abstract stringlengths 3 192k | title stringlengths 4 857 |
|---|---|
we use data from the coherent csi[na] scintillation detector to constrain sub-gev leptophobic dark matter models. this detector was built to observe low-energy nuclear recoils from coherent elastic neutrino-nucleus scattering. these capabilities enable searches for dark matter particles produced at the spallation neutron source mediated by a vector portal particle with masses between 2 and 400 mev/c$^2$. no evidence for dark matter is observed and a limit on the mediator coupling to quarks is placed. this constraint improves upon previous results by two orders of magnitude. this newly explored parameter space probes the region where the dark matter relic abundance is explained by leptophobic dark matter when the mediator mass is roughly twice the dark matter mass. coherent sets the best constraint on leptophobic dark matter at these masses. | a coherent constraint on leptophobic dark matter using csi data |
the nature of the high-lying final levels of the 96ygsβ decay, one of the three most important contributors to the high-energy reactor antineutrino spectrum, has been investigated in high-resolution γ-ray spectroscopy following the β decay as well as in a campaign of inelastic photon scattering experiments. the comprehensive approach establishes 1- levels associated with the pygmy dipole resonance as high-lying final levels in the β decay. branching ratios extracted from β decay complement photon scattering and allow the absolute e1 excitation strength to be determined for levels populated in both reactions. the combined data represents a comprehensive approach to the wavefunction of the 1- levels below the qβ value, which are investigated in the quasiparticle phonon model. the calculations reveal that the components populated in β decay contribute only with small amplitudes to the complex wavefunction of these 1- levels. a comparison of the β decay results to data from total absorption γ-ray spectroscopy demonstrates a good agreement between both measurements. | structure of high-lying levels populated in the 96y →96zr β decay |
we recently reported on the radio-frequency attenuation length of cold polar ice at summit station, greenland, based on bistatic radar measurements of radio-frequency bedrock echo strengths taken during the summer of 2021. those data also include echoes attributed to stratified impurities or dielectric discontinuities within the ice sheet (layers), which allow studies of a) estimation of the relative contribution of coherent (discrete layers, e.g.) vs. incoherent (bulk volumetric, e.g.) scattering, b) the magnitude of internal layer reflection coefficients, c) limits on the azimuthal asymmetry of reflections (birefringence), and d) limits on signal dispersion in-ice over a bandwidth of ~100 mhz. we find that i) after averaging 10000 echo triggers, reflected signal observable over the thermal floor (to depths of approximately 1500 m) are consistent with being entirely coherent, ii) internal layer reflection coefficients are measured at approximately -60 to -70 db, iii) birefringent effects for vertically propagating signals are smaller by an order of magnitude relative to comparable studies performed at south pole, and iv) within our experimental limits, glacial ice is non-dispersive over the frequency band relevant for neutrino detection experiments. | radiofrequency ice dielectric measurements at summit station, greenland |
impact of the in-medium modified nucleon weak and electromagnetic form factors on the neutrino mean free path in dense matter is studied by considering both the weak and electromagnetic interactions of neutrinos with the constituents of the matter. a relativistic mean field model and the quark-meson coupling model are respectively adopted for the in-medium effective nucleon mass and nucleon form factors. we find that the cross sections of neutrino scattering in cold nuclear medium decrease when the in-medium modifications of the nucleon weak and electromagnetic form factors are taken into account. this reduction results in the enhancement of the neutrino mean free path, in particular at the baryon density of around a few times of the normal nuclear matter density. the enhancement of the neutrino mean free path is estimated to be about 10%-40% compared with the values obtained without the medium modifications of the nucleon form factors, and the enhancement is expected to accelerate the cooling of neutron stars. | impact of medium modifications of the nucleon weak and electromagnetic form factors on the neutrino mean free path in dense matter |
a connection between the neutrino and an exotic fermion is described in the general neutrino model. in this model the neutrinos can convert into the new fermion and thus the interaction leads to novel recoil spectrum in the neutrino scattering experiments. we study the general neutrino interaction by evaluating both the tree-level and loop-level contributions to the coherent elastic neutrino-nucleus scattering. we illustrate the scattering by taking the framework of a simplified neutrino model with a dirac fermion χ and a spin-0 mediator. for the cp phase in the quark sector being 0 and π/2, the detection processes are dominated by the tree-level and loop-level contribution, respectively. we investigate the constraints on the couplings between the mediator and the new particle χ or the quarks by fitting to the coherent data. the parameter space with mχ larger than the maximal energy of incoming neutrinos can be also constrained by including the loop-level contribution. | loop effect in the coherent neutrino-nucleus scattering |
the light yield of an undoped csi crystal at about 77 kelvin was measured to be 33.5 ±0.7 photo-electrons (pe) per kev electron-equivalent (kevee) in the energy range of [13, 60] kevee using x and γ -rays from an 241am radioactive source. based on this experimental result, the performance of 10 kg cryogenic inorganic scintillating crystals coupled to sipm arrays to probe non-standard neutrino interactions through the detection of coherent elastic neutrino-nucleus scatterings at the spallation neutron source, oak ridge national laboratory, was examined in detail. | light yield of cold undoped csi crystal down to 13 kev and the application of such crystals in neutrino detection |
we present the fully up-to-date calculation of the γ z -box correction which needs to be taken into account to determine the weak mixing angle at low energies from parity-violating electron proton scattering. we make use of neutrino and antineutrino inclusive scattering data to predict the parity-violating structure function f3γ z by isospin symmetry. our new analysis confirms previous results for the axial contribution to the γ z -box graph and reduces the uncertainty by a factor of 2. in addition, we note that the presence of parity-violating photon-hadron interactions induces an additional contribution via f3γ γ. using experimental and theoretical constraints on the nucleon anapole moment we are able to estimate the uncertainty associated with this contribution. we point out that future measurements are expected to significantly reduce this latter uncertainty. | reduced uncertainty of the axial γ z -box diagram correction to the proton's weak charge |
we have applied a microscopic model for single photon emission in neutral current interactions on nucleons and nuclei to determine the number and distributions of such events at the super-kamiokande detector, for the flux and beam exposure of the t2k experiment in neutrino mode. these reactions represent an effectively irreducible background in electron-(anti)neutrino appearance measurements aimed at a precise measurement of mixing angle θ13 and the c p violating phase. we have obtained a total number of photon events that is twice as large as the one from the neut event generator (version 5.1.4.2) used in the analysis of t2k data. detailed comparisons of energy and angular distributions for the νμ and ν¯μ fluxes have also been performed. | photon emission in neutral current interactions at the t2k experiment |
we have studied the strangeness-changing antineutrino-induced reactions ν¯lp →l+ϕ b , with ϕ b =k-p , k¯0n , π0λ , π0σ0 , η λ , η σ0 , π+σ- , π-σ+ , k+ξ- , and k0ξ0 , using a chiral unitary approach. these ten coupled channels are allowed to interact strongly, using a kernel derived from the chiral lagrangians. this interaction generates two λ (1405 ) poles, leading to a clear single peak in the π σ invariant mass distributions. at backward scattering angles in the center-of-mass frame, ν¯μp →μ+π0σ0 is dominated by the λ (1405 ) state at around 1420 mev while the lighter state becomes relevant as the angle decreases, leading to an asymmetric line shape. in addition, there are substantial differences in the shape of π σ invariant mass distributions for the three charge channels. if observed, these differences would provide valuable information on a claimed isospin i =1 , strangeness s =-1 baryonic state around 1400 mev. integrated cross sections have been obtained for the π σ and k ¯n channels and the impact of unitarization in the results has been investigated. the number of events with λ (1405 ) excitation in ν¯μp collisions in the recent antineutrino run at the main injector experiment for ν -a (minerνa) has also been obtained. we find that this reaction channel is relevant enough to be investigated experimentally and to be taken into account in the simulation models of future experiments with antineutrino beams. | antineutrino induced λ (1405 ) production off the proton |
we study the implication of j /ψ decay into invisible particles for light sterile neutrino and sub-gev dark matter (dm). the low-energy effective field theories (efts) are used for the description of general neutrino interactions and the dirac fermion dm coupled to charm quark. for j /ψ →γ +invisible, we perform the likelihood fits for the individual neutrino and dm operators with distinct lorentz structures and photon spectra. the limits on the decay branching fractions are obtained for different neutrino or dm scenarios and then converted to the lower bounds on the new energy scales. the most stringent bounds on the energy scale in neutrino and dm efts are 12.8 gev and 11.6 gev, respectively. the purely invisible decay j /ψ →invisible provides complementary constraints on the effective operators. the relevant bound on the energy scale is above 100 gev for the dipole operators. we also evaluate the limit on the dm-nucleon scattering cross section converted from j /ψ data. the data of j /ψ invisible decays are sensitive to the light dm mass range where the dm direct detection experiments cannot probe yet. the future super tau charm factory after one year run can push the limits down by two orders of magnitude. | implication of j /ψ →(γ +)invisible for the effective field theories of neutrino and dark matter |
a search for a heavy resonance decaying into a top quark and a w boson in proton-proton collisions at √{s } = 13 tev is presented. the data analyzed were recorded with the cms detector at the lhc and correspond to an integrated luminosity of 138 fb-1. the top quark is reconstructed as a single jet and the w boson, from its decay into an electron or muon and the corresponding neutrino. a top quark tagging technique based on jet clustering with a variable distance parameter and simultaneous jet grooming is used to identify jets from the collimated top quark decay. the results are interpreted in the context of two benchmark models, where the heavy resonance is either an excited bottom quark b∗ or a vector-like quark b. a statistical combination with an earlier search by the cms collaboration in the all-hadronic final state is performed to place upper cross section limits on these two models. the new analysis extends the lower range of resonance mass probed from 1.4 down to 0.7 tev. for left-handed, right-handed, and vector-like couplings, b∗ masses up to 3.0, 3.0, and 3.2 tev are excluded at 95% confidence level, respectively. the observed upper limits represent the most stringent constraints on the b∗ model to date. | search for a heavy resonance decaying into a top quark and a w boson in the lepton+jets final state at √{s } = 13 tev |
new results for the exclusive and quasifree cross sections off neutrons bound in deuterium γvn (p ) →p π−(p ) are presented over a wide final state hadron angle range with a kinematic coverage of the invariant mass (w ) up to 1.825 gev and the four-momentum transfer squared (q2) from 0.4 to 1.0 gev2. the exclusive structure functions were extracted and their legendre moments were obtained. final-state-interaction contributions have been kinematically separated from the extracted quasifree cross sections off bound neutrons solely based on the analysis of the experimental data. these new results will serve as long-awaited input for phenomenological analyses to extract the q2 evolution of previously unavailable n →n* electroexcitation amplitudes and to improve state-of-the-art models of neutrino scattering off nuclei by augmenting the already available results from free protons. | exclusive π− electroproduction off the neutron in deuterium in the resonance region |
the theoretical results for the total cross sections and polarization components of the τ+ lepton produced in the charged current induced |δ s |=1 quasielastic ν¯τ-n scattering leading to hyperons (λ , σ ) have been presented assuming t invariance. the theoretical uncertainties arising due to the use of different vector, axial-vector, and pseudoscalar form factors as well as the effect of su(3) symmetry breaking have been studied. we have also presented, for the first time, a comparison of the total cross sections for the production of e , μ , τ leptons to facilitate the implications of lepton flavor universality in the |δ s |=1 quasielastic reactions induced by the antineutrinos of all flavors i.e., νl ; l =e , μ , τ . | hyperon production in quasielastic ν¯τ-nucleon scattering |
a search for heavy resonances, decaying into the standard model vector bosons and the standard model higgs boson, is presented. the final states considered contain a b quark-antiquark pair from the decay of the higgs boson, along with electrons and muons and missing transverse momentum, due to undetected neutrinos, from the decay of the vector bosons. the mass spectra are used to search for a localized excess consistent with a resonant particle. the data sample corresponds to an integrated luminosity of 35.9 fb-1 collected in 2016 by the cms experiment at the cern lhc from proton-proton collisions at a center-of-mass energy of 13 tev. the data are found to be consistent with background expectations. exclusion limits are set in the context of spin-0 two higgs doublet models, some of which include the presence of dark matter. in the spin-1 heavy vector triplet framework, mass-degenerate w' and z' resonances with dominant couplings to the standard model gauge bosons are excluded below a mass of 2.9 tev at 95% confidence level. | search for heavy resonances decaying into a vector boson and a higgs boson in final states with charged leptons, neutrinos and b quarks at √{s}=13 tev |
when neutrinos are propagating in ordinary matter, their coherent forward scattering off background particles results in the so-called mikheyev-smirnov-wolfenstein (msw) matter potential, which plays an important role in neutrino flavor conversions. in this paper, we present a complete one-loop calculation of the msw matter potential in the standard model. first, we carry out the one-loop renormalization of the standard model in the on-shell scheme, where the electromagnetic fine-structure constant α , the weak gauge-boson masses mw and mz , the higgs-boson mass mh and the fermion masses mf are chosen as input parameters. then, the finite corrections to the scattering amplitudes of neutrinos with the electrons and quarks are calculated, and the one-loop msw matter potentials are derived. adopting the latest values of all physical parameters, we find that the relative size of one-loop correction to the charged-current matter potential of electron-type neutrinos or antineutrinos turns out to be 6%, whereas that to the neutral-current matter potential of all-flavor neutrinos or antineutrinos can be as large as 8%. the calculations are also performed in the ms ¯ scheme and compared with previous results in the literature. | mikheyev-smirnov-wolfenstein matter potential at the one-loop level in the standard model |
we review the physics of coherent elastic neutrino-nucleus scattering and the results and perspectives for the measurements of the radius of the neutron distribution of the nucleus, of the weak mixing angle, and of new neutrino interactions due to physics beyond the standard model. | a view of coherent elastic neutrino-nucleus scattering |
a search for high-mass dimuon resonance production in association with one or more b quark jets is presented. the study uses proton-proton collision data collected with the cms detector at the lhc corresponding to an integrated luminosity of 138 fb−1 at a center-of-mass energy of 13 tev. model-independent limits are derived on the number of signal events with exactly one or more than one b quark jet. results are also interpreted in a lepton-flavor-universal model with z' boson couplings to a bb quark pair (gb), an sb quark pair (gbδbs), and any same-flavor charged lepton (gℓ) or neutrino pair (gν), with |gν| = |gℓ|. for a z' boson with a mass mz' = 350 gev (2 tev) and |δbs| < 0.25, the majority of the parameter space with 0.0057 < |gℓ| < 0.35 (0.25 < |gℓ| < 0.43) and 0.0079 < |gb| < 0.46 (0.34 < |gb| < 0.57) is excluded at 95% confidence level. finally, constraints are set on a z' model with parameters consistent with low-energy b → sℓℓ measurements. in this scenario, most of the allowed parameter space is excluded for a z' boson with 350 < mz' < 500 gev, while the constraints are less stringent for higher mz' hypotheses. this is the first dedicated search at the lhc for a high-mass dimuon resonance produced in association with multiple b quark jets, and the constraints obtained on models with this signature are the most stringent to date. | search for a high-mass dimuon resonance produced in association with b quark jets at √{s } = 13 tev |
we investigate the impact of the new measurement of the antineutrino-proton scattering cross section from the minerva collaboration on generalized parton distributions (gpds), particularly the polarized gpds denoted as h∼ q . to achieve this, we perform some qcd analyses of the minerva data, in addition to all available data of the proton's axial form factors. we demonstrate that minerva data lead to consistent results with other related experimental data, confirming the universality of gpds. our results indicate that minerva data can impose new constraints on gpds, particularly on h∼ q . our predictions for the proton's axial charge radius, wacs cross section, and axial form factor show good consistency with those of other studies and measurements. this leads us to conclude that the result of a more comprehensive analysis, considering all related experimental data, is not only reasonable but also more reliable, even in light of existing tensions among the data. the present study can be considered as a guideline for performing a new and comprehensive qcd global analysis of gpds including the minerva measurements like that presented in hashamipour et al. [generalized parton distributions at zero skewness, phys. rev. d 107, 096005 (2023)., 10.1103/physrevd.107.096005]. | impact of recent minerva measurement of the antineutrino-proton scattering cross section on the generalized parton distributions |
a unique characteristic of exponentially growing scattering amplitude arises in an anomalous abelian effective field theory when an extremely light dirac neutrino mass is introduced to break the symmetry. we show that the low energy effective lagrangian can be made explicitly gauge invariant with the help of a nonlinear representation of the goldstone or stueckelberg field. we study the peculiar feature of exponential growth in the ultra-high-energy neutrino-nucleon inelastic scattering. it is found that the inelastic scattering cross section is highly sensitive to the ratio of gauge coupling to the gauge boson mass, gx /mx. when the icecube measurement of ultra-high-energy neutrinos, which is consistent with the standard model prediction up to eν ∼ 6 pev, is taken into account, the inferred constraint on gx /mx is more severe than that obtained from the events of mono-lepton+missing transverse energy at the lhc. a muon collider with a collision energy of 10 tev can be a good environment other than hadron colliders to probe the novel effect. | ultra-high-energy neutrino scattering in an anomalous u(1) effective field theory |
we investigate neutrino magnetic moment, triplet scalar dark matter in a type-ii radiative seesaw scenario. with three vector-like fermion doublets and two scalar triplets, we provide a loop level setup for the electromagnetic vertex of neutrinos. all the scalar multiplet components constitute the total dark matter abundance of the universe and also their scattering cross section with detector lie below the experimental upper limit. using the consistent parameter space in dark matter domain, we obtain light neutrino mass in sub-ev scale and also magnetic moment in the desired range. we further derive the constraints on neutrino transition magnetic moments, consistent with xenonnt limit. | correlating neutrino magnetic moment and scalar triplet dark matter to enlighten xenonnt bounds in a type-ii model |
res-nova is a newly proposed experiment for the detection of neutrinos from astrophysical sources, mainly supernovae, using an array of cryogenic detectors made of pbwo$_4$ crystals produced from archaeological pb. this unconventional material, characterized by intrinsic high radiopurity, enables to achieve low-background levels in the region of interest for the neutrino detection via coherent elastic neutrino-nucleus scattering (ce$\nu$ns). this signal lies at the detector energy threshold, o(1 kev), and it is expected to be hidden by naturally occurring radioactive contaminants of the crystal absorber. here, we present the results of a radiopurity assay on a 0.84 kg pbwo$_4$ crystal produced from archaeological pb operated as a cryogenic detector. the crystal internal radioactive contaminations are: $^{232}$th $<$40 $\mu$bq/kg, $^{238}$u $<$30 $\mu$bq/kg, $^{226}$ra 1.3 mbq/kg and $^{210}$pb 22.5 mbq/kg. we present also a background projection for the final experiment and possible mitigation strategies for further background suppression. the achieved results demonstrate the feasibility of realizing this new class of detectors. | radiopurity of a kg-scale pbwo$_4$ cryogenic detector produced from archaeological pb for the res-nova experiment |
in liquid argon tpcs for dark matter search and neutrino detection experiments, primary scintillation light is used as a prompt signal of particle scattering, being intensively produced in the vacuum ultraviolet (vuv) due to excimer emission mechanism. on the other hand, there were indications on the production of visible-light emission in liquid argon, albeit at a much lower intensity, the origin of which is still not clear. the closely related issue is visible-light emission in liquid argon doped with methane, the interest in which is due to the possible use in neutron veto detectors for those experiments. in this work we study in detail the properties of such light emission in pure liquid argon and its mixtures with methane. in particular, the absolute photon yield of visible-light emission in pure liquid argon was measured to be about 200 and 90 photon/mev for x-rays and alpha particles respectively. in liquid argon doped with methane the photon yield dropped down significantly, by about an order of magnitude at a methane molar content varying from 0.01 to 1%, and then almost did not change when further increasing the methane content up to 10%. | study of visible-light emission in pure and methane-doped liquid argon |
in neutrino interactions with nucleons and nuclei, shallow inelastic scattering (sis) refers to processes, dominated by non-resonant contributions, in the kinematic region where $q^2$ is small and the invariant mass of the hadronic system, $w$, is above the pion production threshold. the extremely rich science of this complex region, poorly understood both theoretically and experimentally, encompasses the transition from interactions described in terms of hadronic degrees of freedom to interactions with quarks and gluons described by perturbative qcd. since a large fraction of events in nova and dune, and in atmospheric neutrino measurements such as icecube-upgrade, km3net, super- and hyper-kamiokande, are from this sis region, there is a definite need to improve our knowledge of this physics. this loi summarizes the current understandings of the sis physics and a series of proposals for the path to forward. | snowmass 2021 loi: neutrino-induced shallow- and deep-inelastic scattering |
we discuss how to calculate cross sections as well as rapidity, transverse momentum and energy distributions of ντ and ν¯τ produced from the direct ds±→ντ/ν¯τ and chain ds±→τ+/τ-→ντ/ν¯τ decays in p+96 mo scattering with proton beam elab = 400 gev i.e. at √{s}nn = 27.4 gev. the τ decays are simulated with the help of the tauola code and include multiple decay channels of τ in amounts proportional to their branching ratios. in our calculations we include ds± from charm fragmentation c →ds+ and c ¯→ds- as well as those from subleading fragmentation of strange quarks/antiquarks s →ds- and s ¯→ds+. the s ≠s ¯ asymmetry of the strange quark content of proton is included. the different contributions to ds+ and ντ/ν¯τ are shown explicitly. we discuss and quantify a not discussed so far effect of asymmetries for production of ντ and ν¯τ caused by subleading fragmentation mechanism and discuss related uncertainties. a potential measurement of the asymmetry is discussed. estimates of a number of observed ντ/ν¯τ in the ντ/ν¯τ +208pb reaction, with 2m long target are given with the help of the nuwro program. we refer also to the production of the high-energy (anti)neutrinos in the atmosphere. | production asymmetry of ντ neutrinos and ν¯τ antineutrinos from a fixed target experiment ship |
we present self-destructing dark matter (sddm), a new class of dark matter models which are detectable in large neutrino detectors. in this class of models, a component of dark matter can transition from a long-lived state to a short-lived one by scattering off of a nucleus or an electron in the earth. the short-lived state then decays to standard model particles, generating a dark matter signal with a visible energy of order the dark matter mass rather than just its recoil. this leads to striking signals in large detectors with high energy thresholds. we present a few examples of models which exhibit self destruction, all inspired by bound state dynamics in the standard model. the models under consideration exhibit a rich phenomenology, possibly featuring events with one, two, or even three lepton pairs, each with a fixed invariant mass and a fixed energy, as well as non-trivial directional distributions. this motivates dedicated searches for dark matter in large underground detectors such as super-k, borexino, sno+, and dune. | self-destructing dark matter |
experiments seeking to detect rare event interactions such as dark matter or coherent elastic neutrino nucleus scattering are striving for large mass detectors with very low detection threshold. using neganov-luke phonon amplification effect, the cryogenic dark matter search (cdms) experiment is reaching unprecedented rms resolutions of ∼14 evee. cdmslite is currently the most sensitive experiment to wimps of mass ∼5 gev/c2 but is limited in achieving higher phonon gains due to an early onset of leakage current into ge crystals. the contact interface geometry is particularly weak for blocking hole injection from the metal, and thus a new design is demonstrated that allows high voltage bias via vacuum separated electrode. with an increased bias voltage and a×2 luke phonon gain, world best rms resolution of sigma ∼7 evee for 0.25 kg (d=75 mm, h=1 cm) ge detectors was achieved. since the leakage current is a function of the field and the phonon gain is a function of the applied voltage, appropriately robust interface blocking material combined with thicker substrate (25 mm) will reach a resolution of ∼2.8 evee. in order to achieve better resolution of ∼ ev, we are investigating a layer of insulator between the phonon readout surface and the semiconductor crystals. | toward single electron resolution phonon mediated ionization detectors |
the beam dump experiment (bdx) aims to investigate the existence of light dark matter (dm) particles in the mev-gev mass range, theoretically well motivated but still barely explored. in this mass range bdx will be sensitive to large regions of dm parameter space, exceeding the discovery potential of existing and planned experiments by up to two orders of magnitude. bdx is an e--beam thick-target experiment, expected to run at jefferson lab, downstream of the hall a beam dump, receiving up to 1022 electron-on-target (eot). the detector is made of two main components: an electromagnetic calorimeter (ecal), and a veto detector used to suppress the background. bdx will be sensitive to elastic and inelastic dm-electron scattering at the level of 10 counts per year, reaching the limit of the irreducible background due to beam-produced neutrinos. the expected signature of the dm interaction in the ecal is a gev electromagnetic shower paired with a null activity in the surrounding active veto counters. in order to evaluate the background contributions two approaches were used: the cosmogenic background was extrapolated from results obtained with a prototype running at infn-lns (italy), while the beam- related background was evaluated by geant4 monte carlo simulations. this paper describes the experimental setup and the results of the background studies along with the status and prospectives of the experiment. | light dark matter search in a beam-dump experiment: bdx at jefferson lab |
the electron (anti-)neutrino component of the t2k neutrino beam constitutes the largest background in the measurement of electron (anti-)neutrino appearance at the far detector. the electron neutrino scattering is measured directly with the t2k off-axis near detector, nd280. the selection of the electron (anti-)neutrino events in the plastic scintillator target from both neutrino and anti-neutrino mode beams is discussed in this paper. the flux integrated single differential charged-current inclusive electron (anti-)neutrino cross-sections, $d\sigma/dp$ and $d\sigma/d\cos(\theta)$, and the total cross-sections in a limited phase-space in momentum and scattering angle ($p > 300$ mev/c and $\theta \leq 45^{\circ}$) are measured using a binned maximum likelihood fit and compared to the neutrino monte carlo generator predictions, resulting in good agreement. | measurement of the charged-current electron (anti-)neutrino inclusive cross-sections at the t2k off-axis near detector nd280 |
dual-phase xenon detectors lead the search for kev-scale nuclear recoil signals expected from the scattering of weakly interacting massive particle (wimp) dark matter, and can potentially be used to study the coherent nuclear scattering of mev-scale neutrinos. new capabilities of such experiments can be enabled by extending their nuclear recoil searches down to the lowest measurable energy. the response of the liquid xenon target medium to nuclear recoils, however, is not well characterized below a few kev, leading to large uncertainties in projected sensitivities. in this work, we report a new measurement of ionization signals from nuclear recoils in liquid xenon down to the lowest energy reported to date. at 0.3 kev, we find that the average recoil produces approximately one ionization electron; this is the first measurement of nuclear recoil signals at the single-ionization-electron level, approaching the physical limit of liquid xenon ionization detectors. we discuss the implications of these measurements on the physics reach of xenon detectors for nuclear-recoil-based wimp dark matter searches and the detection of coherent elastic neutrino-nucleus scattering. | low-energy physics reach of xenon detectors for nuclear-recoil-based dark matter and neutrino experiments |
the coherent collaboration has produced the first-ever observation, with a significance of 6.7sigma, of a process consistent with coherent, elastic neutrino-nucleus scattering (cenuns) as first predicted and described by d.z. freedman in 1974. physics of the cenuns process are presented along with its relationship to future measurements in the arenas of nuclear physics, fundamental particle physics, and astroparticle physics, where the newly-observed interaction presents a viable tool for investigations into numerous outstanding questions about the nature of the universe. to enable the cenuns observation with a 14.6-kg csi[na] detector, new measurements of the response of csi[na] to low-energy nuclear recoils, which is the only mechanism by which cenuns is detectable, were carried out at triangle universities nuclear laboratory; these measurements are detailed and an effective nuclear-recoil quenching factor of 8.78 +/- 1.66% is established for csi[na] in the recoil-energy range of 5-30 kev, based on new and literature data. following separate analyses of the cenuns-search data by groups at the university of chicago and the moscow engineering and physics institute, information from simulations, calculations, and ancillary measurements were used to inform statistical analyses of the collected data. based on input from the chicago analysis, the number of cenuns events expected from the standard model is 173 +/- 48; interpretation as a simple counting experiment finds 136 +/- 31 cenuns counts in the data, while a two-dimensional, profile likelihood fit yields 134 +/- 22 cenuns counts. details of the simulations, calculations, and supporting measurements are discussed, in addition to the statistical procedures. finally, potential improvements to the csi[na]-based cenuns measurement are presented along with future possibilities for coherent collaboration, including new cenuns detectors and measurement of the neutrino-induced neutron spallation process. | measurement of low-energy nuclear-recoil quenching factors in csi[na] and statistical analysis of the first observation of coherent, elastic neutrino-nucleus scattering |
in this paper we investigate impacts of non-standard neutrino interactions (nsis) to the limitations on the discovery potential of dark matter in direct detection experiments. new neutrino floors are derived taking into account current upper bounds on the effective couplings of various nsis. our study shows that the neutrino floors of the standard model neutral current interactions can be significantly changed in the presence of vector-current nsi and scalar-current nsi, and the neutrino floors can be raised up to about script o(20%) in the presence of pseudo-scalar-current nsi, and there are almost no impacts to the neutrino floors from the axial-vector nsi and the tensor nsi. we suggest combining the dark matter direct detection experiments with the coherent elastic neutrino nucleus scattering experiments to hunt for new physics behind the signal of nuclear recoil in the future. | direct detections of dark matter in the presence of non-standard neutrino interactions |
the largest uncertainties in estimating neutrino-nucleus interaction cross sections lie in the incomplete understanding of nuclear effects. a powerful tool to study nuclear effects is transverse kinematic imbalance. this paper presents the first detailed comparison of the predictions of multiple event generators for distributions associated with transverse kinematic imbalance for neutrino interactions on argon. predictions for muon neutrinos interacting with an argon target are obtained using four standard neutrino event generation tools (genie, nuwro, gibuu and neut). example opportunities for discrimination between nuclear models leveraging future measurements are highlighted. the predictions shown in this paper are motivated by studying muon neutrinos from the fermilab booster neutrino beam interacting at the location of the microboone liquid argon time projection chamber, but the methods directly apply to other accelerator-based liquid argon neutrino experiments such as sbnd, icarus and dune. | comparing generator predictions of transverse kinematic imbalance in neutrino-argon scattering |
measuring the polarization fractions of the w+w- scattering reveals the interactions of the higgs boson as well as new neutral states that are related to the standard model electroweak symmetry breaking. the dileptonic channel has a relatively lower background rate, but the kinematics of its final states cannot be fully reconstructed due to the presence of two neutrinos. we propose neural networks to establish maps between the distributions of measurable quantities and the distributions of the lepton angles in w boson rest frames. new physics contributions and collision energy can largely affect the kinematic properties of the w+w- scattering beside the lepton angles. to make the network applicable to processes with varying kinematics, the loss function is modified in two different ways. we show that the networks are promising in reproducing the lepton angle distributions, and the precision of the fitted polarization fractions obtained from network predictions is comparable to that obtained with the truth lepton angle. although the best-fit values of the polarization fractions do not change much after including the background uncertainty, the precision is substantially reduced. | polarization measurement for the dileptonic channel of w+w- scattering using generative adversarial network |
the coherent elastic neutrino-nucleus scattering (cevns) plays a crucial role at the final evolution of stars. the detection of it would be of importance in astroparticle physics. among all available neutrino sources, galactic supernovae give the highest neutrino flux in the mev range. among all liquid xenon dark matter experiments, xmass has the largest sensitive volume and light yield. the possibility to detect galactic supernova via the cevns-process on xenon nuclei in the current xmass detector was investigated. the total number of events integrated in about 18 s after the explosion of a supernova 10 kpc away from the earth was expected to be from 3.5 to 21.1, depending on the supernova model used to predict the neutrino flux, while the number of background events in the same time window was measured to be negligible. all lead to very high possibility to detect cevns experimentally for the first time utilizing the combination of galactic supernovae and the xmass detector. in case of a supernova explosion as close as betelgeuse, the total observable events can be more than ∼ 104, making it possible to distinguish different supernova models by examining the evolution of neutrino event rate in xmass. | detectability of galactic supernova neutrinos coherently scattered on xenon nuclei in xmass |
electroweak scattering of neutrinos with hadronic targets reveal the underlying structure of protons and neutrons. electroweak structure functions for nucleon targets are reviewed in the context of muon and tau neutrino and antineutrino scattering. quantum chromodynamic, target mass and quark mass corrections and the regimes where they are relevant are discussed. in future experiments in the large hadron collider forward region at cern, there are prospects for future measurements for neutrino and antineutrino energies in the 100's of gev to tev energy regime with a large flux of ντ+ν¯τ as well as the electron and muon flavors. at lower energies, dune will probe structure functions at the boundary of perturbative and nonperturbative regimes. | evolution of the electroweak structure functions of nucleons |
neutrino scattering experiments have been exploring the structure of the nucleon with deep-inelastic scattering for over 50 years. although hints of nucleon structure were available using cern's first neutrino beam in the 1960s, the study actually started quantitatively in the early 1970s with the gargamelle heavy liquid bubble chamber that produced first neutrino confirmation of scaling. this study of nucleon structure continued with both bubble chambers and more massive electronic detectors that, with higher energy neutrino beams and q2 reach, examined the breaking of this scaling while testing quantum chromodynamics. a significant factor when including neutrino explorations of nucleon structure in the overall picture is that to gather significant statistics, neutrino experiments have had to use heavier nuclear targets. it has been experimentally demonstrated that the structure of the nucleon in the nuclear environment is indeed different than the free nucleon structure. understanding this modified structure has played an important part in the experimental and theoretical exploration of nucleon structure by neutrinos and is one of the important goals of the on-going minerva experiment at fermilab. | from gargamelle to minerva: exploring the structure of the nucleon with neutrinos |
the neut intranuclear cascade model is described and fit to a large body of \pipm--nucleus scattering data. methods are developed to deal with deficiencies in the available historical data, and robust uncertainty estimates are produced. the results are compared to a variety of simulation packages, and the data itself. this work provides a method for tuning final state interaction models, which are of particular interest to neutrino experiments that operate in the few-gev energy region, and provides results which can be used directly by the t2k and super-kamiokande collaborations, for whom neut is the primary simulation package. | using world charged pion--nucleus scattering data to constrain an intranuclear cascade model |
the excitation of atomic nuclei via magnetic dipole transitions is closely related to the inelastic neutral-current neutrino-nucleus (nc-ν a ) scattering process due to the similarity of the transition operators. nc-ν a -scattering serves for the detection of supernova neutrinos and poses a significant source of background in modern liquid-argon based high-energy neutrino detection experiments. to enable tests of the reliability of predictions for neutrino-nucleus scattering, the magnetic dipole response of 40ar below 7.7 mev was characterized in a nuclear resonance fluorescence experiment using quasimonoenergetic γ -ray beams. the linear polarization of the beams allowed for assignments of electric or magnetic character to previously known dipole excitations. a total magnetic dipole strength of 0 .36-0.05+0.04μn2 was identified in the energy range of the present experiment. combined with data from previous measurements, the full magnetic dipole strength of 40ar below the neutron separation threshold was investigated. due to the low background in the energy range within the bandwidth of the γ -ray beams, the previous sensitivity limit was improved. a large-scale nuclear shell model calculation in the s d -f p space satisfactorily agrees with the data in terms of excitation energies and strengths of the observed 1+ states. | experimental m 1 response of 40ar as a benchmark for neutrino-nucleus scattering calculations |
this paper deals with the description of weak b-→d0,π0 and d-→k0,π0 transition form factors in both the space- and timelike momentum transfer regions, within a constituent-quark model. to this aim, neutrino-meson scattering and semileptonic weak decays are formulated within the framework of point-form relativistic quantum mechanics to end up with relativistic invariant process amplitudes from which meson transition currents and form factors are extracted in an unambiguous way. for spacelike momentum transfers, these form factors depend on the frame in which the w m m' vertex is considered. on physical grounds, such a frame dependence is expected from a pure valence-quark picture, since a complete, frame independent description of form factors is supposed to require valence as well as nonvalence contributions. nonvalence contributions, the most important being the z graphs, are, however, suppressed in the infinite-momentum frame (q2<0 ). on the other hand, they can play a significant role in the breit frame (q2<0 ) and in the direct decay calculation (q2>0 ), as a comparison with the infinite-momentum-frame form factors (analytically continued to q2>0 ) reveals. numerical results for the analytically continued infinite-momentum-frame form factors are found to agree very well with lattice data in the timelike momentum transfer region, and also, the experimental value for the slope of the fb→d + transition form factor at zero recoil is reproduced satisfactorily. furthermore, these predictions satisfy heavy-quark-symmetry constraints, and their q2 dependence is well approximated by a pole fit, reminiscent of a vector-meson-dominance-like decay mechanism. we discuss how such a decay mechanism can be accommodated within an extension of our constituent-quark model, by allowing for a nonvalence component in the meson wave functions, and we also address the question of wrong cluster properties inherent in the formulation of relativistic quantum mechanics employed in this article. | weak transition form factors of heavy-light pseudoscalar mesons for space- and timelike momentum transfers |
to describe low-energy (anti)neutrino fluxes in modern coherent elastic neutrino-nucleus scattering experiments as well as high-energy fluxes in precision-frontier projects such as the enhanced neutrino beams from kaon tagging (enubet) and the neutrinos from stored muons (nustorm), we evaluate (anti)neutrino energy spectra from radiative muon ($\mu^- \to e^- \bar{\nu}_e \nu_\mu (\gamma),~\mu^+ \to e^+ {\nu}_e \bar{\nu}_\mu (\gamma)$), pion $\pi_{\ell 2}$ ($\pi^- \to \mu^- \bar{\nu}_\mu (\gamma),~\pi^+ \to \mu^+ {\nu}_\mu (\gamma)$), and kaon $k_{\ell 2}$ ($k^- \to \mu^- \bar{\nu}_\mu (\gamma),~k^+ \to \mu^+ {\nu}_\mu (\gamma)$) decays. we compare detailed $\mathrm{o} \left( \alpha \right)$ distributions to the well-known tree-level results, investigate electron-mass corrections and provide energy spectra in analytical form. radiative corrections introduce continuous and divergent spectral components near the endpoint, on top of the monochromatic tree-level meson-decay spectra, which can change the flux-averaged cross section at $6\times 10^{-5}$ level for the scattering on $^{40}\mathrm{ar}$ nucleus with (anti)neutrinos from the pion decay at rest. radiative effects modify the expected (anti)neutrino fluxes from the muon decay around the peak region by $3-4$ permille, which is a precision goal for next-generation artificial neutrino sources. | radiative (anti)neutrino energy spectra from muon, pion, and kaon decays |
we study the online detection of gallium capture of monoenergetic neutrinos produced by a cr 51 radioactive source in a scintillation experiment. we find that cerium-doped gadolinium aluminum gallium garnet (ce:gagg) is a suitable scintillator which contains about 21% of gallium per weight and has a high mass density and light yield. combined with a highly efficient light detection system this allows tagging of the subsequent germanium decay and thus a clean distinction of gallium capture and elastic neutrino electron scattering events. with 1.5 tons of scintillator and 10 source runs of 3.4 mci, each, we obtain about 1700 gallium capture events with a purity of 90% and 680,000 neutrino electron scattering events, where the latter provide a precise normalization independent of any nuclear physics. we include a detailed discussion of backgrounds and find that this configuration would allow us to test the gallium anomaly at more than 5 σ in an independent way. | testing the gallium anomaly |
free nucleons propagating in water are known to produce γ rays, which form a background to the searches for diffuse supernova neutrinos and sterile neutrinos carried out with cherenkov detectors. as a consequence, the process of nucleon knockout induced by neutral-current quasielastic interactions of atmospheric (anti)neutrinos with oxygen needs to be under control at the quantitative level in the background simulations of ongoing and future experiments. in this paper, we provide a quantitative assessment of the uncertainty associated with the theoretical description of the nuclear cross sections, estimating it from the discrepancies between the predictions of different models. | estimate of the theoretical uncertainty of the cross sections for nucleon knockout in neutral-current neutrino-oxygen interactions |
the argoneut collaboration reports the first measurement of neutral current $\pi^{0}$ production in $\nu_{\mu}$-argon and $\bar{\nu}_{\mu}$-argon scattering. this measurement was performed using the argoneut liquid argon time projection chamber deployed at fermilab's numi neutrino beam with an exposure corresponding to 1.2$\times 10^{20}$ protons-on-target from the fermilab main injector and a mean energy for $\nu_{\mu}$ of 9.6~gev and for $\bar{\nu}_{\mu}$ of 3.6~gev. we compare the measured cross section and kinematic distributions to predictions from the genie and nuwro neutrino interaction event generators. | measurement of $\\nu_{\\mu}$ and $\\bar{\\nu}_{\\mu}$ neutral current $\\pi^{0} \\rightarrow \\gamma\\gamma$ production in the argoneut detector |
w bosons are produced at lhc from a forward-backward symmetric initial state. their decay to a charged lepton and a neutrino has a strong spin analysing power. the combination of these effects results in characteristic distributions of the pseudorapidity of the leptons decaying from w + and w - of different helicity. this observation may open the possibility to measure precisely the w + and w - rapidity distributions for the two transverse polarisation states of w bosons produced at small transverse momentum. | about the rapidity and helicity distributions of the w bosons produced at lhc |
res-nova is a newly proposed experiment for detecting neutrinos from astrophysical sources, mainly supernovae, using an array of cryogenic detectors made of pbwo4 crystals produced from archaeological pb. this unconventional material, characterized by intrinsic high radiopurity, enables low-background levels in the region of interest for the neutrino detection via coherent elastic neutrino-nucleus scattering (ceν ns). this signal lies at the detector energy threshold, o(1 kev), and it is expected to be hidden by naturally occurring radioactive contaminants of the crystal absorber. here, we present the results of a radiopurity assay on a 0.84 kg pbwo4 crystal produced from archaeological pb operated as a cryogenic detector. the crystal internal radioactive contaminations are: 232th <40 μ bq/kg, 238u <30 μ bq/kg, 226ra 1.3 mbq/kg and 210pb 22.5 mbq/kg. we also present a background projection for the final experiment and possible mitigation strategies for further background suppression. the achieved results demonstrate the feasibility of realizing this new class of detectors. | radiopurity of a kg-scale pbwo4 cryogenic detector produced from archaeological pb for the res-nova experiment |
a search is presented for a heavy resonance decaying into either a pair of z bosons or a z boson and a w boson (zz or wz), with a z boson decaying into a pair of neutrinos and the other boson decaying hadronically into two collimated quarks that are reconstructed as a highly energetic large-cone jet. the search is performed using the data collected with the cms detector at the cern lhc during 2016 in proton-proton collisions at a center-of-mass energy of 13 tev, corresponding to a total integrated luminosity of 35.9 fb-1. no excess is observed in data with regard to background expectations. results are interpreted in scenarios of physics beyond the standard model. limits at 95% confidence level on production cross sections are set at 0.9 fb (63 fb) for spin-1 w' bosons, included in the heavy vector triplet model, with mass 4.0 tev (1.0 tev), and at 0.5 fb (40 fb) for spin-2 bulk gravitons with mass 4.0 tev (1.0 tev). lower limits are set on the masses of w' bosons in the context of two versions of the heavy vector triplet model of 3.1tev and 3.4 tev, respectively. | search for a heavy resonance decaying into a z boson and a vector boson in the ν \\overline{ν}q\\overline{q} final state |
this work describes an investigation of electron scattering on molecular hydrogen and deuterium measured by "troitsk nu-mass" group. the results of this work are essential for further investigation of the tritium beta-spectrum in search for active and sterile neutrinos in "troitsk nu-mass" and katrin experiments as well as astrophysical problems. electrons were generated by the electron gun with a narrow emission spectrum (less than 0.3 ev) at the electron energies of 14, 17, 18.7, 19 and 25 kev. the relative resolution of spectrometer in these measurements was 8.3 × 10-5. | electron scattering on hydrogen and deuterium molecules at 14-25 kev by the "troitsk nu-mass" experiment |
low capacitance, large volume, high purity germanium (hpge) radiation detectors have been successfully employed in low-background physics experiments. however, some physical processes may not be detectable with existing detectors whose energy thresholds are limited by electronic noise. in this paper, methods are presented which can lower the electronic noise of these detectors. through ultra-low vibration mechanical cooling and wire bonding of a cmos charge sensitive preamplifier to a sub-pf p-type point contact hpge detector, we demonstrate electronic noise levels below 40 ev-fwhm. | ultra-low noise mechanically cooled germanium detector |
we calculate the coherent bremsstrahlung process ν +n →n +ν +γ off a nucleus n with the aim of revealing the neutrino mass via the photon endpoint spectrum. unfortunately, the large required power of a monochromatic neutrino source and/or large detector mass make it difficult to compete with traditional electron-spectrum endpoint measurements in nuclear β decay. our neutral-current process distinguishes between dirac and majorana neutrinos, but the change of the photon spectrum is of the order of mν/eν and thus very small, despite the final-state neutrino coming to rest at the photon endpoint. so the "dirac-majorana confusion theorem" remains intact even if eν≫mν applies only for the initial state. | neutrino mass from bremsstrahlung endpoint in coherent scattering on nuclei |
searches are presented for heavy gauge bosons decaying into a top and a bottom quark in data collected by the cms experiment at √{s}=13 tev that correspond to an integrated luminosity of 2.2 and 2.6 fb-1 in the leptonic and hadronic analyses, respectively. two final states are analyzed, one containing a single electron, or muon, and missing transverse momentum, and the other containing multiple jets and no electrons or muons. no evidence is found for a right-handed w' boson (w'r) and the combined analyses exclude at 95% confidence level w'r with masses below 2.4 tev if {m}_{w'r}≫ {m}_{νr} (mass of the right-handed neutrino), and below 2.6 tev if {m}_{w'r}<{m}_{νr} . the results provide the most stringent limits for right-handed w' bosons in the top and bottom quark decay channel. [figure not available: see fulltext.] | searches for w' bosons decaying to a top quark and a bottom quark in proton-proton collisions at 13 tev |
we investigate coherent-elastic neutrino-nucleus scattering ($ce\nu ns$) in 3-3-1 models for different values of $\beta$ in which $\beta$ is a parameter used to define the charge operator of the 331 models. we show that the number of events predicted by 331$\beta$ model is in agreement with the data given by coherent experiment. we evaluate the sensitivity of the mass of z' boson with 90% confidence level (cl) and find that $m_{z'}\geq 1.4 $tev for $\beta=-\sqrt{3}$ with 90% cl. we perform $\chi^2$ fit for liquid argon, germanium and nai detector subsystems, we obtain $m_{z'} \geq [2,3.1 ]$ tev with 90\% cl. our results indicate low-energy high-intensity measurements can provide a valuable probe, complementary to high energy collider searches at lhc and electroweak precision measurements. | coherent constraints on $z'$ in 331$\\beta$ model |
a light yield of 20.4 ± 0.8 photoelectrons/kev was achieved with an undoped csi crystal coupled directly to a photomultiplier tube at 77 kelvin. this is by far the largest yield in the world achieved with csi crystals. an energy threshold that is several times lower than the current dark matter experiments utilizing csi(tl) crystals may be achievable using this technique. together with novel csi crystal purification methods, the technique may be used to improve the sensitivities of dark matter and coherent elastic neutrino-nucleus scattering experiments. also measured were the scintillation light decay constants of the undoped csi crystal at both room temperature and 77 kelvin. the results are consistent with those in the literature. | light yield of an undoped csi crystal coupled directly to a photomultiplier tube at 77 kelvin |
particle detectors based on liquid argon (lar) have recently become recognized as an extremely attractive technology for the direct detection of dark matter as well as the measurement of coherent elastic neutrino-nucleus scattering (ce νns). the chinese argon group at institute of high energy physics has been studying the lar detector technology and a lar detector has been operating steadily. a program of using a dual phase lar detector to measure the ce νns at taishang nuclear power plant has been proposed and the r&d work is ongoing. considering the requirements of ultra-low radio-purity and high photon collection efficiency, sipms will be a good choice and will be used in the detector. in this proceeding, an introduction of the lar detector and the measurement results of sipm array at lar temperature will be presented. | the liquid argon detector and measurement of sipm array at liquid argon temperature |
we propose the use of isotopically highly enriched detectors for the precise study of coherent-elastic neutrino-nucleus scattering (cevns). cevns has been measured for the first time in csi and recently confirmed with a liquid argon detector. it is expected that several new experimental setups will measure this process with increasing accuracy. taking ge detectors as a working example, we demonstrate that a combination of different isotopes is an excellent option to do precision neutrino physics with cevns, test standard model predictions, and probe new physics scenarios. experiments based on this new idea can make simultaneous differential cevns measurements with detectors of different isotopic composition. particular combination of observables could be used to cancel systematic errors. while many applications are possible, we illustrate the idea with three examples: testing the dominant quadratic dependence on the number of neutrons, $n$, that is predicted by the theoretical models; constraining the average neutron root mean square (rms) radius; and testing the weak mixing angle and the sensitivity to new physics. in all three cases we find that the extra sensitivity provided by this method will potentially allow high-precision robust measurements with cevns and particularly, will resolve the characteristic degeneracies appearing in new physics scenarios. | novel approach for the study of coherent elastic neutrino-nucleus scattering |
nuclear reactors represent a promising neutrino source for ce ν ns (coherent-elastic neutrino-nucleus scattering) searches. however, reactor sites also come with high ambient neutron flux. neutron capture-induced nuclear recoils can create a spectrum that strongly overlaps the ce ν ns signal for recoils ≲100 ev for nuclear reactor measurements in silicon or germanium detectors. this background can be particularly critical for low-power research reactors providing a moderate neutrino flux. in this work we quantify the impact of this background and show that, for a measurement 10 m from a 1 mw reactor, the effective thermal neutron flux should be kept below ∼7 ×10-4 n /cm2 s so that the ce ν ns events can be measured at least at a 5 σ level with germanium detectors in 100 kg yr exposure time. this flux corresponds to 60% of the sea-level flux but needs to be achieved in a nominally high-flux (reactor) environment. improved detector resolution can help the measurements, but the thermal flux is the key parameter for the sensitivity of the experiment. for silicon detectors, the constraint is even stronger and thermal neutron fluxes must be near an order of magnitude lower. this constraint highlights the need of an effective thermal neutron mitigation strategy for future low threshold ce ν ns searches. in particular, the neutron capture-induced background can be efficiently reduced by active veto systems tagging the deexcitation gamma following the capture. | neutron capture-induced nuclear recoils as background for ce ν ns measurements at reactors |
we studied the performance of advanced semiconductor detectors to measure reactor antineutrino with the potential to drastically improve efficiency and lower existing thresholds of detectable incident-antineutrino-energy. recent developments, such as those by the mitchell institute neutrino experiment at reactor (miner) experiment at texas a&m university, in semiconductor technologies have enabled the ability to lower the coherent-elastic-neutrino-nucleus-scatter (ce νns) based detection threshold to nuclear recoil energies between 10-ev and 100-ev (dutta et al., 2016). existing detectors based on inverse beta decay (ibd) have a threshold of 1.806 mev (oralbaev et al., 2016). in this study, we calculated the ce νns response of semiconductor detectors to antineutrino flux from a 1-mw(th) triga reactor as a function of incident antineutrino energy. in the calculations, the reaction rates of detectors made of germanium and silicon are calculated for a 100-kg detector and placed 10 m from the core. no background radiation characterization and reduction were performed. first, the reactor antineutrino flux spectrum is obtained for the fuel composition specific to 1-mw(th) triga reactor without any thresholds. next, the standard model (sm) of physics is used to calculate the ce νns cross-section as a function of incident antineutrino energy. finally, the above two functions are convolved to provide the detector response for both, germanium and silicon detectors. the results show that germanium has a greater efficiency than silicon; however, it is shown that silicon is sensitive to lower antineutrino energies. it is found that a 100-ev nuclear recoil in germanium semiconductor detectors can be produced by a minimum incident energy of 1.84 mev antineutrinos, and in silicon by 1.14 mev antineutrinos. for the lower threshold, a 20-ev nuclear recoil in germanium semiconductors can be produced by a minimum incident energy of 0.82 mev antineutrinos and in si by 0.51 mev antineutrinos. lowering the detector response energy sensitivity equips us with newer techniques for nuclear fuel monitoring. | coherent elastic neutrino nucleus scatter response of semiconductor detectors to nuclear reactor antineutrinos |
scaling features of the nuclear electromagnetic response functions unveil aspects of nuclear dynamics that are crucial for interpreting neutrino- and electron-scattering data. in the large momentum-transfer regime, the nucleon-density response function defines a universal scaling function, which is independent of the nature of the probe. in this work, we analyze the nucleon-density response function of 12c, neglecting collective excitations. we employ particle and hole spectral functions obtained within two distinct many-body methods, both widely used to describe electroweak reactions in nuclei. we show that the two approaches provide compatible nucleon-density scaling functions that for large momentum transfers satisfy first-kind scaling. both methods yield scaling functions characterized by an asymmetric shape, although less pronounced than that of experimental scaling functions. this asymmetry, only mildly affected by final state interactions, is mostly due to nucleon-nucleon correlations, encoded in the continuum component of the hole spectral function. | scaling within the spectral function approach |
a measurement of ionization yields in noble-gas liquids is relevant to the energy calibration of nuclear recoil detectors for dark matter search and coherent neutrino-nucleus scattering experiments. in this work we further study the ionization yield of nuclear recoils in liquid ar, using a two-phase detector with an electroluminescence gap and dd neutron generator. the ionization yields of nuclear recoils in liquid ar were measured at 233 kev and electric fields of 0.56 and 0.62 kv/cm; their values amounted to 5.9 ± 0.8 and 7.4 ± 1 e-/kev, respectively. the characteristic dependences of the ionization yield on energy and electric field were determined, while comparing the results obtained to those at lower energies and higher fields. | measurement of the ionization yield of nuclear recoils in liquid argon using a two-phase detector with electroluminescence gap |
the magnificent ce$\nu$ns workshop (2018) was held november 2 & 3 of 2018 on the university of chicago campus and brought together theorists, phenomenologists, and experimentalists working in numerous areas but sharing a common interest in the process of coherent elastic neutrino-nucleus scattering (ce$\nu$ns). this is a collection of abstract-like summaries of the talks given at the meeting, including links to the slides presented. this document and the slides from the meeting provide an overview of the field and a snapshot of the robust ce$\nu$ns-related efforts both planned and underway. | proceedings of the magnificent ce$\\nu$ns workshop 2018 |
the pair annihilation of neutrinos (ν ν ¯→e+e-) can energize violent stellar explosions such as gamma ray bursts (grbs). the energy in this neutrino heating mechanism can be further enhanced by modifying the background spacetime over that of newtonian spacetime. however, one cannot attain the maximum grb energy (∼1052erg) in either the newtonian background or schwarzschild and hartle-thorne background. on the other hand, using modified gravity theories or the quintessence field as background geometries, the maximum grb energy can be reached. in this paper, we consider extending the standard model by an extra u (1) b -l gauge group and augmenting the energy deposition by neutrino pair annihilation process including contributions mediated by the z' gauge boson belonging to this model. from the observed energy of grb, we obtain constraints on u (1) b -l gauge coupling in different background spacetimes. we find that the bounds on gauge coupling in modified gravity theories and quintessence background are stronger than those coming from the neutrino-electron scattering experiments in the limit of small gauge boson masses. future grb observations with better accuracy can further strengthen these bounds. | energizing gamma ray bursts via z' mediated neutrino heating |
this paper describes a new experimental setup designed for the direct measurement of the rayleigh ratio and rayleigh scattering length for linear alkylbenzene, a solvent commonly used in liquid scintillator detectors for neutrino experiments. using the new approach, the perpendicularly polarized rayleigh ratio was determined to be (4.52 ± 0.28) × 10-6 m-1 sr-1 at 405 nm and (3.82 ± 0.24) × 10-6 m-1 sr-1 at 432 nm, and the corresponding rayleigh scattering length was lray = 22.9 ± 0.3(stat.) ± 1.7(sys.) m at 405 nm and lray = 27.0 ± 0.9(stat.) ± 1.8(sys.) m at 432 nm. these results are consistent with both previous results determined using other experimental strategies and theoretical predictions. | measurements of rayleigh ratios in linear alkylbenzene |
we examine a macroscopic system in a quantum superposition of two spatially separated localized states as a detector for a stream of weakly interacting relativistic particles. we do this using the explicit example of neutrinos with mev -scale energy scattering from a solid object via neutral-current neutrino-nucleus scattering. presuming the (anti)neutrino source to be a nuclear fission reactor, we utilize the estimated flux and coherent elastic neutrino-nucleus cross section to constrain the spatial separation δ x and describe the temporal evolution of the sensing system. particularly, we find that a potentially measurable relative phase between quantum superposed components is obtained for a single gram scale mass placed in a superposition of spatial components separated by 10−14 m under sufficient cooling and background suppression. | requirements on quantum superpositions of macro-objects for sensing neutrinos |
motivated by the first observation of coherent-elastic neutrino-nucleus scattering at the coherent experiment, we confront the neutrino dipole portal giving rise to the transition of the standard model neutrinos to sterile neutrinos with the recently released cenns 10 data from the liquid argon as well as the csi data of the coherent experiment. performing statistical analysis of those data, we show how the transition magnetic moment can be constrained for the range of the sterile neutrino mass between 10 kev and 40 mev. | probing neutrino dipole portal at coherent experiment |
the prospects of extracting new physics signals in coherent elastic neutrino–nucleus scattering (ceνns) processes are limited by the precision with which the underlying nuclear structure physics, embedded in the weak nuclear form factor, is known. we present calculations of charge and weak nuclear form factors and ceνns cross sections on 12c, 16o, 40ar, 56fe and 208pb nuclei. we obtain the proton and neutron densities, and charge and weak form factors by solving hartree–fock (hf) equations with a skyrme (ske2) nuclear potential. we validate our approach by comparing 208pb and 40ar charge form factor predictions with available elastic electron scattering data. since ceνns experiments at stopped-pion sources are also well suited to measure inelastic charged–current and neutral–current neutrino–nucleus cross sections, we also present calculations for these processes, incorporating a continuum random phase approximation (crpa) description on top of the hf–ske2 picture of the nucleus. providing both coherent as well as inelastic cross sections in a consistent framework, we aim at obtaining a reliable and detailed comparison of the strength of these processes in the energy region below 100 mev. furthermore, we attempt to gauge the level of theoretical uncertainty pertaining to the description of the 40ar form factor and ceνns cross sections by comparing relative differences between recent microscopic nuclear theory and widely-used phenomenological form factor predictions. future precision measurements of ceνns will potentially help in constraining these nuclear structure details that will in turn improve prospects of extracting new physics. | cross sections for coherent elastic and inelastic neutrino-nucleus scattering |
the conus experiment (coherent elastic neutrino nucleus scattering) aims at detecting coherent elastic neutrino nucleus scattering of reactor antineutrinos on germanium. the experiment will be set up at the commercial nuclear power plant of brokdorf, germany, at a distance of ∼17 m to the reactor core. the recoil of the nuclei hit by the antineutrinos is detected with four high-purity point contact germanium detectors with a very low threshold and an overall mass of about 4 kg. to suppress the background, the setup is equipped with a shell-like passive shield and an active muon veto system. the shield and the muon veto have successfully been tested at the shallow depth laboratory at max-planck-institut für kernphysik. monte carlo simulations have been performed to reproduce the prompt muon-induced background and to examine the induced neutron spectrum. currently, the low threshold germanium detectors are characterized and the experiment is prepared for commissioning. | a novel experiment for coherent elastic neutrino nucleus scattering: conus |
a search is presented for single production of a vector-like t quark with charge 2/3 e, in the decay channel featuring a top quark and a z boson, with the top quark decaying hadronically and the z boson decaying to neutrinos. the search uses data collected by the cms experiment in proton-proton collisions at a center-of-mass energy of 13 tev, corresponding to an integrated luminosity of 137 fb−1 recorded at the cern lhc in 2016-2018. the search is sensitive to a t quark mass between 0.6 and 1.8 tev with decay widths ranging from negligibly small up to 30% of the t quark mass. reconstruction strategies for the top quark are based on the degree of lorentz boosting of its final state. at 95% confidence level, the upper limit on the product of the cross section and branching fraction for a t quark of small decay width varies between 15 and 602 fb, depending on its mass. for a t quark with decay widths between 10 and 30% of its mass, this upper limit ranges between 16 and 836 fb. for most of the studied range, the results provide the best limits to date. this is the first search for single t quark production based on the full run 2 data set of the lhc. | search for single production of a vector-like t quark decaying to a top quark and a z boson in the final state with jets and missing transverse momentum at √{s } = 13 tev |
we show a relationship between elastic electron scattering observables and the elastic neutrino cross section that provides a straightforward determination of the latter from experimental data of the former and relates their uncertainties. an illustration of this procedure is presented using a hartree-fock mean field for the nuclear structure of a set of even-even nuclear targets, using the spectra of the neutrinos produced in pion decay at rest. we also analyze the prospects for measuring the incoherent axial contribution to the neutrino elastic scattering in odd targets. | unified approach to electron and neutrino elastic scattering off nuclei with an application to the study of the axial structure |
nuwro monte carlo generator of events is presented. it is a numerical environment containing all necessary ingredients to simulate interactions of neutrinos with nucleons and nuclei in realistic experimental situation in wide neutrino energy range. it can be used both for data analysis as well as studies of nuclear effects in neutrino interactions. the first results and functionalities of ewro - module of nuwro dedicated to electron nucleus scattering - are also presented. | nuwro monte carlo generator of neutrino interactions -- first electron scattering results |
large liquid argon detectors have become widely used in low rate experiments, including dark matter and neutrino research. however, the optical properties of liquid argon are not well understood at the large scales relevant for current and near-future detectors.the index of refraction of liquid argon at the scin- tillation wavelength has not been measured, and current rayleigh scattering length calculations disagree with measurements. furthermore, the rayleigh scattering length and index of refraction of solid argon and solid xenon at their scintillation wavelengths have not been previously measured or calculated. we introduce a new calculation using existing data in liquid and solid argon and xenon to extrapolate the optical properties at the scintillation wavelengths using the sellmeier dispersion relationship. | index of refraction, rayleigh scattering length, and sellmeier coefficients in solid and liquid argon and xenon |
in various extensions of the standard model of particle physics, and intriguingly even in the three-generation standard model without neutrino masses, neutrinos are allowed to have very tiny electric charges. after a review of the theoretical scenarios that allow the emergence of such charges, we discuss the existing observational limits and we derive new stringent direct upper bounds for the charges of the muon and tau neutrinos. we also point out a flavor-universal lower bound on neutrino charges which is obtained from the weak gravity conjecture, that is based on the hypothesis that gravity is the weakest force. we finally present a new flavor-universal upper bound on neutrino charges based on astrophysical observations of magnetars. | neutrino charge constraints from scattering to the weak gravity conjecture to neutron stars |
the status of the conus coherent reactor neutrino scattering experiment will be presented. | the status of conus |
neutrino-nucleus elastic scattering (ν ae l) provides a unique laboratory to study the quantum-mechanical (qm) coherency effects in electroweak interactions. the deviations of the cross sections from those of completely coherent systems can be quantitatively characterized through a coherency parameter α (q2) . the relations between α and the underlying nuclear physics in terms of nuclear form factors are derived. the dependence of cross section on α (q2) for the various neutrino sources is presented. the α (q2) values are evaluated from the measured data of the coherent csi and ar experiments. complete coherency and decoherency conditions are excluded by the csi data with p =0.004 at q2=3.1 ×103 mev2 and p =0.016 at q2=2.3 ×103 mev2 , respectively, verifying that both qm superpositions and nuclear many-body effects contribute to ν ae l interactions. | studies of quantum-mechanical coherency effects in neutrino-nucleus elastic scattering |
we report the first demonstration of a phonon-mediated silicon detector technology that provides a primary phonon measurement in a low-voltage region, and a simultaneous indirect measurement of the ionization signal through neganov-trofimov-luke amplification in a high voltage region, both in a monolithic crystal. we present characterization of charge and phonon transport between the two stages of the detector and the resulting background discrimination capability at low energies. this new detector technology has the potential to significantly enhance the sensitivity of dark matter and coherent neutrino scattering experiments beyond the capabilities of current technologies that have limited discrimination at low energies. | phonon-mediated high-voltage detector with background rejection for low-mass dark matter and reactor coherent neutrino scattering experiments |
the european spallation source (ess), currently finishing its construction, will soon provide the most intense neutron beams for multi-disciplinary science. at the same time, it will also produce a high-intensity neutrino flux with an energy suitable for precision measurements of coherent elastic neutrino-nucleus scattering. we describe some physics prospects, within and beyond the standard model, of employing innovative detector technologies to take the most out of this large flux. we show that, compared to current measurements, the ess will provide a much more precise understanding of neutrino and nuclear properties. | european spallation source: a future for coherent neutrino nucleus scattering |
properties of the propagation of scintillation light in liquid argon (lar), at λ ∼128 nm wavelength, have been experimentally investigated in a dedicated setup at cern. the speed of scintillation photons has been measured for the first time in this medium, refractive index and the rayleigh scattering are being studied as well. such measurement provides a key ingredient for the interpretation of data from the current and next generation large mass lar detectors as those dedicated to the search for rare events such as neutrinos or dark matter. furthermore the improvement on the understanding of the scintillation light propagation represent a benchmark for the multiple theoretical models and simulations for the next generation of detectors which are now based on still incomplete measurements and calculations. | experimental study of the propagation of scintillation light in liquid argon |
experiments seeking to detect rare event interactions such as dark matter or coherent elastic neutrino nucleus scattering are striving for large mass detectors with very low detection threshold. using neganov-luke phonon amplification effect, the cryogenic dark matter search (cdms) experiment is reaching unprecedented rms resolutions of ~ 14 ev$_{ee}$ . cdmslite is currently the most sensitive experiment to wimps of mass $\sim$5 gev/c$^{2}$ but is limited in achieving higher phonon gains due to an early onset of leakage current into ge crystals. the contact interface geometry is particularly weak for blocking hole injection from the metal, and thus a new design is demonstrated that allows high voltage bias via vacuum separated electrode. with an increased bias voltage and a $\times$ 2 luke phonon gain, world best rms resolution of sigma $\sim$7 ev$_{ee}$ for 0.25 kg (d=75 mm, h=1 cm) ge detectors was achieved. since the leakage current is a function of the field and the phonon gain is a function of the applied voltage, appropriately robust interface blocking material combined with thicker substrate (25 mm) will reach a resolution of $\sim$2.8 ev$_{ee}$. in order to achieve better resolution of $\sim$ ev, we are investigating a layer of insulator between the phonon readout surface and the semiconductor crystals. | toward single electron resolution phonon mediated ionization detectors |
turtle is a c library providing utilities allowing to navigate through a topography described by a digital elevation model (dem). the library has been primarily designed for the monte carlo transport of particles scattering over medium to long ranges, e.g. atmospheric muons. but, it can also efficiently handle ray tracing problems with very large dems (109 nodes or more), e.g. for neutrino simulations. the turtle library was built on an optimistic ray tracing algorithm, detailed in the present paper. this algorithm proceeds by trials and errors, approximating the topography within the modelling uncertainties of the dem data. this allows to traverse a topography in constant time, i.e. independently of the number of grid nodes, and with no added memory. detailed performance studies are provided by comparison to other ray tracing algorithms and as an application to muon transport in a monte carlo simulation. | turtle: a c library for an optimistic stepping through a topography |
the objective of this work is to determine if coherent-elastic-neutrino-nucleus scatter (ce νns) in natural germanium detectors can be used to detect antineutrinos from an ap1000-type fission reactor. in this work, we first modeled the ap1000 core using monte carlo n-particle transport code 6.2 (mcnp) to estimate the number of fissions from each fissile isotope in the core. next, the reactor antineutrino spectrum was computed using the summation method for fuel burnup from 10 to 60 gwd/mtu. it was found that with the increasing fuel burnup, as the 239pu inventory builds-up in the fuel and the 235u inventory depletes, the contributions from 239pu to fission is enhanced. thus, the antineutrino energy spectrum begins to skew more towards lower energies as seen by the quantification of third and fourth central moments. increased fuel burnup also results in greater antineutrino production. the detection setup assumes a 100-kg ce νns based natural germanium detector, which is placed outside the reactor containment, 25 m away from the core. the detector has a 100-ev nuclear recoil (nr) threshold and experiences a background level of 100 differential rate units (dru), per kg.kev.day, due to surrounding radiation interacting in the detector. we then computed the differential pulse height distribution responses for two 235u enrichment cases: 3.3-wt-% and 4.4-wt-% at burnup levels of 10, 20, 40, and 60 gwd/mtu. overall, the detection rate decreases when the burnup increases. this study indicates that germanium pulse height distribution end-point energies decrease with increasing fuel burnup and become less separable. thus, we note that the ce νns detector resolution would need to be higher for more burned fuel. a 16-ev nr is sufficient for distinguishing fresh fuel from that burned to 20 gwd/mtu. we also investigate the ability to detect a difference between burnups: 10 and 20 gwd/mtu, 10 and 40 gwd/mtu, 10 and 60 gwd/mtu, based on the integral detector counts after accounting for background and detection threshold. we determined that fuel burnup deviations can be detected with confidence much greater than 20%, as required by the iaea, for low likelihood events. for 3.3-wt-% 235u enrichment, the confidence levels to distinguish burnup between 10 and 20 gwd/mtu, 10 and 40 gwd/mtu, 10 and 60 gwd/mtu are 80.60%, 100%, and 100%, respectively. for 4.4-wt% 235u enrichment, but the same three burnup comparisons, the confidence levels decreased marginally to 65.52%, 100%, and 100%, respectively. | antineutrino detection for temporal monitoring of fuel burnup in a large nuclear reactor |
a search is reported for heavy resonances decaying into e μ final states in proton-proton collisions recorded by the cms experiment at the cern lhc at √{s}=13 tev, corresponding to an integrated luminosity of 35.9 fb-1. the search focuses on resonance masses above 200 gev. with no evidence found for physics beyond the standard model in the e μ mass spectrum, upper limits are set at 95% confidence level on the product of the cross section and branching fraction for this lepton-flavor violating signal. based on these results, resonant τ sneutrino production in r-parity violating supersymmetric models is excluded for masses below 1.7 tev, for couplings λ 132 = λ 231 = λ 311 ' = 0.01. heavy z' gauge bosons with lepton-flavor violating transitions are excluded for masses up to 4.4 tev. the e μ mass spectrum is also interpreted in terms of non-resonant contributions from quantum black-hole production in models with one to six extra spatial dimensions, and lower mass limits are found between 3.6 and 5.6 tev. in all interpretations used in this analysis, the results of this search improve previous limits by about 1 tev. these limits correspond to the most sensitive values obtained at colliders. | search for lepton-flavor violating decays of heavy resonances and quantum black holes to e μ final states in proton-proton collisions at √{s}=13 tev |
coherent elastic neutrino-nucleus scattering (cenuns) has the largest predicted cross-section of all low-energy neutrino couplings. however, as a neutral-current interaction, the only experimental signature of cenuns is a low-energy nuclear recoil, which made its detection challenging. cenuns remained unobserved for over four decades. i will describe the experiment that resulted in a cenuns observation at a 6.7-sigma confidence level, which was performed in the framework of the coherent collaboration. a low-background, 14.6-kg csi[na] scintillator was exposed to the neutrino emissions from the spallation neutron source at oak ridge national laboratory. characteristic cenuns signatures in energy and time, compatible with predictions from the standard model, were observed in high signal-to-background conditions. cenuns provides new opportunities to study neutrino properties, and enables the miniaturization of detectors. | first observation of coherent elastic neutrino-nucleus scattering |
the red-100 (russian emission detector) is being constructed for the experiment to search for elastic coherent neutrino scattering off atomic nuclei. this fundamental process was predicted several decades ago by the standard model of electroweak interactions but has not been discovered yet. the red-100 is a two-phase emission xenon detector containing ∼200 kg of the liquid xe (∼ 100 kg of that is in a fiducial volume). one of the possible sites to carry out the experiment is the sns (spallation neutron source) facility at oak ridge national laboratory, usa. sns is the world's most intense pulsed source of neutrinos and unique place to study neutrino properties. the energy spectrum of neutrinos produced at the sns extends up to ∼ 50 mev and satisfies coherence condition. these neutrinos give kinetic energies of xe recoils up to a few tens of kev where the response of nuclear recoils is well-known from neutron calibrations of dark matter detectors. the detector will be deployed in the basement under the experimental hall at a distance of ∼30 meters from the sns target. the expected signal and background (neutron and gamma) are estimated for this specific location. the detector details, current status and future plans are provided. | red-100 detector for the first observation of the elastic coherent neutrino scattering off xenon nuclei |
improvements in theoretical modeling of short range structures and phenomena, and comparisons with data, will require sustained collaboration between nuclear theorists and neutrino experimentalists. the extensive history of studying this area of nuclear physics in electron- and hadron-scattering experiments, coupled with the transformative capabilities of lartpcs to identify neutrinos, will provide a ripe opportunity for new discoveries that will further our understanding of the nucleus. | neutrino-nucleus interactions and the short-range structure of nuclei |
most antineutrinos produced in a nuclear reactor have energies below the inverse beta decay threshold and have not yet been detected. we show that a coherent elastic neutrino-nucleus scattering experiment with an ultralow energy threshold like nucleus can measure the flux of reactor neutrinos below 1.8 mev. using a regularized unfolding procedure, we find that a meaningful upper bound can be placed on the low energy flux, but the existence of the neutron capture component cannot be established. | how to measure the reactor neutrino flux below the inverse beta decay threshold with ce ν ns |
we report on empirical parametrizations of longitudinal and transverse nuclear excitation electromagnetic form factors in 12c and 16o. we extract the contribution of nuclear excitations to the normalized inelastic coulomb sum rule [sl(q ) ] as a function of momentum transfer q and find that it is significant (0.29 ±0.030 at q =0 .22 gev) . the total contributions of nuclear excitations to sl(q ) in 12c and 16o are found to be equal within uncertainties. since the cross sections for nuclear excitations are significant, the radiative tails from nuclear excitations should be included in precise calculations of radiative corrections to quasielastic electron scattering at low q and deep-inelastic electron scattering at large energy transfers ν . the parametrizations also serve as a benchmark in testing theoretical modeling of cross sections for excitation of nuclear states in electron and neutrino interactions on nuclear targets at low energies. | contribution of nuclear excitation electromagnetic form factors in 12c and 16o to the coulomb sum rule |
our moon is a natural giant direct-detection target for constraining dark matter. by considering the dark matter capture rate of the moon, we obtain some constraints of the spin-independent elastic scattering cross section of dark matter particles on nucleons σpsi using the background neutrino data. the upper limits of σpsi can be constrained to ∼10-38- 10-36 cm2 for certain "resonance dark matter mass" ranges. these stringent astrophysical constraints are complementary to the constraints obtained by the direct-detection experiments. | constraining the spin-independent elastic scattering cross section of dark matter using the moon as a detection target and the background neutrino data |
we present a determination of the neutral current weak axial charge gaz(0 )=-0.654 (3)stat(5)sys using the strange quark axial charge gas(0 ) calculated with lattice qcd. we then perform a phenomenological analysis, where we combine the strange quark electromagnetic form factor from lattice qcd with (anti)neutrino-nucleon scattering differential cross section from miniboone experiments in a momentum transfer region 0.24 ≲ q2 ≲ 0.71 gev2 to determine the neutral current weak axial form factor gaz(q2) in the range of 0 ≲ q2 ≤ 1 gev2. this yields a phenomenological value of gaz(0 ) = -0.687(89)stat(40)sys. the value of gaz(0 ) constrained by the lattice qcd calculation of gas(0 ), when compared to its phenomenological determination, provides a significant improvement in precision and accuracy and can be used to provide a constraint on the fit to gaz(q2) for q2> 0. this constrained fit leads to an unambiguous determination of (anti)neutrino-nucleon neutral current elastic scattering differential cross section near q2 = 0 and can play an important role in numerically isolating nuclear effects in this region. we show a consistent description of gaz(q2) obtained from the (anti)neutrino-nucleon scattering cross section data requires a nonzero contribution of the strange quark electromagnetic form factor. we demonstrate the robustness of our analysis by providing a post-diction of the bnl e734 experimental data. | weak neutral current axial form factor using (ν ¯)ν -nucleon scattering and lattice qcd inputs |
we propose the use of isotopically highly enriched detectors for the precise study of coherent-elastic neutrino-nucleus scattering (cevns). cevns has been measured for the first time in csi and recently confirmed with a liquid argon detector. it is expected that several new experimental setups will measure this process with increasing accuracy. taking ge detectors as a working example, we demonstrate that a combination of different isotopes is an excellent option to do precision neutrino physics with cevns, test standard model predictions, and probe new physics scenarios. experiments based on this new idea can make simultaneous differential cevns measurements with detectors of different isotopic composition. particular combination of observables could be used to cancel systematic errors. while many applications are possible, we illustrate the idea with three examples: testing the dominant quadratic dependence on the number of neutrons, n , that is predicted by the theoretical models; constraining the average neutron root mean square (rms) radius; and testing the weak mixing angle and the sensitivity to new physics. in all three cases we find that the extra sensitivity provided by this method will potentially allow high-precision robust measurements with cevns and particularly, will resolve the characteristic degeneracies appearing in new physics scenarios. | novel approach for the study of coherent elastic neutrino-nucleus scattering |
deuteron disintegration by charged-current neutrino (cc ν ) scattering offers the possibility to determine the energy of the incident neutrino by measuring in coincidence two of the three resulting particles: a charged lepton (usually a muon) and two protons, where we show that this channel can be isolated from all others—for instance, from those with a pion in the final state. we discuss the kinematics of the process for several detection scenarios, both in terms of kinematic variables that are natural from a theoretical point of view and others that are better matched to experimental situations. the deuteron structure is obtained from a relativistic model (involving an approximation to the bethe-salpeter equation) as an extension of a previous, well-tested model used in deuteron electrodisintegration. we provide inclusive and coincidence (semi-inclusive) cross sections for a variety of kinematic conditions, using the plane-wave impulse approximation, introducing final-state hadronic exchange terms (plane-wave born approximation) and final-state hadronic interactions (distorted-wave born approximation). | coincidence charged-current neutrino-induced deuteron disintegration |
to observe the neutrino-nucleus coherent scattering as well as for dark matter search, a detection system with ultra-low energy high purity germanium detector has been set up by the texono collaboration in kuo-sheng nuclear power plant. owing to the weak nature and small recoil energy of these rare events, understanding of background sources and their contribution to the energy spectrum are the key factors in this experiment. in this report, we will focus in detail on the different sources of backgrounds in the texono experiment and the techniques used to reject/minimize them. | background rejection of texono experiment to explore the sub-kev energy region with hpge detector |
it is planned to use linear alkylbenzene (lab) as the organic solvent for the jiangmen underground neutrino observatory (juno) liquid scintillator detectors, due to its ultra-transparency. however, the current rayleigh scattering length calculation for lab disagrees with the experimental measurement. this paper reports for the first time that the rayleigh scattering of lab is anisotropic, with a depolarization ratio of 0.31±0.01(stat.)±0.01(sys.). we use an indirect method for rayleigh scattering measurement with the einstein-smoluchowski-cabannes formula, and the rayleigh scattering length of lab is determined to be 28.2±1.0 m at 430 nm. | rayleigh scattering and depolarization ratio in linear alkylbenzene |
the large quantities of antineutrinos produced through the decay of fission fragments in nuclear reactors provide an opportunity to study the properties of these particles and investigate their use in reactor monitoring. the reactor antineutrino spectra are measured using specialized, large area detectors that detect antineutrinos through inverse beta decay, electron elastic scattering, or coherent elastic neutrino nucleus scattering; although, inverse beta decay is the only demonstrated method so far. reactor monitoring takes advantage of the differences in the antineutrino yield and spectra resulting from uranium and plutonium fission providing an opportunity to estimate the fissile material composition in the reactor. recent experiments reveal a deviation between the measured and calculated antineutrino flux and spectra indicating either the existence of yet undiscovered neutrino physics, uncertainties in the reactor source term calculation, incorrect nuclear data, or a combination of all three. to address the nuclear data that impact the antineutrino spectrum calculations and measurements, an international group of over 180 experts in antineutrino physics, reactor analysis, detector development, and nuclear data came together during the workshop on nuclear data for reactor antineutrino measurements (wondram) to discuss nuclear data needs and achieve concordance on a set of recommended priorities for nuclear data improvements. three topical sessions provided a forum to gain consensus amongst the participants on the most important data improvements to address two goals: 1) understand the reactor anomaly and 2) improve the ability to monitor reactors using antineutrinos. this report summarizes the outcomes of the workshop discussions and the recommendations for nuclear data efforts that reduce reactor antineutrino measurement uncertainties. | nuclear data to reduce uncertainties in reactor antineutrino measurements: summary report of the workshop on nuclear data for reactor antineutrino measurements (wondram) |
the coherent neutrino-nucleus interaction experiment (connie) uses fully depleted high-resistivity ccds (charge coupled devices) with the aim of detecting the coherent elastic scattering of reactor antineutrinos off silicon nuclei and probing physics beyond the standard model. the analysis of the 2016‖2018 data allowed us to set an upper limit at 95% confidence level on the coherent scattering rate, which was used to place stringent constraints on simplified extensions of the standard model with light scalar and vector mediators. in 2019, the experiment operated with an improved readout and a lower energy threshold of 50 ev. we present the performance of the connie experiment, new results of the analysis of 2019 data, and the recent update of the detector with skipper ccds. | low-energy reactor neutrino physics with the connie experiment |
i describe physics potential and experimental prospects for coherent elastic neutrino-nucleus scattering (cevns), a process which has not yet been observed. germanium- based detectors represent a promising technology for cevns experiments. i focus primarily on stopped-pion neutrino sources. | coherent elastic neutrino-nucleus scattering |
we present theoretical predictions in the framework of the anp model for single pion production (π+,π0) in νμ and ν¯μ scattering off mineral oil and plastic. our results for the integrated cross sections and flux-averaged differential distributions are compared to all available data of the miniboone and miner ν a experiments. while our predictions slightly undershoot the miniboone data, they reproduce the normalization of the miner ν a data for the kinetic energy distribution. for the dependence on the polar angle, we reproduce the shape of the arbitrarily normalized data. | comparison of the adler-nussinov-paschos model with the data for neutrino induced single pion production from the miniboone and miner ν a experiments |
we present a determination of the neutral current weak axial charge $g^z_a(0)=-0.654(3)_{\rm stat}(5)_{\rm sys}$ using the strange quark axial charge $g^s_a(0)$ calculated with lattice qcd. we then perform a phenomenological analysis, where we combine the strange quark electromagnetic form factor from lattice qcd with (anti)neutrino-nucleon scattering differential cross section from miniboone experiments in a momentum transfer region $0.24\lesssim q^2 \lesssim 0.71$ gev$^2$ to determine the neutral current weak axial form factor $g^z_a(q^2)$ in the range of $0\lesssim q^2\leq 1$ gev$^2$. this yields a phenomenological value of $g^z_a(0)=-0.687(89)_{\rm stat}(40)_{\rm sys}$. the value of $g^z_a(0)$ constrained by the lattice qcd calculation of $g^s_a(0)$, when compared to its phenomenological determination, provides a significant improvement in precision and accuracy and can be used to provide a constraint on the fit to $g^z_a(q^2)$ for $q^2>0$. this constrained fit leads to an unambiguous determination of (anti)neutrino-nucleon neutral current elastic scattering differential cross section near $q^2=0$ and can play an important role in numerically isolating nuclear effects in this region. we show a consistent description of $g^z_a(q^2)$ obtained from the (anti)neutrino-nucleon scattering cross section data requires a nonzero contribution of the strange quark electromagnetic form factor. we demonstrate the robustness of our analysis by providing a post-diction of the bnl e734 experimental data. | weak neutral current axial form factor using $(\\bar{\\nu})\\nu$-nucleon scattering and lattice qcd inputs |
charged-current neutrino-nucleus scattering is studied in the quasielastic region with various relativistic nuclear models that include the relativistic hartree, the nonlinear σ , the quark-meson coupling, and the chiral quark-meson coupling models. theoretical results at several kinematics are compared with experimental data measured from miniboone, t2k, microboone, and sciboone. while the theoretical double-differential cross sections in terms of the kinetic energy and polar angle of outgoing muon describe the t2k data well, the single-differential cross sections in terms of energy loss and the total cross sections of incident neutrino energy do not properly describe miniboone, microboone, and sciboone data. additionally, differences from the relativistic nuclear models are examined in detail by comparing with the experimental data. in particular, the miniboone data are not consistent with microboone and sciboone data, where the incident neutrino energies are below 1 gev. | quasielastic charged-current neutrino-nucleus scattering with relativistic nuclear models |
neutral current quasielastic (anti)neutrino scattering cross sections on a 12c target are analyzed using a realistic spectral function s (p ,e ) that gives a scaling function in accordance with the (e ,e') scattering data. the spectral function accounts for the nucleon-nucleon (nn) correlations by using natural orbitals from the jastrow correlation method and has a realistic energy dependence. the standard value of the axial mass ma=1.032 gev is used in all calculations. the effect of the final-state interaction on the spectral and scaling functions, as well as on the cross sections, is accounted for. a comparison of the calculations with the empirical data of the miniboone and bnl experiments is performed. our results are analyzed in comparison with those when nn correlations are not included and, also, with results from other theoretical approaches, such as the relativistic fermi gas, the relativistic mean field, and the relativistic green's function, as well as with the superscaling approach based on the analysis of quasielastic electron scattering. | neutral current quasielastic (anti)neutrino scattering beyond the fermi gas model at miniboone and bnl kinematics |
realistic nuclear structure calculations are presented for the event rates due to coherent elastic neutrino-nucleus scattering (ce ν ns ), assuming neutrinos from pion decay at rest, from nuclear reactors, and from earth's interior. we focus on the currently interesting germanium isotopes, 70,73,76ge, which constitute detector materials of the recently planned ce ν ns experiments. we study in addition the potential use of zn,7064 and 28si isotopes as promising ce ν ns detectors. from nuclear physics perspectives, recently, calculations have been carried out within the framework of the deformed shell model (dsm), based on realistic nuclear forces, and assessed on the reproducibility of spectroscopic nuclear properties. the high confidence level acquired by their agreement with experimental results and by their comparison with other mostly phenomenological calculations encouraged the use of dsm to extract predictions for the ce ν ns event rates of the above isotopes. our detailed estimation of the nuclear physics aspects of the recently observed neutral current coherent neutrino-nucleus scattering may shed light on unravelling the still remaining uncertainties for the ce ν ns process within and beyond the standard model. | coherent elastic neutrino-nucleus scattering (ce ν ns ) event rates for ge, zn, and si detector materials |
a core-collapse supernova (ccsn) provides a unique astrophysical site for studying neutrino-matter interactions. prior to the shock-breakout neutrino burst during the collapse of the iron core, a preshock νeburst arises from the electron capture of nuclei and it is sensitive to the low-energy coherent elastic neutrino-nucleus scattering (ceνns) which dominates the neutrino opacity. since the ceνns depends strongly on nonstandard neutrino interactions (nsis), which are completely beyond the standard model and yet to be determined, the detection of the preshock burst thus provides a clean way to extract the nsi information. within the spherically symmetric general-relativistic hydrodynamic simulation for the ccsn, we investigate the nsi effects on the preshock burst. we find that the nsi can maximally enhance the peak luminosity of the preshock burst almost by a factor of three, reaching a value comparable to that of the shock-breakout burst. future detection of the preshock burst will have critical implications on astrophysics, neutrino physics, and physics beyond the standard model. | supernova preshock neutronization burst as a probe of nonstandard neutrino interactions |
a description of the current state of the project for the study of coherent elastic neutrino-atom scattering using a tritium source and liquid helium detector is given. the project was proposed in our paper in 2019 and its main goal is to obtain a new record limit on the neutrino magnetic moment at a level below 10^{-12}\mu_b using a tritium antineutrino source with an intensity of 10 mci or even 40 mci. | a proposal for experiment with high-intensity tritium neutrino source in sarov: the search for coherent elastic neutrino-atom scattering and neutrino magnetic moment |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.