% mixture) enhances the rates from 16O by 60% for the case without the oscillation and by 20-30% for the case with the oscillation below Te =20 MeV. For the case with the neutrino oscillation, the event rates for 18O and 16O become comparable to those of the neutrino-electron scattering. However, their rates at low energy (Te< 20 MeV) are much lower than those of the neutrino-electron scattering, which is important for the pointing accuracy to the supernova direction.

Identification and reconstruction of low-energy electrons in the ProtoDUNE-SP detector

Measurements of electrons from νe interactions are crucial for the Deep Underground Neutrino Experiment (DUNE) neutrino oscillation program, as well as searches for physics beyond the standard model, supernova neutrino detection, and solar neutrino measurements. This article describes the selection and reconstruction of low-energy (Michel) electrons in the ProtoDUNE-SP detector. ProtoDUNE-SP is one of the prototypes for the DUNE far detector, built and operated at CERN as a charged particle test beam experiment. A sample of low-energy electrons produced by the decay of cosmic muons is selected with a purity of 95%. This sample is used to calibrate the low-energy electron energy scale with two techniques. An electron energy calibration based on a cosmic ray muon sample uses calibration constants derived from measured and simulated cosmic ray muon events. Another calibration technique makes use of the theoretically well-understood Michel electron energy spectrum to convert reconstructed charge to electron energy. In addition, the effects of detector response to low-energy electron energy scale and its resolution including readout electronics threshold effects are quantified. Finally, the relation between the theoretical and reconstructed low-energy electron energy spectra is derived, and the energy resolution is characterized. The low-energy electron selection presented here accounts for about 75% of the total electron deposited energy. After the addition of lost energy using a Monte Carlo simulation, the energy resolution improves from about 40% to 25% at 50 MeV. These results are used to validate the expected capabilities of the DUNE far detector to reconstruct low-energy electrons.3 MoreReceived 3 November 2022Accepted 27 April 2023DOI:https://doi.org/10.1103/PhysRevD.107.092012Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasParticle interactionsPhysical SystemsElectronsLeptonsMuonsNeutrinosPositronsTechniquesMonte Carlo methodsNeutrino detectorsParticle acceleratorsParticle data analysisParticle decaysParticle detectorsParticles & Fields

Online triggers for supernova and pre-supernova neutrino detection with cryogenic detectors

Supernovae (SNe) are among the most energetic events in the universe still far from being fully understood. An early and prompt detection of neutrinos is a one-time opportunity for the realization of the first multi-messenger observation of these events. In this work, we present the prospects of detecting neutrinos produced before (pre-SN) and during a SN while running an advanced cryogenic detector. Recent advances in the cryogenic detector technique and the discovery of coherent elastic neutrino-nucleus scattering offer a wealth of opportunities in neutrino detection. The combination of the excellent energy resolution of this experimental technique, with the high cross section of this detection channel and its equal sensitivity to all neutrino flavors, enables the realization of highly sensitive neutrino telescopes of the size of a few tens of cm, as the newly proposed RES-NOVA experiment. We present a detailed study on the detection promptness of pre-SN and SN neutrino signals, with direct comparisons among different classes of test statistics. While the well-established Poisson test offers in general best performance under optimal conditions, the nonparametric Recursive Product of Spacing statistical test (RPS) is more robust for triggering astrophysical neutrino signals with no specific prior knowledge. Based on our statistical tests the RES-NOVA experiment is able to identify SN neutrino signals at a 15 kpc distance with 95% of success rate, and pre-SN signal as far as 450 pc with a pre-warn time of the order of 10 s. These results demonstrate the potential of RPS for the identification of neutrino signals and the physics reach of the RES-NOVA experiment.

Enhanced low-energy supernova burst detection in large liquid argon time projection chambers enabled by Q-Pix

The detection of neutrinos from core-collapse supernovae may reveal important process features as well as neutrino properties. The detection of supernova neutrinos is one of the main science drivers for future kiloton-scale neutrino detectors based on liquid argon. Here we show that for such detectors the intrinsically 3D readout in Q-Pix offers numerous advantages relative to a wire-based readout, such as higher reconstruction efficiency, lower energy threshold, considerably lower data rates, and potential pointing information.

Measurements of gamma ray, cosmic muon and residual neutron background fluxes for rare event search experiments at an underground laboratory

Ambient radiation background contributed by the penetrating cosmic ray particles and the radionuclides present in the rock materials have been measured at an underground laboratory at Jaduguda, Jharkhand, India, located inside a mine at 555 m depth. The laboratory is being set up to explore rare event search processes, such as direct dark matter search, neutrinoless double beta decay, axion search, supernova neutrino detection, etc., that require specific knowledge of the nature and extent of the radiation environment in order to assess the sensitivity reach and also to plan for its reduction for the targeted experiment. The gamma ray background, which is mostly contributed by the primordial radionuclides and their decay chain products, have been measured inside the laboratory and found to be dominated by rock radioactivity for Eγ≲3MeV. Shielding of these residual gamma rays for the experiment was also evaluated. The cosmic muon flux, measured inside the laboratory using large area plastic scintillator telescope, was found to be: (2.257±0.261±0.042)×10−7cm−2s−1, which agrees reasonably well with simulation results. The neutron background flux has been measured for the radiogenic neutrons and found to be: (1.61±0.03)×10−4cm−2s−1 for no threshold cut. Detailed GEANT4 simulation for the radiogenic neutrons and the cosmogenic neutrons have been carried out. Effects of multiple scattering of both the types of neutrons within the surrounding rock and the cavern walls were studied and the results for the radiogenic neutrons are found to be in reasonable agreement with experimental results. Neutron fluxes contributed by those neutrons of cosmogenic origin have been reported as function of the energy threshold.

Neutrino Echos following Black Hole Formation in Core-collapse Supernovae

Abstract During a failed core-collapse supernova, the protoneutron star eventually collapses under its own gravitational field and forms a black hole. This collapse happens quickly, on the dynamical time of the protoneutron star, ≲0.5 ms. During this collapse, barring any excessive rotation, the entire protoneutron star is accreted into the newly formed black hole. The main source of neutrinos is now removed and the signal abruptly shuts off over this formation timescale. However, while the source of neutrinos is turned off, the arrival times at an Earth-based detector will depend on the neutrino path. We show here that a modest amount of neutrinos, emitted just prior to the black hole forming, scatter on the infalling material into our line of sight and arrive after the formation of the black hole, up to 15 ms in our model. This neutrino echo, which we characterize with Monte Carlo simulations and analytic models, has a significantly higher average energy (upwards of ∼50 MeV) compared to the main neutrino signal, and for the canonical failed supernova explored here, is likely detectable in  (10 kT) supernova neutrino detectors for Galactic failed supernovae. The presence of this signal is important to consider if using black hole formation as a time post for triangulation or the post black hole timing profile for neutrino mass measurements. On its own, it can also be used to characterize or constrain the structure and nature of the accretion flow.

Combined detection of supernova neutrino signals

Supernova neutrino detection in neutrino and dark matter experiments is usually implemented as a real-time trigger system based on counting neutrino interactions within a moving time window. The sensitivity reach of such experiments can be improved by taking into account the time profile of the expected signal. We propose a shape analysis of the incoming experimental data based on a log likelihood ratio variable containing the assumed signal shape. This approach also allows a combination of potential supernova signals in different detectors for a further sensitivity boost. The method is tested on the NOvA detectors to study their combined sensitivity to the core-collapse supernova signal, and also on KamLAND, Borexino and SK-Gd as potential detectors of presupernova neutrinos. Using the shape analysis enhances the signal significance for supernova detection and prediction, as well as the sensitivity reach of the experiment. It also extends the supernova prediction time when applied to the presupernova neutrino signal detection. Enhancements achieved with the shape analysis persist even in the case when the actual signal doesn't match the expected signal model.

JUNO Detector Design & Status

The Jiangmen Underground Neutrino Observatory (JUNO) is a next-generation liquid-scintillator reactor neutrino experiment under construction in Southern China. It is a multi-purpose experiment with a wide range of applications in neutrino physics, ranging from a neutrino mass ordering (NMO) determination, the detection of solar, geo-, atmospheric neutrinos, and Supernova neutrinos, to the measurement on particular oscillation parameters with sub-percentage precision. The JUNO central detector (CD) is designed to reach an energy resolution of 3% at 1MeV. The detector is being installed in a recently excavated experimental hall, 50 m wide and located under 700 m of granite overburden (1800 m.w.e.). The CD contains a 35.4-meter diameter acrylic vessel filled with 20-kt of LAB-based liquid scintillator, making it the largest liquid-scintillator detector of its kind in the world. The scintillation light will be read-out by 17612 20” photomultiplier tubes (PMTs) and 25600 3” PMTs, reaching a photocathode coverage higher than 75%. A water pool filled with ultrapure water equipped with 2,400 PMTs surrounds the CD; on top of the water pool, a 3-layer plastic scintillator tracker completes the JUNO veto system for cosmic muons detection. JUNO construction will be completed in 2022. This talk presents the detector design and status of the experiment.

Supernova Neutrino Burst Search at KamLAND

We report a result of supernova neutrino burst search at KamLAND in a neutrino energy range of 1.8–111 MeV via the inverse-beta decay (IBD). The search was performed using data from 2002 March 9th to 2020 July 17th, and the corresponding livetime is 5001.21 days. We searched for two or more sequential IBD events within 10 s as a supernova neutrino burst candidate. The dominant background is the accidental cluster of 2 or more IBD events caused by neutrinos from other sources, though, which are estimated to be almost negligible. We evaluated detectable ranges for some emitted supernova neutrino burst models. The conservative detectable ranges are 38kpc for core-collapse supernova (ccSN) and 42kpc for failed ccSN. We found no significant supernova neutrino burst events and set a 90% upper limit on the supernova neutrino detection rate in KamLAND as 0.178 burst/yr.

Liquid argon characterization of the X-ARAPUCA with alpha particles, gamma rays and cosmic muons

The X-ARAPUCA device is the baseline choice for the photon detection system of the first far detector module of the DUNE experiment. We present the results of the first complete characterization of a small scale X-ARAPUCA prototype, which is a slice of a full DUNE module. Its total detection efficiency in liquid argon was measured with three different ionizing radiations: α particles, γ's and muons and resulted to be ∼2.2% when the active silicon photomultipliers were biased at +5.0 V of over voltage, corresponding to a Photon Detection Efficiency around 50% at room temperature. This value comfortably satisfies the requirements of the first DUNE far detector module (detection efficiency >2.0%) and allows to achieve an energy resolution comparable to the one achievable with the Time Projection Chambers for energies below 10 MeV, which is the region relevant for Supernova neutrino detection.

Supernova neutrino detection through neutron emission by nuclei

Neutrinos from core collapse supernovae can excite nuclei of some detector materials beyond their neutron emission thresholds. Detection of these neutrons can give valuable information about the supernova explosion mechanism and possibly also throw light on neutrino properties. In this article, we give a brief review of the basic physics of neutrino induced neutron emission and describe the results of some recent calculations of supernova neutrino induced neutrons for some specific target detector materials due to charged current (CC) interactions of the electron flavored neutrinos and antineutrinos as well as due to neutral current (NC) interactions of neutrinos and antineutrinos of all flavors with the detector nuclei. We highlight the fact that a detector material such as lead with a relatively large neutron excess produces neutrons dominantly through the CC interaction of the $\nu_e$s, whereas a material such as iron with small neutron excess produces neutrons dominantly through the combined NC interaction of all the six neutrino and antineutrino species. This raises the interesting possibility of probing the fraction of mu- and tau flavored neutrinos (which interact only through NC interaction) in the supernova neutrino flux by means of simultaneous detection of a supernova in a lead and an iron detector, for example.

Developing an end-to-end simulation framework of supernova neutrino detection

Abstract Massive stars can explode as supernovae at the end of their life cycle, releasing neutrinos whose total energy reaches $10^{53}{\rm\, erg}$. Moreover, neutrinos play key roles in supernovae, heating and reviving the shock wave as well as cooling the resulting proto-neutron star. Therefore, neutrino detectors are waiting to observe the next galactic supernova, and several theoretical simulations of supernova neutrinos are underway. While these simulations concentrate mainly on only the first second after the supernova bounce, the only observation of a supernova with neutrinos, SN 1987A, revealed that neutrino emission lasts for more than 10 seconds. For this reason, long-time simulation and analysis tools are needed to compare theories with the next observation. Our study develops an integrated supernova analysis framework to prepare an analysis pipeline for treating galactic supernovae observations in the near future. This framework deals with the core-collapse, bounce, and proto-neutron star cooling processes, as well as with neutrino detection on Earth in a consistent manner. We have developed a new long-time supernova simulation in one dimension that explodes successfully and computes the neutrino emission for up to 20 seconds. Using this model we estimate the resulting neutrino signal at the Super-Kamiokande detector to be about 1800 events for an explosion at 10 kpc, and we discuss the implications of this. We compare this result with the SN 1987A observation to test its reliability.

Neutrino-nucleus reactions on oxygen and neon for nucleosynthesis and supernova neutrino detection

Spin-dipole strength in 16O and ν-induced reactions on 16O are studied by shell-model calculations. Charged- and neutral-current reaction cross sections for various particle and γ emission channels as well as the total ones are evaluated with the Hauser-Feshbach statistical method. Nucleosynthesis of 11B and 11C in supernovae through αp emission channels is investigated. Charged-current reaction cross sections induced by supernova ν and their dependence on ν oscillations are discussed for future supernova burst. Neutrino-nucleus reaction cross sections on 20Ne induced by Gamow-Teller and spin-dipole transitions are also investigated. Electron-capture rates for the forbidden transition 20Ne (e-, νe) 20F (2g.s. +) at stellar environments are discussed.

Core-collapse supernova neutrino emission and detection informed by state-of-the-art three-dimensional numerical models

ABSTRACT Based on our recent three-dimensional core-collapse supernova (CCSN) simulations including both exploding and non-exploding models, we study the detailed neutrino signals in representative terrestrial neutrino observatories, namely Super-Kamiokande (Hyper-Kamiokande), DUNE, JUNO, and IceCube. We find that the physical origin of difference in the neutrino signals between 1D and 3D is mainly proto-neutron-star convection. We study the temporal and angular variations of the neutrino signals and discuss the detectability of the time variations driven by the spiral standing accretion shock instability (spiral SASI) when it emerges for non-exploding models. In addition, we determine that there can be a large angular asymmetry in the event rate (${\gtrsim} 50 {{\ \rm per\ cent}}$), but the time-integrated signal has a relatively modest asymmetry (${\lesssim} 20 {{\ \rm per\ cent}}$). Both features are associated with the lepton-number emission self-sustained asymmetry and the spiral SASI. Moreover, our analysis suggests that there is an interesting correlation between the total neutrino energy (TONE) and the cumulative number of neutrino events in each detector, a correlation that can facilitate data analyses of real observations. We demonstrate the retrieval of neutrino energy spectra for all flavours of neutrino by applying a novel spectrum reconstruction technique to the data from multiple detectors. We find that this new method is capable of estimating the TONE within the error of ∼20 per cent if the distance to the CCSN is ≲6 kpc.

Constraining sterile neutrinos by core-collapse supernovae with multiple detectors

The eV-scale sterile neutrino has been proposed to explain some anomalous results in experiments, such as the deficit of reactor neutrino fluxes and the excess of ν̄μ→ν̄e in LSND. This hypothesis can be tested by future core-collapse supernova neutrino detection independently since the active-sterile mixing scheme affects the flavor conversion of neutrinos inside the supernova. In this work, we compute the predicted supernova neutrino events in future detectors—DUNE, Hyper-K, and JUNO—for neutrinos emitted during the neutronization burst phase when the luminosity of νe dominates the other flavors. We find that for a supernova occurring within 10 kpc, the difference in the event numbers with and without sterile neutrinos allows to exclude the sterile neutrino hypothesis at more than 99% confidence level robustly. The derived constraints on sterile neutrinos mixing parameters are comparably better than the results from cosmology and on-going or proposed reactor experiments by more than two orders of magnitude in the sin22θ14–Δ m412 plane.

Theoretical Prediction of Presupernova Neutrinos and Their Detection

More than 30 years have passed since the successful detection of supernova (SN) neutrinos from SN 1987A. In the last few decades, remarkable progress has been made in neutrino detection techniques, through which it may be possible to detect neutrinos from a new source, presupernova (pre-SN) neutrinos. They are emitted from a massive star prior to core bounce. Because neutrinos escape from the core freely, they carry information about the stellar physics directly. Pre-SN neutrinos may play an important role in verifying our understanding of stellar evolution for massive stars. Observation of pre-SN neutrinos, moreover, may serve as an alarm regarding an SN explosion a few days in advance if the progenitor is located in our vicinity, enabling us to observe the next galactic SN. In this review, we summarize the current status of pre-SN neutrino studies from both the theoretical and observational points of view.

Neutrino Emission as Diagnostics of Core-Collapse Supernovae

With myriads of detection events from a prospective Galactic core-collapse supernova, current and future neutrino detectors will be able to sample detailed, time-dependent neutrino fluxes and spectra. This will offer significant possibilities of inferring supernova physics from the various phases of the neutrino signal, ranging from the neutronization burst through the accretion and early explosion phases to the cooling phase. The signal will constrain the time evolution of bulk parameters of the young proto–neutron star, such as its mass and radius, as well as the structure of the progenitor; probe multidimensional phenomena in the supernova core; and constrain the dynamics of the early explosion phase. Aside from further astrophysical implications, supernova neutrinos may also shed light on the properties of matter at supranuclear densities and on open problems in particle physics.