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the interaction of electron neutrino flux, originating in the rotational collapse mechanism on the first stage of supernova burst, with the lsd detector components, such as 56fe (a large amount of this metal is included in as shielding material) and liquid scintillator barnnh2n+2, is being investigated. both charged and neutral channels of neutrino reaction with 12barn and 56fe are considered. experimental data, giving the possibility to extract information for nuclear matrix elements calculation are used. the number of signals, produced in lsd by the neutrino pulse of supernova 1987a is determined. the obtained results are in good agreement with experimental data. | interaction of electron neutrino with lsd detector |
the nozières-pines method for describing neutron scattering on a heated fermi liquid (liquid 3he) is used to calculate cross sections for inelastic neutrino scattering on the isotope 54fe, which is an element that plays a key role in the cooling of supernovae. the calculation in question is performed on the basis of the the theory of finite fermi systems with the aid of the df3-a fayans energy density functional. | inelastic neutrino scattering on hot nuclei of supernova matter within the theory of finite fermi systems |
icecube has proven that its low background environment allows for the detection of mev neutrinos from core-collapse supernovae (sne). these neutrinos can reveal the time structure of the evolution of a sn and enhance our picture of these explosions. however, icecube is not able to reconstruct such neutrinos individually but they are measured as a collective enhancement of the modules dominating dark rate, which limits the distance at which sne can be detected. for the design of new icecube extensions, new modules like the multi-pmt optical module (mdom) are being developed which are expected to significantly increase the detector sensitivity. featuring local coincidences and directional information on detected photons, the mdom may allow for event-by-event detection of mev neutrinos with a single module. the poster presents initial studies concerning the detection efficiency of mdoms for mev neutrinos and the potential of a detector instrumented with mdoms to detect extragalactic sne. | sensitivity of multi-pmt optical modules to mev supernova neutrinos in south pole ice |
an influence of a magnetic field on beta-processes is investigated under conditions of a core-collapse supernova. for realistic magnetic fields reachable in astrophysical objects we obtain simple analytical expressions for reaction rates of beta-processes as well as the energy and momentum transferred from neutrinos and antineutrinos to the matter. based on the results of one-dimensional simulations of a supernova explosion, we found that, in the magnetic field with the strength b ∼1015 g , the quantities considered are modified by a few percents only and, as a consequence, the magnetic-field effects can be safely neglected, considering neutrino interaction and propagation in a supernova matter. the analytical results can be also applied for accretion discs formed at a merger of compact objects in close binary systems. | influence of a magnetic field on beta-processes in supernova matter |
we study the impact of the nucleon-α p -wave resonances on neutrino-pair bremsstrahlung. because of the noncentral spin-orbit interaction, these resonances lead to an enhanced contribution to the nucleon spin structure factor for temperatures t ≲4 mev. if the α -particle fraction is significant and the temperature is in this range, this contribution is competitive with neutron-neutron bremsstrahlung. this may be relevant for neutrino production in core-collapse supernovae or other dense astrophysical environments. similar enhancements are expected for resonant noncentral nucleon-nucleus interactions. | neutrino-pair bremsstrahlung from nucleon-α versus nucleon-nucleon scattering |
when a supernova explodes, most of its energy is released in a shell of relativistic neutirnos which changes the surrounding geometry. we calculate the potentially observable responses to such a change in both pulsar scintillation and conventional interferometers. in both cases, the responses are permanent changes due to such a transient event. this is by-definition a memory effect. in addition to the transverse component in the usual gravitational memory (christodolou effect) effect, it also has a longitudinal component. furthermore it is different from the christodolou effect as the transverse component of this memory effect also has a term that grows with time. | memory effect from supernova neutrino shells |
we review our recent calculations of neutrino-antineutrino pair production from bremsstrahlung processes in hadronic collisions at temperature and densities relevant for core-collapse supernovae. we focus on neutron-neutron and neutron-α collisions. | emission of neutrino-antineutrino pairs by hadronic bremsstrahlung processes |
we have explored the impact of sterile neutrino dark matter on core-collapse supernova explosions. we have included oscillations between electron neutrinos or mixed $\mu,\tau$ neutrinos and right-handed sterile neutrinos into a supernova model. we have chosen sterile neutrino masses and mixing angles that are consistent with sterile neutrino dark matter candidates as indicated by recent x-ray flux measurements. using these simulations, we have explored the impact of sterile neutrinos on the core bounce and shock reheating. we find that, for ranges of sterile neutrino mass and mixing angle consistent with most dark matter constraints, the shock energy can be significantly enhanced and even a model that does not explode can be made to explode. in addition, we have found that the presence of a sterile neutrino may lead to detectable changes in the observed neutrino luminosities. | sterile neutrino dark matter and core-collapse supernovae |
we show that future observations of binary neutron star systems with electromagnetic counterparts together with the traditional probes of low- and high-redshift type ia supernovae (sne ia) can help resolve the hubble tension. the luminosity distance inferred from these probes and its scatter depend on the underlying cosmology. by using the gravitational lensing of light or gravitational waves emitted by, and peculiar motion of, these systems we derive constraints on the sum of neutrino masses, the equation of state of dark energy parameterized in the form ${w}_{0}+{w}_{a}(1-a)$ , along with the hubble constant and cold dark matter density in the universe. we show that even after marginalizing over poorly constrained physical quantities, such as the sum of neutrino masses and the nature of dark energy, low-redshift gravitational-wave observations, in combination with sne ia, have the potential to rule out new physics as the underlying cause of the hubble tension at ≳5.5σ. | standard candles and sirens rescue h0 |
in this work the supernova neutrino (sn) charged-current interactions with gd odd isotopes (a=155 and 157) are studied. we use measured spectra and the quasiparticle-phonon model (mqpm) to calculate the charged current response of odd gd isotopes to supernova neutrinos. flux-averaged cross sections are obtained considering quasi-thermal neutrino spectra. | supernova neutrino scattering off gadolinium odd isotopes in water cherenkov detectors |
in recent years we started feasibility studies for joint search for gravitational waves (gws) and neutrinos from core collapse supernovae (sn) involving members of the gw and neutrino communities. this collaborative work is aimed to maximize the science out of the existing and forthcoming instruments as they monitor the nearby universe for core-collapse sn. a first paper on this has appeared in ref.1, an update of which is under way. the present work captures the current status of this effort and key questions that have steered the discussion and work since then... | joint search for gravitational waves and neutrinos from core-collapse supernovae |
super-kamiokande (sk) will start a new phase “sk-gd” from next year. currently, sk uses geant3 based simulation, however, its development has already stopped. for the next 10 years of sk-gd operation, updated detector simulation is essential. for diffuse supernova neutrino background search in sk-gd, precise neutron simulation is crucial. therefore, we developed geant4 based sk simulation software, named’ skg4’ . starting from the construction of sk geometry, some comparisons with the current sk detector simulation has been done. in this presentation, the current status of the development for skg4 and the result of the several physics simulations will be reported. | geant4 based simulation study for super-kamiokande |
type ii sne, also called core-collapse supernovae have a neutrino (v) emission, as confirmed by sn 1987a, and are also potential sources of gravitational waves. neutrinos and gravitational waves from these sources reach earth almost contemporaneously and without relevant interaction with stellar matter and interstellar medium. the upcoming advanced gravitational interferometers would be sensitive enough to detect gravitational waves signals from close galactic core-collapse supernovae events. nevertheless, significant uncertainties on theoretical models of emission remain. a joint search of coincident low energy neutrinos and gravitational waves events from these sources would bring valuable information from the inner core of the collapsing star and would enhance the detection of the so-called silent supernovae. recently a project for a joint search involving gravitational wave interferometers and neutrino detectors has started. we discuss the benefits of a joint search and the status of the search project. | methodological studies on the search for gravitational waves and neutrinos from type ii supernovae |
the deep underground neutrino experiment (dune) experiment, a 40-kton underground liquid argon time-projection-chamber detector, will have unique sensitivity to the electron flavor component of a core-collapse supernova neutrino burst. we present the expected capabilities of dune for measurements of neutrinos in the few-tens-of-mev range relevant for supernova detection and its corresponding sensitivity to both neutrino physics and supernova astrophysics. recent progress and some outstanding issues are highlighted. | supernova neutrinos at the dune experiment |
in this work an astrophysical simulation code, xflat, is developed to study neutrino oscillations in supernovae. xflat is a hybrid modular code which was designed to utilize multiple levels of parallelism through mpi, openmp, and simd instructions (vectorization). it can run on both the cpu and the xeon phi co-processor, the latter of which is based on the intel many integrated core architecture (mic). the performance of xflat on various system configurations and physics scenarios has been analyzed. in addition, the impact of i/o and the multi-node configuration on the xeon phi-equipped heterogeneous supercomputers such as stampede at the texas advanced computing center (tacc) was investigated. | simulating nonlinear neutrino oscillations on next-generation many-core architectures |
as per simulation studies, the weak reaction rates on nickel isotopes play a substantial role in affecting the ratio of electron-to-baryon content of stellar interior during the late stages of core evolution. (anti)neutrinos are produced in weak-decay processes, and escape from the stellar content having densities less than 1011 g cm-3. they take away energy and reduce the stellar core entropy. in this paper we report on the microscopic calculation of neutrino and antineutrino cooling rates due to weak rates on nickel isotopes in mass range 56 ≤ a ≤ 71. the calculations are accomplished by employing the deformed pn-qrpa model. recent studies on gt strength properties of nickel isotopes show that the deformed pn-qrpa model well explained the experimental charge-changing transitions. our calculated beta decay half-lives for selected nickel isotopes are in excellent comparison with experimental data. the (anti)neutrino cooling rates are determined over temperatures in the range of 0.01 × 109 - 30 × 109 k and densities in the range of 10 - 1011 g cm-3 domain. the computed rates are compared with previous theoretical calculations. for neutron rich nuclide, at high temperatures, our computed cooling rates are enhanced as compared to previous calculations. | neutrino cooling rates due to nickel isotopes for presupernova evolution of massive stars |
we present initial results from three-dimensional simulations of parametrized core-collapse supernova (ccsn) explosions obtained with our astrophysical simulation code general astrophysical simulation system (genasis). we are interested in nonlinear flows resulting from neutrino-driven convection and the standing accretion shock instability (sasi) in the ccsn environment prior to and during the explosion. by varying parameters in our model that control neutrino heating and shock dissociation, our simulations result in convection-dominated and sasi-dominated evolution. we describe this initial set of simulation results in some detail. to characterize the turbulent flows in the simulations, we compute and compare velocity power spectra from convection-dominated and sasi-dominated (both non-exploding and exploding) models. when compared to sasi-dominated models, convection-dominated models exhibit significantly more power on small spatial scales. | convection- and sasi-driven flows in parametrized models of core-collapse supernova explosions |
gamma ray heating and neutrino cooling rates, due to weak interaction processes, on sd-shell nuclei in stellar core are calculated using the proton neutron quasiparticle random phase approximation theory. the recent extensive experimental mass compilation of wang et al. (chin. phys. c 36:1603, 2012), other improved model input parameters including nuclear quadrupole deformation (raman et al. in at. data nucl. data tables 78(1):1-128, 2001; möller et al. in at. data nucl. data tables 109:1-204, 2016) and physical constants are taken into account in the current calculation. the purpose of this work is two fold, one is to improve the earlier calculation of weak rates performed by nabi and klapdor-kleingrothaus (at. data nucl. data tables 71:149, 1999a) using the same theory. we further compare our results with previous calculations. the selected sd-shell nuclei, considered in this work, are of special interest for the evolution of o-ne-mg core in 8-10 m_{⊙} stars due to competitive gamma ray heating rates and cooling by urca processes. the outcome of these competitions is to determine, whether the stars end up as a white dwarf (nabi in phys. rev. c 78(4):045801, 2008b), an electron-capture supernova (jones et al. in astrophys. j. 772(2):150, 2013) or fe core-collapse supernova (suzuki et al. in astrophys. j. 817(2):163, 2016). the selected sd-shell nuclei for calculation of associated weak-interaction rates include ^{20,23}o, ^{20,23}f, ^{20,23,24}ne, {}^{20,23-25}na, and {}^{23-25}mg. the cooling and heating rates are calculated for density range (10 ≤ ρ (g cm^{-3}) ≤ 10^{11}) and temperature range (0.01× 109≤ t(k)≤ 30× 109). the calculated gamma heating rates are orders of magnitude bigger than the shell model rates (except for ^{25}mg at low densities). at high temperatures the gamma heating rates are in reasonable agreement. the calculated cooling rates are up to an order of magnitude bigger for odd-a nuclei. | gamma ray heating and neutrino cooling rates due to weak interaction processes on sd-shell nuclei in stellar cores |
this paper is a sequel to takahashi et al., in which the authors investigated the influences of fluctuations in preshock accreting matter on the linear stability of the standing accretion shock in core-collapse supernovae (ccsne). if one understands that this was concerning the effect of the outer boundary condition for the postshock accretion flows, the present paper should be regarded as an investigation of the possible influences of the inner boundary conditions. more specifically, we impose a time-dependent, oscillating condition at the inner boundary, having in mind the injection of acoustic power by an oscillating proto-neutron star. we also consider possible correlations between the inner and outer boundary conditions as invoked in the argument for lepton-number emission self-sustained asymmetry (lesa). in this paper, we conduct the linear stability analysis of the standing accretion shock commonly encountered in ccsne on the basis of laplace transform. we find that the acoustic power enhances the standing accretion shock instability (sasi), especially when the luminosity is low. on the other hand, the correlation between the fluctuations of neutrino luminosity at the neutrino sphere has little influence on the instability, changing the amplitudes of eigenmodes only slightly. we further investigate steady solution of perturbation equations, being motivated by lesa, and conclude that not the difference but the sum of the fluxes of νeand {\bar{ν }}e is the key ingredient to production of the self-sustained steady perturbed configuration. | linear analysis of the shock instability in core-collapse supernovae: influences of acoustic power and fluctuations of neutrino luminosity |
we have developed the astrophysical simulation code xflat to study neutrino oscillations in supernovae. xflat is designed to utilize multiple levels of parallelism through mpi, openmp, and simd instructions (vectorization). it can run on both cpu and xeon phi co-processors based on the intel many integrated core architecture (mic). we analyze the performance of xflat on configurations with cpu only, xeon phi only and both cpu and xeon phi. we also investigate the impact of i/o and the multi-node performance of xflat on the xeon phi-equipped stampede supercomputer at the texas advanced computing center (tacc). | performance analysis of an astrophysical simulation code on the intel xeon phi architecture |
a quantitative understanding of neutrino-nucleus interactions is demanded to achieve precise measurement of neutrino oscillations, and hence the determination of their masses. in addition, next generation detectors will be able to detect supernovae neutrinos, which are likely to shed some light on the open questions on the dynamics of core collapse. in this context, it is crucial to account for two-body meson-exchange currents along within realistic models of nuclear dynamics. we summarize our progresses towards the construction of a consistent framework, based on the green's function monte carlo method, that can be exploited to accurately describe neutrino interactions with atomic nuclei in the quasi-elastic sector. | green's function monte carlo calculations of the electromagnetic and neutral-weak response functions in the quasi-elastic sector |
a massive neutrino has nonzero magnetic moment and is involved in the electromagnetic interactions with external fields and photons. the electromagnetic neutrino moving in matter can emit the spin light (slν) in the process of transition between two quantum states in matter. in quite resembling way an electron can emit spin light in moving background composed of neutrinos, that is “the spin light of an electron in neutrino flux” (sleν). in this paper we obtain the exact solution for the wave function and energy spectrum for an electron moving in a neutrino flux and consider the sleν as the transition process between two electron quantum states in the background. the sleν radiation rate, power and emitted photon energy are calculated. notably, the energy spectrum of the emitted sleν photons can span up to gamma-rays. we argue that the considered sleν can be of interest for astrophysical applications, for supernovae processes in particular. | from electromagnetic neutrinos to new electromagnetic radiation mechanism in neutrino fluxes |
the results of the time coincidences of rare events in the lvd and bust detectors are presented. the rare events could be caused by neutrino interaction in the experimental setup. the distributions of the coincidence number per day for 4-year period are obtained. | the search for coincidences of rare events using lvd and bust detectors |
first the neutrinos arrived, then the burst of light: messengers of a cataclysmic event in the galaxy next door. alak ray recounts iaus 331, a conference that celebrated the thirtieth anniversary of the supernova of a lifetime, sn1987a, and explored the critical role of asymmetry in the explosions, surroundings and initial conditions. | iaus 331: supernova 1987a thirty years later |
abstract not available. | neutrinos in core-collapse supernovae |
this talk will briefly survey the capabilities of current detectors sensitive to supernova neutrino bursts. it will then cover recent progess in development of supernova neutrino detection techniques as well as prospects for specific future experiments. | supernova neutrino detection |
neutron stars are important because measurement of their masses and radii will determine the dense matter equation of state. they will constrain the nuclear matter symmetry energy, which controls the neutron star matter pressure and the interior composition, and will influence the interpretation of nuclear experiments. astrophysical observations include pulsar timing, x-ray bursts, quiescent low-mass x-ray binaries, pulse profiles from millisecond pulsars, neutrino observations from gravitational collapse supernovae,and gravitational radiation from compact object mergers. these observations will also constrain the neutron star interior, including the properties of superfluidity there, and determine the existence of a possible qcd phase transition. | neutron star physics and eos |
we present results from an ab initio three-dimensional, multi-physics core collapse supernova simulation for the case of a 15 m⊙ progenitor. our simulation includes multi-frequency neutrino transport with state-of-the-art neutrino interactions in the “ray-by-ray” approximation, and approximate general relativity. our model exhibits a neutrino-driven explosion. the shock radius begins an outward trajectory at approximately 275 ms after bounce, giving the first indication of a developing explosion in the model. the onset of this shock expansion is delayed relative to our two-dimensional counterpart model, which begins at approximately 200 ms after core bounce. at a time of 441 ms after bounce, the angle-averaged shock radius in our three-dimensional model has reached 751 km. further quantitative analysis of the outcomes in this model must await further development of the post-bounce dynamics and a simulation that will extend well beyond 1 s after stellar core bounce, based on the results for the same progenitor in the context of our two-dimensional, counterpart model. this more complete analysis will determine whether or not the explosion is robust and whether or not observables such as the explosion energy, 56ni mass, etc. are in agreement with observations. nonetheless, the onset of explosion in our ab initio three-dimensional multi-physics model with multifrequency neutrino transport and general relativity is encouraging. | a three-dimensional neutrino-driven core collapse supernova explosion of a 15 m⊙ star |
hyper-kamiokande (hk), a proposed one-megaton water cherenkov detector to be built in japan, is the logical continuation of the highly successful program of neutrino (astro)physics and proton decay using the water cherenkov technique. hk will search for cp violation in neutrino oscillations associated with the irreducible phase δ in the lepton mixing matrix using the neutrino beam produced at j-parc. with an exposure of 7.5 mw × 107sec, δ can be measured to better than 19 degrees at all values, and cp violation can be detected with more than 3 σ significance for 76% of values of delta. in addition to the search for neutrino cp violation, hk will offer a broad program of neutrino astrophysics, including continued studies of atmospheric neutrinos and the detection of neutrinos produced in supernovae as far as the andromeda galaxy. it will also extend the sensitivity to proton decay, an incontrovertible sign of new physics and grand unification, by an order of magnitude. | hyper-kamiokande: a next generation neutrino observatory to search for cp violation in the lepton sector |
we show that when a supernova explodes, a nearby pulsar signal goes through a very specific change. the observed period first changes smoothly, then is followed by a sudden change in the time derivative. a stable millisecond pulsar can allow us to measure such an effect. this may improve our measurement of the total energy released in neutrinos and also the orientation of the supernova-pulsar system. | pulsar acceleration shifts from nearby supernova explosion |
recent work has suggested that the chirality of the amino acids could be established in the magnetic field of a nascent neutron star from a core-collapse supernova via processing by the neutrinos that would be emitted. a model is described that can be used to estimate the bulk polarization of large rotating meteoroids in the magnetic field of a neutron star. this model assumes that the neutrinos emitted from the nascent neutron star would interact with the amino acids, which had been oriented by the neutron star's magnetic field. the results of this model are applicable to the supernova neutrino amino acid processing model, which describes one possible way in which the amino acids, known in many cases to exhibit supramolecular chirality, could have become enantiomeric. we have studied the capability of this model for selective destruction of one molecular chirality. although some aspects of the model are speculative, tests may be possible to at least check the capability of this most basic aspect of the model. | determining amino acid chirality in the supernova neutrino processing model |
in understanding the origin of the heavy elements, the "light heavy elements" pose a particular challenge: the two neutron-capture processes, r- and s-process, cannot explain the abundances patterns seen in very old galactic halo stars. a proposed solution to this problem is the ν p-process, which takes place in the strong neutrino-driven winds of core-collapse supernovae. in the ν p-process, a sequence of (n, p) and (p, γ ) reactions allows for the synthesis of elements with atomic numbers a > 64, which includes sr, y, zr, and others possibly up to sn. the relevant reaction rates are all based on statistical model predictions and carry some uncertainty. here, the sensitivity of the final ν p-process abundance pattern on modifications of (n, p), (p, γ ), and (n, γ ) reactions are characterized. only few reactions affect the final abundance pattern and hence warrant a more detailed study of the reaction rate. | nuclear reactions and the ν p-process |
known models proposed to explain the high space velocities of pulsars based on asymmetry of the transport coefficients of different sorts of neutrinos or electromagnetic radiation can be efficient only in the presence of high magnetic fields (to 1016 g) or short rotation periods for the neutron stars (of the order of 1 ms). this current study shows that the observed velocities are not correlated with either the pulsar periods or their surface magnetic fields. the initial rotation periods are estimated in a model for the magnetedipolar deceleration of their spin, aßsuming that the pulsar ages are equal to their kinematic ages. the initial period distribution is bimodal, with peaks at 5 ms and 0.5 s, and similar to the current distribution of periods. it is shown that asymmetry of the pulsar electromagnetic radiation is insufficient to give rise to additional acceleration of pulsars during their evolution after the supernova explosion that gave birth to them. the observations testify to deceleration of the motion, most likely due to the influence of the interstellar medium and interactions with nearby objects. the time scale for the exponential decrease in the magnetic field τdand in the angle between the rotation axis and magnetic moment τßare estimated, yielding τβ= 1.4 million years. the derived dependence of the transverse velocity of a pulsar on the angle between the line of sight and the rotation axis of the neutron star corresponds to the expected dependence for acceleration mechanisms associated with asymmetry of the radiation emitted by the two poles of the star. | the space velocities of radio pulsars |
core-collapse supernovae (ccsne) have a neutrino (v) signature confirmed by sn 1987a and are potential sources of gravitational waves (gws). vs and gws coming from these sources will reach the observer almost simultaneously and without significant interaction with interstellar matter. the expected gw signals are in the range of the upcoming advanced detectors for galactic neighborhood events. however, there are still significant uncertainties on the theoretical model of the emission. a joint search of coincident vs and gws from these sources would bring valuable information from the inner core of the collapsing star and would enhance the detection of the so-called silent supernovae. recently, a project for a joint search involving gw interferometers and v detectors has started. in this paper we discuss about the principal gw theoretical models of emission, and we present a methodological study of the joint search project between gw and v. | methodology of the joint search for gravitational wave and low energy neutrino signals from core-collapse supernovae |
within a few tens of seconds after infall, a core-collapse supernova radiates the vast majority of the binding energy of the resulting compact remnant in the form of neutrinos of all flavors. while the calculation of the number of neutrinos can be performed at different levels of sophistication, we outline an estimate that highlights the direct connection between the number of neutrinos and their detected energy to the basic properties of the supernova and its temporal evolution. information about the astrophysics of the collapse and subsequent explosion, and about the physics of neutrinos, is encoded in the time, energy, and flavor structure of the neutrino burst. the next supernova neutrino burst in the milky way or nearby will be observable in a number of large neutrino detectors around the world; planned new and larger detectors will enhance the sensitivity further. this article describes the neutrino burst signal expected from a core-collapse supernova and what we will learn from it, including the early alert for core collapse. it will describe different types of neutrino detectors with supernova neutrino sensitivity and the capabilities of current and future neutrino detectors worldwide. in a concluding section, we discuss how, after thousands of years, the supernova remnant transforms itself into a particle accelerator that emits observable fluxes of neutrino of tev energy. | neutrinos from core-collapse supernovae and their detection |
the nuclear equation-of-state (eos) describing newly formed proto-neutron stars (pnss) in core-collapse supernovae (ccsne) is yet uncertain, and varying its prescription affects multimessenger signatures in ccsn simulations. focusing on the gravitational wave (gw) signal, we demonstrate the effect of varying parameter values in the eos. we conclude that an especially important parameter is the effective mass of nucleons which affect thermal properties and subsequently the pns compactness, regulating the gw signal in both amplitude and frequency. by radially decomposing the gw emission, we show where in the pns the gws originate from. | equation-of-state effects on gravitational waves in core-collapse supernovae |
in addition to 18000 20-inch large pmts (lpmts), the juno experiment will use 25000 3-inch small photomultiplier tubes (spmts) to help control the non-stochastic term of the energy resolution and to improve the reconstruction of cosmic-ray muons and supernova burst neutrino events, among other benefits. the 3-inch pmts are required to have good resolution for single photoelectrons, high quantum efficiency, good transit time spread and low dark rate. production of custom-designed 3-inch pmts is now in progress at hainan zhanchuang photonics technology co. (hzc photonics). this poster will provide an overview of the design, status and performance testing of the 3-inch pmts of juno. | the 3-inch pmts of the juno experiment |
this talk will review the microphysics components essential to the modeling of compact object mergers (binary neutron stars and neutron star-black holes) as well as the birth place of neutron stars, core-collapse supernovae. i will begin with core-collapse supernovae. for these systems, the microphysics modeling has arguably matured to a level where basic consequences of the microphysics such as the baseline neutrino signal and black hole formation properties of failed supernovae are accurately reproducible by independent modelers. however, there are still many areas of core-collapse supernova modeling that are less established. this is especially true in multidimensional simulations, which are accompanied by many fluid instabilities. there is still not consensus between modelers on the explosion outcome (i.e. success or failure) of core collapse, and in cases where there is agreement on the outcome, the explosion properties (e.g. energy, explosion time, ...) are often disparate. i will briefly review the current status of state-of-the-art, multidimensional, computational models of core-collapse supernovae. for binary neutron star and neutron-star black hole mergers on the other hand, only recently are there simulations that use full general relativity and incorporate neutrino and nuclear microphysics in earnest. this has lead to higher fidelity predictions of the ejected material and its composition, the accretion disk formation and early evolution, and the gravitational wave signal and its dependence on the nuclear equation of state, and the neutrino signal. i will also review these microphysical aspects. | microphysical aspects of supernova and compact object merger modeling |
a massive neutrino has nonzero magnetic moment and is involved in the electromagnetic interactions with external fields and photons. the electromagnetic neutrino moving in matter can emit the spin light (slν) in the process of transition between two quantum states in matter. in quite resembling way an electron can emit spin light in moving background composed of neutrinos, that is "the spin light of an electron in neutrino flux" (sleν). in this paper we obtain the exact solution for the wave function and energy spectrum for an electron moving in a neutrino flux and consider the sleν as the transition process between two electron quantum states in the background. the sleν radiation rate, power and emitted photon energy are calculated. notably, the energy spectrum of the emitted sleν photons can span up to gamma-rays. we argue that the considered sleν can be of interest for astrophysical applications, for supernovae processes in particular. | from electromagnetic neutrinos to new electromagnetic radiation mechanism in neutrino fluxes |
we present an initial report on 160 simulations of a highly simplified model of the post-bounce core-collapse supernova environment in three spatial dimensions (3d). we set different values of a parameter characterizing the impact of nuclear dissociation at the stalled shock in order to regulate the post-shock fluid velocity, thereby determining the relative importance of convection and the stationary accretion shock instability (sasi). while our convection-dominated runs comport with the paradigmatic notion of a `critical neutrino luminosity' for explosion at a given mass accretion rate (albeit with a nontrivial spread in explosion times just above threshold), the outcomes of our sasi-dominated runs are much more stochastic: a sharp threshold critical luminosity is `smeared out' into a rising probability of explosion over a ~ 20 % range of luminosity. we also find that the sasi-dominated models are able to explode with 3 to 4 times less efficient neutrino heating, indicating that progenitor properties, and fluid and neutrino microphysics, conducive to the sasi would make the neutrino-driven explosion mechanism more robust. | stochasticity and efficiency of convection-dominated vs. sasi-dominated supernova explosions |
neutrino driven convection is an essential process in reviving the stalled shock in core-collapse supernovae. we analyze the convective properties of a 15 m⊙ core-collapse supernova in 3d at 3 different spatial resolutions simulated using the neutrino radiation hydrodynamics code chimera. we seek to understand the impact of spatial resolution on neutrino-driven convection in the gain region before the shock is revived. we examine the relationship between spatial resolution and convective energy transport properties such as convective flux, kinetic flux, buoyant work, and expansion work at various times during the shock revival period. we compare and contrast the convection profiles generated with those produced by other codes with different neutrino transport schemes. | neutrino driven convection in 15 m⊙ supernova models at different spatial resolutions |
first three-dimensional, first-principle simulations of core-collapse supernovae have become possible in the recent past. they demonstrate the basic viability of the neutrino-driven mechanism for powering the explosions of the majority of supernova progenitors. although a number of open questions remain to be settled, the explosion models are now sufficiently mature to strive for detailed comparisons against observations, for example considering well studied, nearby supernovae and young supernova remnants. this talk will review our basic understanding of the explosion mechanism and report some results of such observational tests. | 3d core-collapse supernova modeling and applications to cas a and other supernova remnants |
this version of snewpy was submitted to the journal of open source software (see pre-review and review). many thanks to the reviewers and editors! what's changed since v1.0 added multiple new models (zha_2021, fornax_2019, fornax_2021, tamborra_2014, tamborra_2014, walk_2018, walk_2019) added new togashi eos simulation to nakazato_2013 model easier interface to download available sn model files redesigned snowglobes interface (snewpy.snowglobes module) snewpy is now available on pypi via pip install snewpy added documentation on read the docs, improved example notebooks and scripts various minor bugfixes, performance and other improvements snewpy now requires python 3.7 or newer. new contributors @joshuashzha made their first contribution in https://github.com/snews2/snewpy/pull/35 @schol made their first contribution in https://github.com/snews2/snewpy/pull/39 @thomahrens made their first contribution in https://github.com/snews2/snewpy/pull/41 @mcolomermolla made their first contribution in https://github.com/snews2/snewpy/pull/56 @jpkneller made their first contribution in https://github.com/snews2/snewpy/pull/93 @sgriswol made their first contribution in https://github.com/snews2/snewpy/pull/105 full changelog: https://github.com/snews2/snewpy/compare/v1.0.0...v1.1 | snewpy: a data pipeline from supernova simulations to neutrino signals |
in the version of this article originally published the fig. 6 y axis label read 'mej' but should have read 'mni'. this has now been corrected. | publisher correction: hydrogen-rich supernovae beyond the neutrino-driven core-collapse paradigm |
proton rich neutrino driven winds in core-collapse supernovae can be a suitable environment for the formation of elements up to z 50 via the so called neutrino-p (νp-)process. the strength of νp-process depends on key (n,p) reactions like the 56ni(n,p)56coand64ge(n,p)64ga for which no experimental data exists. with the current state of the art any direct measurement of (n,p) reactions on neutron deficient nuclei is extremely challenging. for this purpose, a new experimental technique has been developed in the rea3 facility at national superconducting cyclotron laboratory for the study of astrophysical important (n,p) reactions via measuring the time reverse (p,n) reactions. in this presentation, a description of the technique and results from the first proof-of-principle run will be shown. us department of energy: office of science. | a new experimental technique for measuring (p,n) reactions relevant to the neutrino-p process in the rea3 facility |
galactic supernovae are rare, just a few per century, so it is important to be prepared. if we are, then the long-baseline detector dune could detect thousands of events, compared to the tens from sn 1987a. an important question is backgrounds from muon-induced spallation reactions. we simulate particle energy-loss processes in liquid argon, and compare relevant isotope yields with those in the water-cherenkov detector superk. our approach will help optimize the design of dune and further benefit the study of supernova neutrinos. gz, swl, and jfb are supported by nsf phy-1714479. | muon-induced spallation backgrounds in dune |
supernova explosions are inherently asymmetric and can accelerate new-born neutron stars (nss) to hundreds of km/s. two prevailing theories to explain ns kicks are ejecta asymmetries (e.g., conservation of momentum between ns and ejecta) and anisotropic neutrino emission. observations of supernova remnants (snrs) can give us insights into the mechanism that generates these ns kicks. in this presentation, we investigate the relationship between ns kick velocities and the x-ray morphologies of 18 snrs observed with chandra and rosat. we measure snr asymmetries using the power-ratio method (a multipole expansion technique), focusing on the dipole, quadrupole, and octupole power-ratios. our results show no correlation between the magnitude of the power-ratios and ns kick velocities, but we find that for cas a and g292.0+1.8, whose emission traces the ejecta distribution, their nss are preferentially moving opposite to the bulk of the x-ray emission. in addition, we find a similar result for pks 1209-51, ctb 109, and puppis a; however their emission is dominated by circumstellar/interstellar material, so their asymmetries may not reflect their ejecta distributions. our results are consistent with the theory that ns kicks are a consequence of ejecta asymmetries as opposed to anisotropic neutrino emission. in the future, additional observations to measure ns proper motions within ejecta-dominated snrs are necessary to constrain robustly the ns kick mechanism. | comparing neutron star kicks to supernova remnant asymmetries |
liquid argon time projection chambers (lartpcs) have been proposed as neutrino detectors that combine both large sizes to maximize the number of neutrino interactions and detailed recording of the interaction. the readout of thousands of channels at mhz sampling rates produce images of the neutrino-nucleus interaction with millimeter-scale resolution, enabling the identification of the resulting particles and offering multiple handles to measure their energies at the expense of large data rates. continuous acquisition of the lartpc data is required to enable the use of high-latency triggers for capturing non-accelerator-beam events. we describe the case of the continuous readout of the microboone lartpc, that grants the possibility of acquiring the neutrino burst from a supernova using the snews (supernova early warning system) alert as delayed trigger. the continuous data acquisition is accomplished by using real-time compression algorithms (zero suppression and huffman compression) implemented in an fpga in the readout electronics. | continuous data acquisition for liquid argon time projection chamber neutrino detectors using fpga-based real-time compression algorithms |
following our paper [1], we study the effects of nonzero dirac and majorana cp violating phases on neutrino-antineutrino oscillations engendered by magnetic fields of astrophysical environments. we show that in the presence of strong magnetic fields and dense matter, nonzero cp phases can induce new resonances in neutrino-antineutrino oscillations, in particular in the channels ${\nu }_{e}\leftrightarrow {\bar{\nu }}_{e},\,{\nu }_{e}\leftrightarrow {\bar{\nu }}_{\mu }$ and ${\nu }_{e}\leftrightarrow {\bar{\nu }}_{\tau }$ . the discovered resonances can lead to appearance of potentially observable phenomena in neutrino oscillations accessible for observation in future experiments, such as juno and hyper-kamiokande. | effects of nonzero majorana cp phases on oscillations of supernova neutrinos |
core-collapse supernovae are some of the most energetic events in the modern universe. they are powered by the release of gravitational binding energy that occurs when the iron core of a massive star collapses into a neutron star. by far, the majority of the energy released is radiated in neutrinos. since these neutrinos travel unimpeded through the mantle of the massive star, they are one of the best ways to observationally probe the inner workings of core-collapse supernovae. in this presentation, i will discuss predictions of neutrino emission from core-collapse supernova simulations and describe what its detection in earth-based detectors can tell us about massive star evolution and the properties of the central engine of core-collapse supernovae. | neutrino emission from core-collapse supernovae |
we investigate the quark deconfinement phase transition in cold (t = 0) and hot β-stable hadronic matter. assuming a first-order phase transition, we calculate and compare the nucleation rate and the nucleation time due to quantum and thermal nucleation mechanisms. we show that above a threshold value of the central pressure a pure hadronic star (hs) (i.e. a compact star with no fraction of deconfined quark matter (qm)) is metastable to the conversion to a quark star (qs) (i.e. a hybrid star or a strange star). this process liberates a huge amount of energy, of the order of 1053 erg, which produces a powerful neutrino burst, likely accompanied by intense gravitational waves emission, and possibly by a second delayed (with respect to the supernova explosion forming the hs) explosion which could be the energy source of a powerful gamma-ray burst (grb). this stellar conversion process populates the qs branch of compact stars, thus one has in the universe two coexisting families of compact stars: hss and qss. we introduce the concept of critical mass mcr for cold hss and proto-hadronic stars (phss), and the concept of limiting conversion temperature for phss. we show that phss with a mass m < mcr could survive the early stages of their evolution without decaying to qss. finally, we discuss the possible evolutionary paths of phss. | quark deconfinement in neutron stars and astrophysical implications |
the deep underground neutrino experiment (dune) liquid argon time projection chambers will record the burst of neutrinos from the core collapse of a massive star in the milky way neighborhood. dune's liquid argon has unique sensitivity to the electron neutrino component of the burst. this poster will describe recent progress on reconstruction of supernova burst neutrinos in dune. | supernova neutrino detection in dune |
results of the numerical simulations of the neutrino angular distribution in core-collapse supernova were analyzed. as analysis shown, the neutrino angular distribution function can be approximated by a one-parametric gaussian function. the proposed approximation describes about 90% of all neutrinos in the core-collapse supernova at times t ≳ 0.2 sec after a core bounce and relatively large distances from proto-neutron-star center. therefore, it could be a good analytical approximation of the numerical data. at small values of time and distance an accuracy of this approximation significantly decreases. | analytical approximation of neutrino distribution function in core-collapse supernova |
the photon detection system (pds) is a subsystem detector of the deep underground neutrino experiment (dune). it measures the scintillation light signal and allows determination of the time of occurrence of an event of interest with much higher precision than charge collected from ionization in the liquid argon time projection chambers and provides a complementary measurement of the deposited energy. this talk will report on simulation studies of calorimetric energy measurement of neutrinos from supernova neutrino bursts (snb) in dune using the pds. funding acknowledgement: us department of energy award de-sc0017740. collaborations: dune. | calorimetric energy measurement for supernova neutrinos using the dune photon detection system |
the micro-x sounding rocket uses a transition edge sensor (tes) array to make x-ray observations. the improved energy resolution of tess compared to traditional space-based x-ray detectors brings new precision to both supernova observations and the x-ray search for sterile neutrino dark matter. current x-ray observations disagree over the potential presence of a 3.5 kev x-ray line consistent with a sterile neutrino interaction, and micro-x is in a unique position to establish or refute the presence of this line. we present the design considerations of the instrument and expectations for flight observations, with special emphasis given to the prospects of sterile neutrino studies. | prospects for sterile neutrino observations with the micro-x sounding rocket |
recent progress of neutrino detectors makes it possible to detect pre-sn neutrinos, which are emitted from the core of massive stars before supernova explosions. pre-sn neutrino observations will become an alarm for supernovae. we hence calculate the number luminosity and energy spectra of pre-sn neutrinos from the 15 m ⊙ progenitor based on the state-of-the-art calculations of massive stars. we find that the number luminosity of ve ’s is {l}nv∼ {10}55,{10}57{\text{s}}-1 before core collapse and core bounce, respectively, whereas that of {\bar{v}}e’s becomes largest around core collapse {l}nv∼ {10}53{\text{s}}-1. we then estimate the number of neutrino events at neutrino detectors taking neutrino oscillations into the obtained luminosities and spectra. we find that an alarm is issued a few days before the explosion by detecting {\bar{v}}e’s at liquid-scintilation type detectors if the progenitor is located at 200 pc. finally, we perform a systematic study of pre-sn neutrino emission for 7 progenitor models with different initial masses. we find that the difference of the number luminosities is ~ 1 order and the dependence of the initial mass have to be taken into the theoretical predictions of pre-sn neutrino observations. | pre-supernova neutrino emission from massive stars and their detection |
we produced figures of merit that show how many neutrinos can be detected for supernovae as a function of distance and compactness. compactness is the ratio of the mass contained within the radius of the progenitor at the time of core bounce as defined by o'connor and ott (2011). this was used to quantify the sensitivity of a 40-kiloton liquid argon detector to core-collapse supernovae. we calculated neutrino event rates for a range of compactnesses. compiling the results of the neutrino fluxes with a probability distribution of supernovae with respect to compactness and a probability distribution of supernovae with respect to distance allows the generation of useful data visualizations. specifically, it produces a histogram that shows the number of neutrinos likely to be detected as well as the probability of seeing core-collapse supernovae as a function of both compactness and distance. with these histograms, we are able to determine how many models can be observed given a neutrino event threshold for this type of detector. these methods can be repeated for other types of detectors in the future. | quantifying liquid argon neutrino detector sensitivity to supernova burst neutrinos |
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. | supernova neutrino burst search at kamland |
astrobites reports on an updated neutrino detector that may be able to alert us to impending supernovae hours in advance. | a beginner's guide to predicting supernovae |
we calculate the emissivity due to neutrino-pair production in e + e - annihilation in the context of a 331 model and a left-right symmetric model in a way that can be used into realistic supernova model to evaluate the energy lost in the form of neutrinos. | emissivity of neutrinos in supernova via the pair-annihilation process beyond the standard model |
supernova explosions play a wide role in astrophysics by producing compact remnants (neutron stars, black holes) and the synthesis and injection of many heavy elements into the galaxy. because they are produced in some of the most extreme conditions in the universe, they can also probe the physics in extreme conditions (matter at nuclear densities, neutrinos, etc.). to quantify the impact of supernovae on both fundamental physics and our understanding of the universe, we must leverage a broad set of probes of this engine. the properties (mass, spin and kick distributions) of the compact remnants formed in these explosions provide decisive clues into the nature of the core-collapse supernova engine. here we review the current supernova engine models and the constraints on these models placed by compact remnants. | compact remnant properties and the supernova engine |
first three-dimensional, first-principle simulations of core-collapse supernovae have become possible in the recent past. they demonstrate the basic viability of the neutrino-driven mechanism for powering the explosions of the majority of supernova progenitors. however, important questions still remain to be settled. these include basic technical aspects such as the influence of the numerical resolution or the method of the neutrino-transport treatment, as well as important physics aspects such as the initial stellar conditions and still missing physics, for example effects of muon formation and neutrino oscillations. the talk will review the current status of 3d supernova modeling and of our understanding of neutrino-driven explosions. it will also provide an outlook on current progress for answering the open questions mentioned. | neutrino-driven explosions in 3d supernova simulations |
we explore the neutrinos from decays of stopped atmospheric muons in the earth. in terms of the atmospheric muon flux at the sea-level and the average muon range r, we derive the depth distribution of stopped muons in the earth. the stopped μ^- can be captured by different nuclei in the rock. based on the mean-life of captured μ^- and the average muonic capture probabilities of different elements, we find that about 60% stopped μ^- can decay and produce the low energy neutrinos (< 53 mev). then we calculate the ν_e , \bar{ν}e , νμ and \bar{ν}_μ fluxes from all stopped μ^+ and μ^- in the earth, which have about 10%, 6%, 3% and 7% of the corresponding atmospheric neutrino fluxes. the new neutrino source is very helpful for us to investigate the diffuse supernova neutrinos and some related topics. | neutrinos from decays of stopped atmospheric muons in the earth |
we observed ztf candidate sn2020lls (reusch et al, gcn 27872), a possible counterpart to high-energy neutrino icecube-200530a (stein et. al, gcn 27865), using the not/alfosc spectrograph on 12 june 2020. we classify sn2020lls as a type ic supernova without broad-line features. sn2020lls was detected with forced photometry by ztf in i-band images 1 day prior to neutrino detection. an explosion time estimator puts the supernova explosion time 8 (+5/-2) days prior to neutrino detection. both points suggest that the neutrino was detected several days after explosion. the apparent delay between supernova explosion and neutrino detection is inconsistent with a choked-jet neutrino production scenario. therefore, sn2020lls is likely not related to the high-energy icecube neutrino icecube-200530a. at2019fdr remains a source candidate. | icecube-200530a - sn2020lls likely unrelated |
i will describe recent results on the role of jets in exploding core collapse supernovae (ccsne) and in powering intermediate luminosity optical transients (ilots), and will compare the results with the most recent observations and with other theoretical studies. i will discuss new ideas of processes that become possible by jets, such as the jittering jets explosion mechanism of massive stars aided by neutrino heating, the formation of type iib ccsne by the grazing envelope evolution (gee), and common envelope jets supernovae (cejsne). | the role of jets before, during, and after explosions and in powering ilots |
the next galactic core-collapse supernova (ccsn) has already exploded, and its electromagnetic (em) waves, neutrinos, and gravitational waves (gws) may arrive at any moment. we present an extensive study on prospective detection scenarios for gws from ccsne in the milky way, large magellanic cloud, ngc 6822, m31, and m82. we make statements on the detectibility of astrophysically-motivated signals (including waveforms from state-of-the-art 3d ccsn simulations). we utilize real gw detector data, recolored to the predicted noise power spectral densities of the advanced ligo (aligo) and advanced virgo (advirgo) detectors at early (~2015-2017) and late (~2018-2020) times. we consider various uncertainties in the gw arrival time to investigate sensitivity improvements when arrival time information is provided by neutrino or em information. this research was supported in part by nsf award nos. phy-1151197 and phy-1404569. | observing gravitational waves from the next nearby core-collapse supernova |
we derived both neutrino neutral current and charged current interactions based on random phase approximation (rpa). the rpa is treated as an extendable platform where other ``many body effect modules'', such as nucleon potential mean field corrections and collisional broadening, can be easily added. furthermore, the rpa consistently relates the neutrino response with an equation of state (eos). in this work, we employed density-dependent nucleon effective mass, landau fermi liquid parameters and nucleon potential, which are all derived from a skyrme type eos (nrapr), in the rpa approximation. we further discuss the possibilities of estimating the uncertainties of neutrino response coming from the skyrme eos parameters. finally, we discuss approximations beyond rpa at low densities to find an appropriate method to describe the dynamic neutrino response that is consistent with the model-independent virial approximation of neutrino static response. | the neutrino opacities in core-collapse supernovae: a systematic way to describe neutrino interactions for a wide range of densities at finite temperature |
the detection of two transition metals in the remnant of a supernova lends support to a mechanism for the explosion of a massive star called the neutrino-driven convective supernova engine, where a plume of hot material re-invigorates a stalled shockwave. | neutrino heating re-starts the stalled engine |
core-collapse supernovae are the end stage of massive star evolution and are central to many aspects of astrophysics. they are the birth site of both neutron stars and black holes and their shocks are responsible for spreading the products of stellar evolution throughout the galaxy and regulating star formation. despite their importance and decades of research, the precise mechanism that converts the initial implosion of the collapsing iron core to an explosion that unbinds the majority of the star is unknown. however, we know that the majority of the energy released is ultimately radiated in neutrinos and that the physics of neutrino transport and neutrino heating-among many other aspects-must be treated carefully when modelling the core-collapse supernova central engine. in this talk, i will present recent simulations of core-collapse supernovae from the flash hydrodynamics code. we perform two dimensional, neutrino transport simulations using several progenitors. we test the influence of general relativity by using a pseudorelativistic potential that effectively models gr. we show that the more compact protoneutron star predicted from gr increases the neutrino heating and can lead to explosions where the corresponding newtonian simulations fail. | two dimensional simulations of core-collapse supernovae with neutrino transport in flash |
core-collapse supernovae emit about 99% of their gravitational energy in a burst of neutrinos. detecting such a neutrino signal would provide a valuable information both on the neutrino properties and on the stellar collapse physics. the large liquid scintillator detectors used in the nova experiment provide a possibility to detect such a signal. a dedicated trigger system was developed for nova to perform the search of inverse beta decay neutrino interaction candidates in real time and is able to detect the supernova burst within seconds latency and save the data from detectors for further study. this system has been running in stable mode since november 2017. a parallel effort is on-going to develop background rejection and event selection techniques for an offline analysis of these neutrinos. | detection of galactic supernova neutrinos at the nova experiment |
conventionally, neutrino-transparent nuclear matter is said to be in beta equilibrium if the electron and proton chemical potentials add up to the neutron chemical potential. we find that at temperatures above 1 mev, which are reached in neutron star mergers and supernovae, the traditional criterion of beta equilibrium needs to be modified by adding an isospin chemical potential of order 10 mev. this modification of beta equilibrium alters the direct and modified urca rates for densities above and below the direct urca threshold density, which has implications for the bulk viscosity of neutron star mergers. | beta equilibrium in neutron star merger conditions |
binary neutron star mergers produce thermal neutrinos that can be detected using detectors such as super-kamiokande and the dune far detector. using a software called snowglobes we can simulate a neutrino flux from a merger at 10 kpc and calculate its interaction and event distribution rates. we found that for said merger 4,000 events in dune will be detected at 10 kpc, of which 3,500 will be electron neutrino on argon 40 interactions. we also saw that, comparing the flux for this merger and for a core-collapse supernova, while the event rates for both were similar, the neutrino flux for this merger was higher by one order of magnitude than the flux for the supernova. | calculation of neutrino events in binary neutron star mergers |
the supernova early warning system (snews) is a public alert system consisting of neutrino detectors around the world. in the current era of multi-messenger astrophysics (mma), there are new opportunities for snews to optimize their science reach from the next galactic supernova beyond a simple early alert. there appeared a need to upgrade the cyberinfrastructure for scalability and maintainability. the snews collaboration was looking for ways to adapt foreign software tools standardized for messaging between the coincidence server and neutrino detectors. the scalable cyberinfrastructure for multi-messenger astrophysics (scimma) project has developed a publish-subscribe system called hopskotch that would significantly simplify the task for physicists to maintain the software. this presentation will introduce the design and development of snews 2.0 prototype that incorporates the hopskotch software into its internal network. it will also present the snews-customized software support provided by scimma as well as future software maintenance and deployment details. | prototype of the supernova early warning system using hopskotch publish-subscribe system |
we searched icecube online track-like neutrino candidates (gfu) detected in a [-500,500] second interval about the ligo-virgo trigger g296853. we compared the candidate source directions of 4 temporally-coincident neutrinos to the bayestar skymap, with the following parameters: # dt[s] ra[deg] dec[deg] e[tev] sigma[deg] ------------------------------------------------------------------ 1. -310.02 65.9 -5.2 1.11 0.5 2. -128.45 74.0 -29.2 52.68 0.2 3. 361.60 164.0 -14.6 20.50 0.5 4. 438.49 121.1 -64.8 81.83 2.1 (dt--time from gw in [seconds]; ra/dec--sky location in [degrees]; e--reconstructed secondary muon energy in [tev]; sigma--uncertainty of direction reconstruction in [degrees]) the analysis found no coincident online track-like neutrino candidates detected by icecube within the 500 second window surrounding g296853 within the bayestar skymap. a coincident neutrino-gw skymap has been posted to gracedb (< https://gracedb.ligo.org/apiweb/events/g296853/files/ coinc_skymap_initial_icecube.png,0>). a json-formatted list of the above neutrinos can be downloaded from gracedb at: <https://gracedb.ligo.org/ apiweb/events/g296853/files/icecubeneutrinolist.json,0> in addition, we are performing coincident searches with other icecube data streams, including the high-energy starting events (hese) and supernova triggers. hese events have typical energies > 60 tev and start inside the detector volume, leading to a relatively pure event sample with a high fraction of astrophysical neutrinos. the sn trigger system is sensitive to sudden increases in photomultiplier counts across the detector, which could indicate a burst of mev neutrinos. we will submit separate gcn circulars if coincident hese or sn triggers are found. the icecube neutrino observatory is a cubic-kilometer neutrino detector operating at the geographic south pole, antarctica. for a description of the icecube realtime alert system, please refer to < http://adsabs.harvard.edu/cgi-bin/bib_query?arxiv:1610.01814>; for more information on joint neutrino and gravitational wave searches, please refer to <http://adsabs.harvard.edu/cgi-bin/bib_query?arxiv:1602.05411>. | ligo/virgo g296853: icecube neutrino observations |
the search for neutrinos from past supernovae is getting an upgrade as japan's super-kamiokande experiment begins adding gadolinium powder to its giant water-based detector. | powdering up for neutrinos |
about 90% mass of matter in the universe is dark matter (dm) and most of its properties remain poorly constrained since it does not interact with electromagnetic and strong forces. to constrain the properties of dm, studying its effects on stellar objects is one of the methods. in [leung et al., phys. rev. d 87, 123506 (2013); leung et al., astrophys. j. 812, 110 (2015)] we have shown that the dark matter admixture can significantly lower the chandrasekhar mass of a white dwarf and also its corresponding explosion as a type ia supernova (sne ia). this type of objects may explain some observed sub-luminous sne ia. depending on their stellar evolution path and interactions with companion stars, such objects can also undergo a direct collapse to form neutron stars (nss) instead of explosion. here we present results of one-dimensional hydrodynamics simulations of a ns with admixed dm. the dm is assumed to be asymmetric and in the form of an ideal degenerate fermi gas. we study how the admixture of dm affects the collapse dynamics, its neutrino signals and the properties of the proto-ns. possible observational signals are also discussed. | the effects of admixed dark matter on accretion induced collapse |
the cryogenic apparatus for precision tests of argon interaction with neutrinos (captain) is an experimental program to measure critical neutrino interaction cross sections in argon for the dune long-baseline program. these cross sections are important for understanding and improving the energy resolution of measurements for neutrino oscillations and supernova detection in argon. the full captain detector is a 5-ton fiducial volume liquid argon (lar) time-projection chamber (tpc) with an independently triggered photon detection system (pds) for fast-timing capabilities on accelerators. to test the full captain concept, the 1-ton fiducial volume mini-captain detector has been deployed. mini-captain is another lar tpc with pds. it was recently deployed to the weapons neutron research (wnr) facility at los alamos national laboratory to measure high-energy neutron interactions in argon. the wnr is a pulsed accelerator capable of delivering neutrons up to 800 mev in energy. in this talk, i will report on the analysis of the first time-of-flight tagged, high-energy neutron response in liquid argon from our february 2016 run. i will also highlight a second neutron run at the wnr scheduled for summer 2017 and discuss the implications these data have on the future captain program. | the mini-captain neutron run and future captain program |
the cenns-10 detector is a liquid argon chamber currently running at the sns at ornl to observe nuclear recoils from coherent elastic neutrino-nucleus scattering (cevns) and is one of several technologies implemented by the coherent collaboration to measure the cevns process' dependence on nuclear size. the observation and measurement of cevns is vital to understanding energy propagation in supernovae, a test for physics beyond the standard model, an irreducible background for dark matter direct detection, and a probe into nuclear structure. the functioning of the detector depends on its ability to see light from the neutrino-nuclear scattering, which produces extreme uv radiation. to attain optimum light yield in the detector, several optical measurements and changes were necessary. this poster will discuss these measurements, as well as the future expansion of the liquid argon system. | optimizing scintillation light collection in the cenns-10 liquid argon neutrino-nucleus scattering detector |
dune will be an underground neutrino oscillation experiment that will perform precision measurements of the pmns mixing parameters, determine unambiguously the mass ordering and discover leptonic cp violation. it also comprises a rich non-accelerator physics program as the detection of supernova neutrinos, nucleon decay and bsm physics. one of the modules of the dune is proposed to be dual-phase lartpc. inside this module, a light detection system (lds) is being designed, consisting on an array of photomultiplier tubes and a calibration system based on optical fibers. to fulfil the physics program, the lds is aimed to comply with certain physics requirements. those are to provide a detection efficiency of more than 90% for a supernova burst within the milky way and an event time reconstruction efficiency of more than 90% with a signal purity of more than 90% across the active volume for proton decay event candidates. the present document summarizes the status of the simulation studies of the light detection in dune dual-phase, and the expected performance of the lds, that will be part of the forthcoming technical design report of dune. | light detection in dune dual phase |
we present a plan to dope microboone, an 85-ton active-volume liquid argon time projection chamber (lartpc) located at fermilab, with radon. microboone has been successfully detecting ~gev energy neutrinos from the booster neutrino beam since 2015, however few studies have been performed at mev energies. the associated decay activity from the radon will allow us to study detector properties not easily accessible at higher energies, namely mev-scale energy resolution and electron diffusion. such studies are especially important for the deep underground neutrino experiment (dune), a multi-kiloton-scale, next-generation long-baseline experiment and its low-energy physics goals, such as supernova neutrino reconstruction. this talk will present an overview of the doping program, its goals and its benefits to future lartpcs. | doping the microboone lartpc with radon |
super-kamiokande (super-k) is the world largest water cherenkov detector built in the kamioka mine, japan. one of the most important subjects of super-k is to detect supernova neutrinos. in case of a supernova which happens near the center of our galaxy, several thousand neutrino events will be detected by super-k, and the direction of the supernova can be obtained with an uncertainty of few degree. in this presentation, an introduction to our online supernova monitoring system is given, and future plans related to the supernova neutrino detection are discussed. | supernova detection at super-kamiokande |
we apply the convolution (folding) method in neutrino physics studies. we focus on its use to explore the response of some nuclear detectors to the energy spectra of laboratory neutrinos. after calculating the neutrino-nucleus cross sections (within the context of a nuclear model) for a neutrino detector, the obtained cross section values must be folded with a specific neutrino- energy distribution. in the present work we use the v-distribution of pion-muon decay at rest neutrino beams created in muon factories like the fermilab, j-parc, and other laboratories. due to the fact that neutrino-nucleus interactions are very weak, the evaluated cross sections are small (~ 10-42cm2). thus, one needs a very fine convolution tool to obtain accurate description of the v-signals (laboratory, supernova neutrinos, etc.) recorded at some nuclear detectors. | computational treatment of the neutrino signals produced in nuclear detectors |
using online data from the km3net detector, we have performed a follow-up analysis of the recently reported gravitational-wave (gw) burst candidate s191110af (gcn #26222) to investigate the possibility that this burst was emitted by a core-collapse supernova (ccsn) event. km3net can detect ~10 mev neutrinos from a galactic ccsn through a collective rise of the photomultiplier (pmt) detection rates on top of the noise due to the cherenkov light produced by the interaction of electron antineutrinos through inverse beta decay. this is expected mostly during the ccsn accretion phase (lasting a few hundred ms) where most of the electron antineutrinos are supposed to be emitted [1]. no ccsn trigger in the km3net/orca online infrastructure was detected during a 400 ms time-window, starting at the time of the gw trigger, while 0.8 events are expected on average from the background at trigger time. using feldman and cousins approach, a preliminary 90% confidence level upper limit on the number of signal events is estimated. assuming two progenitor models from the garching group [2] with masses of 27 msun and 11.2 msun, we derive an upper limit on the distance of the potential source of 11.4 kpc and 5.7 kpc respectively. moreover, assuming a quasi-thermal neutrino spectrum as in [2] with a spectral pinching parameter value of 3 and a mean neutrino energy of 15 mev and assuming that 70% of the energy is released in the 400 ms, the total energy emitted into neutrinos from this gw burst candidate is determined to be e < 2.8e53 erg at 10 kpc. km3net detectors are currently under construction in the mediterranean sea. the orca detector is nowadays composed of an array of 4 instrumented lines, each containing 18 digital optical modules hosting 31 directional pmts. it is equivalent to a 3 kton ccsn neutrino detector. with the current configuration, orca detector can detect a ccsn at 5 sigma up to 3.5 and 7.5 kpc respectively for the low and high-mass progenitor considered in the ccsn neutrino flux models of the garching group. [1] m. colomer, m. lincetto et al. (on behalf of the km3net collaboration), pos(icrc2019)857. [2] i. tamborra et al., phys. rev. d, 90 (2014). | ligo/virgo s191110af: upper limits from km3net mev neutrino search. |
in the delayed explosion scenario of a core-collapse supernova, the accretion phase shows pronounced convective over-turns and a low-multipole hydrodynamic instability, the so-called standing accretion shock instability (sasi). neutrino signal variations from the first full-scale three-dimensional core-collapse supernova simulations with sophisticated neutrino transport are presented as well as their detection perspectives in icecube and hyper-kamiokande. | fast-time variations of supernova neutrino fluxes and detection perspectives |
the convection-enhanced paradigm behind core-collapse supernovae (sne) invokes a multi-physics model where convection above the proto-neutron star is able to convert the energy released in the collapse to produce the violent explosions observed as sne. over the past decade, the evidence in support of this engine has grown, including constraints placed by sn neutrinos, energies, progenitors and remnants. although considerable theoretical work remains to utilize this data, our understanding of normal sne is advancing. to achieve a deeper level of understanding, we must find ways to compare detailed simulations with the increasing set of observational data. here we review the current constraints and how we can apply our current understanding to broaden our understanding of these powerful engines. | studying supernovae under the current paradigm |
coherent elastic neutrino-nucleus scattering (cevns) is a neutral-current process in which a neutrino scatters off an entire nucleus, depositing a tiny recoil energy. the process is important in core-collapse supernovae and also presents an opportunity for detection of the burst of neutrinos ejected in the collapse. the cevns process dominates low-energy interactions (tens of mev) but produces very little energy deposition from the target nuclear recoil. the challenge of its observation is reduced somewhat if a nearby core-collapse supernova acts as a high-flux source, producing thousands of cevns events in larger detector volumes over mere seconds. for detectors making use of scintillation to record particle energy loss, the effect would be a uniformly distributed, isotropic scintillation, a ''cevns glow'', throughout the detector. this overall time-localized increase in photon activity could be measurable, giving us critical constraints on the total energy and flux of the explosion. this talk will cover prospects for supernova burst detection via cevns in existing and future large detectors of liquid argon and organic liquid scintillator and present a semi-analytic method for obtaining the detected photon spectra of both the cevns signal and major expected backgrounds. | observation of supernova neutrino bursts via cevns |
in an analysis finished at 2017-08-19 19:07:25, we searched icecube online track-like neutrino candidates (gfu) detected in a [-500,500] second interval about the ligo-virgo trigger g298389. we compared the candidate source directions of 6 temporally-coincident neutrinos to the lib skymap, with the following parameters: # dt[s] ra[deg] dec[deg] e[tev] sigma[deg] ------------------------------------------------------------------ 1. -29.47 104.5 -32.2 98.85 1.9 2. -27.58 78.2 64.7 0.91 1.0 3. 28.18 7.7 1.8 3.87 0.3 4. 193.16 237.2 7.0 0.64 0.7 5. 434.75 122.5 -9.4 7.92 0.3 6. 477.83 0.3 -66.2 141.53 0.2 (dt--time from gw in [seconds]; ra/dec--sky location in [degrees]; e--reconstructed secondary muon energy in [tev]; sigma--uncertainty of direction reconstruction in [degrees]) the analysis found no coincident online track-like neutrino candidates detected by icecube within the 500 second window surrounding g298389 within the lib skymap. a coincident neutrino-gw skymap has been posted to gracedb (<https://gracedb.ligo.org/apiweb/events/g298389/files/coinc_skymap_initial_icecube.png,0>). a json-formatted list of the above neutrinos can be downloaded from gracedb at: <https://gracedb.ligo.org/apiweb/events/g298389/files/icecubeneutrinolist.json,0> in addition, we are performing coincident searches with other icecube data streams, including the high-energy starting events (hese) and supernova triggers. hese events have typical energies > 60 tev and start inside the detector volume, leading to a relatively pure event sample with a high fraction of astrophysical neutrinos. the sn trigger system is sensitive to sudden increases in photomultiplier counts across the detector, which could indicate a burst of mev neutrinos. we will submit separate gcn circulars if coincident hese or sn triggers are found. the icecube neutrino observatory is a cubic-kilometer neutrino detector operating at the geographic south pole, antarctica. for a description of the icecube realtime alert system, please refer to <http://adsabs.harvard.edu/cgi-bin/bib_query?arxiv:1610.01814>; for more information on joint neutrino and gravitational wave searches, please refer to <http://adsabs.harvard.edu/cgi-bin/bib_query?arxiv:1602.05411>. | ligo/virgo g298389: icecube neutrino observations |
the gravitational collapse of a massive star leads to the strong emission of gravitational waves and neutrinos during the first few seconds of the supernova event. multi-messenger observations offer, thus, a unique window on the dynamics that regulate the explosion mechanism and the physical properties of the still-forming central proto-neutron star (pns). in recent years, numerical models of core-collapse supernovae (ccsn) have started to produce quantitative predictions of both gravitational waves and neutrino emissions which provide the key ingredients necessary to constraint the physics of the explosion engine from actual observational data. despite the fundamental role that strong magnetic fields play in the case of exceptionally energetic stellar explosions (e.g. long grbs, hypernovae, superluminous supernovae), their impact on the multi-messenger emission from ccsn remains still largely unknown. we present results from recent studies aimed at quantifying the impact of dynamo-generated magnetic fields on the neutrino and gravitational waves emitted at the formation of a stellar compact object. we show how magnetic fields, by modifying the rotational profile of the proto-neutron star, weaken the development of large-scale instabilities connected to strong multi-messenger signals. however, this can also lead to a broadening of the spectral shape of the gw signal due to the magnetic field's impact on rotation and possibly the onset of the kink instability within the pns. we finally display how current and upcoming neutrino detectors (e.g. km3net, dune, darkside) will be sensitive to the effects of rotation and strong magnetic fields predicted by our numerical models. | the impact of rotation and dynamos on the multi-messenger emission of core-collapse supernovae |
a core-collapse supernova burst (snb) releases 99% of a star's gravitational potential energy via neutrinos over a period of several seconds. these neutrinos have energies in the few to 10s of mev range. lack of knowledge of low-energy neutrino cross sections will limit the amount of physics extracted during a future snb. in particular, the electron neutrino-argon charged-current inelastic interaction (νecc) cross section has never been measured at the snb neutrino energy range. furthermore, different cross section calculations are only theoretically motivated and contain significant variations when comparing different models. the coherent liquid argon (lar) detector, known as cenns-10, observes neutrinos with energies in the 10s of mev at the spallation neutron source at oak ridge national laboratory. the proposed upgrade to cenns-10, known as cenns-750, will have a larger fiducial volume and the possibility to optimize both the detector design and data acquisition to detect the νecc interaction. the coherent lar detectors provide current and future opportunities to study the νecc interaction at the relevant neutrino energy range for snb neutrinos. this talk will detail simulation studies focused on coherent lar detector sensitivity to the νecc interaction. department of energy. | studying neutrino charged-current interactions in the coherent liquid argon detectors |
neutrino transport is among the most computationally intensive components of multi-physics, core-collapse supernovae (ccsne) simulations. a complete boltzmann treatment of multi-angle, multi-energy 3d neutrino transport will require sustained exascale computing and beyond. even multi-energy moments treatments of 3d neutrino transport will only allow a limited set of models to be considered. this project is a work in progress that attempts to combine the computational efficiency of a grey approach with as much of the realism of boltzmann and moments based neutrino transport as possible in order to enable numerous multi-physics, 3d simulations of ccsne. using the general astrophysics simulation system (genasis) framework, an object-oriented, fortran code utilizing both openmp and mpi, this project will be an investigation of multidimensional ccsne simulations spanning a large parameter space of progenitor characteristics, e.g. mass, rotation, and perturbation methods. current progress includes implementation of grey, two-moment neutrino-transport, relativistic multipole gravity, realistic equation of state table interface, and modern neutrino opacities into genasis. various tests have verified the accuracy of each implementation individually and in conjunction together, culminating in a simulation of a realistic progenitor with limited neutrino interactions. | towards 3d parameter space studies of ccsne with grey, two-moment neutrino transport |
a beyond-standard-model interaction between neutrinos could show up in future supernovae observations. | supernovae could confess neutrinos' secrets |
using online data from the km3net orca detector, we have performed a follow-up analysis of the recently reported gravitational-wave (gw) burst candidate s200114f (gcn #26734) to investigate the possibility that this burst was emitted by a core-collapse supernova (ccsn) event. km3net can detect ~10 mev neutrinos from a galactic ccsn through a collective rise of the photomultiplier (pmt) detection rates on top of the noise, due to the cherenkov light produced by the interaction of electron antineutrinos through inverse beta decay. this is expected mostly during the ccsn accretion phase (lasting a few hundred ms) where most of the electron antineutrinos are supposed to be emitted [1]. two events were observed with the ccsn trigger in the km3net/orca online infrastructure during a 400 ms time-window starting at the time of the gw trigger while 1.4 events are expected on average from the background at trigger time (p-value = 40.1%). km3net/arca, due to a programmed upgrade of the on-shore station in capo passero, is off temporarily. using the feldman and cousins approach, a 90% confidence level upper limit on the number of signal events is estimated. assuming two progenitor models from the garching group [2] with masses of 27 msun and 11.2 msun, we derive a lower limit on the distance of the potential source of 11.5 kpc and 6.1 kpc respectively. moreover, assuming a quasi-thermal neutrino spectrum as in [2] with a spectral pinching parameter value of 3 and a mean neutrino energy of 15 mev and assuming that 70% of the energy is released in the 400 ms, we estimate the total energy emitted into neutrinos from this gw burst candidate to be e < 2.9e53 erg at 10 kpc. the km3net detectors are currently under construction in the mediterranean sea. the km3net/orca detector currently comprises an array of 4 detection lines and km3net/arca detector hosts one line. each detection line contains 18 digital optical modules hosting 31 directional pmts. [1] m. colomer, m. lincetto et al. (on behalf of the km3net collaboration), pos(icrc2019)857 [2] i. tamborra et al., phys. rev. d, 90 (2014) | ligo/virgo s200114f: constraints on a ccsn origin from km3net mev neutrino search. |
the helium and lead observatory (halo) is a dedicated supernova neutrino detector in snolab, which is built from 79 tons of surplus lead and the helium-3 neutron detectors from the sno experiment. it is sensitive primarily to electron neutrinos, and is thus complementary to water cerenkov and organic scintillation detectors which are primarily sensitive to electron anti-neutrinos. a comparison of the rates in these complementary detectors will enable a flavor decomposition of the neutrino flux from the next galactic core-collapse supernova. we have tentative ideas to build a 1000-ton halo-2 detector in the gran sasso laboratory by using the lead from the decommissioned opera detector. we are exploring several neutron detector technologies to supplement the existing helium-3 detectors. we welcome new collaborators to join us. this research is supported by the nrc and nserc (canada), the us doe and nsf, and the german rise program. | the halo / halo-2 supernova neutrino detectors |
we study the consequence of a hadron-quark phase transition in failing core-collapse supernovae, which give birth to stellar-mass black holes. in models with a range of progenitor compactness, the protoneutron star collapses and bounces for a second time due to the phase transition. however, this second bounce cannot revive the supernova shock. instead, the protoneutron star oscillates with the excess kinetic energy and emits a train of neutrino pulses with a period of ~ms. black-hole formation takes place in a third collapse. the periodic neutrino signal can be a strong indicator for the hadron-quark phase transition in failing core-collapse supernovae if detected in the future. this work is supported by the swedish research council (project no. 2018-04575 and 2020-00452). | possible neutrino signature of hadron-quark phase transition in failing core-collapse supernovae |
i will report on recent calculations of neutrino-antineutrino pair production from bremsstrahlung processes in hadronic collisions and consider temperature conditions relevant for core collapse supernovae. earlier studies on bremsstrahlung from neutron-neutron collisions showed that the approximation used in typical supernova simulation to model this process differs by about a factor of 2 from predictions based on chiral effective field theory, where the chiral expansion of two-body forces is considered up to the next-to-next-to-next-to-leading order. when the density of neutrons is large enough this process may compete with other non-hadronic reactions in the production of neutrinos, in particular in the case of μ and τ neutrinos, which are not generated by charged-current reactions. a natural question to ask is then: what is the effect of neutrino pair production from collisions of neutrons with finite nuclei? to tackle this question, we recently have addressed the case of neutron- α collisions, given that in the p-wave channels the neutron- α scattering features a resonance near 1 mev. we find that the resonance leads to an enhanced contribution in the neutron spin structure function at temperatures in the range of 0 . 1 - 4 mev. for significant density fractions of α in this temperature range, this process is competitive with contributions from neutron-neutron scattering. triumf receives federal funding via a contribution agreement with the national research council of canada. this work was supported in parts by the natural sciences and engineering research council (grant number sapin-2015-0003). | neutrino-antineutrino pair production by hadronic bremsstrahlung |
the important result of the iron core collapse simulation is the formation of the convectively unstable regions in the center and in the region of the accretion. the large region near the center suitable for the convective insatiability exists during 10 ms. in the frame of 3d hydrodynamic simulations with taking into account self-gravity i illustrate the possibility of the developing of the large-scale convection during such short time. another important result from the viewpoint supernova explosion is the huge neutrino energy in the degenerate convective bubble about 100 mev in compare with the thermal neutrino 10 mev from the neutrino-sphere. large neutrino energy is important for the explanation of the supernova explosion. | the supernova explosion and the large-scale convective instability in a proto-neutron star |
the next galactic core-collapse supernova (ccsn) has already exploded, and its electromagnetic (em) waves, neutrinos, and gravitational waves (gws) may arrive at any moment. we present an extensive study on the potential sensitivity of prospective detection scenarios for gws from ccsn sources within 5mpc, using realistic noise at the predicted sensitivity of the advanced ligo and advanced virgo detectors for 2015, 2017, and 2019. we make statements on the detectability of the core collapse event for sources within the galaxy and large magellanic cloud, for which there will be an associated neutrino burst, and consider the exclusion of extreme post-core collapse emission models for more distant sne with an associated em signature. given a detection of gw from core collapse, we discuss the potential to infer the ccsn explosion mechanism. | observing gravitational waves from core-collapse supernovae in the advanced detector era |
we propose and experimentally demonstrate an efficient scheme for bidirectional and deterministic photonic communication between two remote superconducting modules. the two chips, each consists of a transmon, are connected through a one-meter long coaxial cable that is coupled to a dedicated "communication" resonator on each chip. the two communication resonators hybridize with a mode of the cable to form a dark "communication mode" that is highly immune to decay in the coaxial cable. we overcome the various restrictions of quantum communication channels established by other recent approaches in deterministic communication for superconducting qubits. our approach enables bidirectional communication, and eliminates the high insertion loss and large volume footprint of circulators. we modulate the transmon frequency via a parametric drive to generate sideband interactions between the transmon and the communication mode. we demonstrate bidirectional single-photon transfer with a success probability exceeding 60%, and generate an entangled bell pair with a fidelity of 79.3 ± 0.3%. | deterministic bidirectional communication and remote entanglement generation between superconducting qubits |
it was recently suggested that the discrepancy between two methods of measuring the lifetime of the neutron may be a result of an unseen decay mode into a dark matter particle which is almost degenerate with the neutron. we explore the consequences of this for the properties of neutron stars, finding that their known properties are in conflict with the existence of such a particle. | implications of neutron star properties for the existence of light dark matter |
we present the results of measurements demonstrating the efficiency of the edelweiss-iii array of cryogenic germanium detectors for direct dark matter searches. the experimental setup and the fid (fully inter-digitized) detector array is described, as well as the efficiency of the double measurement of heat and ionization signals in background rejection. for the whole set of 24 fid detectors used for coincidence studies, the baseline resolutions for the fiducial ionization energy are mainly below 0.7 kevee (fhwm) whereas the baseline resolutions for heat energies are mainly below 1.5 kevee (fwhm). the response to nuclear recoils as well as the very good discrimination capability of the fid design has been measured with an ambe source. the surface β- and α-decay rejection power of rsurf < 4 × 10-5 per α at 90% c.l. has been determined with a 210pb source, the rejection of bulk γ-ray events has been demonstrated using γ-calibrations with 133ba sources leading to a value of rγ -mis-fid < 2.5 × 10-6 at 90% c.l.. the current levels of natural radioactivity measured in the detector array are shown as the rate of single γ background. the fiducial volume fraction of the fid detectors has been measured to a weighted average value of (74.6 ± 0.4)% using the cosmogenic activation of the 65zn and 68,71ge isotopes. the stability and uniformity of the detector response is also discussed. the achieved resolutions, thresholds and background levels of the upgraded edelweiss-iii detectors in their setup are thus well suited to the direct search of wimp dark matter over a large mass range. | performance of the edelweiss-iii experiment for direct dark matter searches |
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