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background: a quantitative understanding of neutrino interactions with nuclei is needed for precision era neutrino long baseline experiments (minos, nova, dune) which all use nuclear targets. pion production is the dominant reaction channel at the energies of these experiments. purpose: investigate the influence of nuclear effects on neutrino-induced pion production cross sections and compare predictions for pion-production with available data. method: the giessen boltzmann-uehling-uhlenbeck (gibuu) model is used for the description of all incoherent channels in neutrino-nucleus reactions. results: differential cross sections for charged and neutral pion production for the miner ν a neutrino and antineutrino flux are calculated. an estimate for the coherent cross section is obtained from a comparison of data with theoretical results for incoherent cross sections. the invariant mass (w ) distribution of the δ resonances produced is analyzed. conclusions: final state interactions affect the pion kinetic energy spectra significantly. the data for charged pion production at miner ν a are compatible with the results of calculations using elementary data taken from an old argonne national laboratory experiment. remaining differences for charged pion production can be attributed to coherent production; the data for antineutrino induced neutral pion production, where no coherent contribution is present, are reproduced quite well. the analysis of w distributions shows that sharp cuts on experimentally reconstructed invariant masses lead to shape distortions of the true w distributions for nuclear targets. | pion production in high-energy neutrino reactions with nuclei |
we study the scattering of neutrinos on polarized and unpolarized free nucleons, and also the polarization of recoil particles in these scatters. in contrast to electromagnetic processes, the parity-violating weak interaction gives rise to large spin asymmetries at leading order. future polarization measurements could provide independent access to the proton axial structure and allow the first extraction of the pseudoscalar form factor from neutrino data without the conventional partially conserved axial current (pcac) ansatz and assumptions about the pion-pole dominance. the pseudoscalar form factor can be accessed with precise measurements with muon (anti)neutrinos of a few hundreds mev of energy or with tau (anti)neutrinos. the axial form factor can be extracted from scattering measurements using accelerator neutrinos of all energies. | axial and pseudoscalar form factors from charged current quasielastic neutrino-nucleon scattering |
in this work, we investigate the beyond standard model (bsm) impact of leptophilic u(1) models, namely u (1 )lμ-le , u (1 )le-lτ and u (1 )lμ-lτ on coherent elastic neutrino-nucleus scattering (ce ν ns ) and hence its effect on dark matter (dm) direct detection experiments. imposing the latest relevant experimental constraints on these models, we obtain o (50 %) enhancement for case of u (1 )lμ-lτ in a region mz'≈20 mev . subsequently, we observe that the enhancement seen in ce ν ns is roughly getting translated to enhancement by a factor of 2.7 (for germanium based detectors) and 1.8 (for xenon based detectors) in the neutrino scattering event rate which eventually enhances the neutrino floor by the same amount. this enhancement is more prominent in the region with dm masses less than 10 gev. the model parameter space that leads to this enhancement, can simultaneously explain both anomalous magnetic moment of muon ((g -2 )μ) and observed dm relic density, in a modified scenario. enhancement of neutrino floor requires increased number of dm-nucleon scattering events in the future dm direct detection experiments, to establish themselves to be dm signal events. in absence of any dm signal, those experiments can directly be used to measure the neutrino rate, quantifying the bsm effects. | neutrino floor in leptophilic u (1 ) models: modification in u (1 )lμ-lτ |
we have presented a review of the properties of neutrinos and their interactions with matter. the different (anti)neutrino processes like the quasielastic scattering, inelastic production of mesons and hyperons, and the deep inelastic scattering from the free nucleons are discussed and the results for the scattering cross sections are presented. the polarization observables for the leptons and hadrons produced in the final state, in the case of quasielastic scattering, are also studied. the importance of nuclear medium effects in the low, intermediate and high energy regions, in the above processes along with the processes of the coherent neutrino-nucleus scattering, coherent meson production, and trident production, have been highlighted. in some cases the results of the cross sections are also given and compared with the available experimental data as well as with the predictions in the different theoretical models. this study would be helpful in understanding the (anti)neutrino interaction cross section with matter in the few gev energy region relevant to the next generation experiments like dune, hyper-kamiokande, and other experiments with accelerator and atmospheric neutrinos. we have emphasized the need of better theoretical models for some of these processes for studying the nuclear medium effects in nuclei. | neutrinos and their interactions with matter |
we analyse the discrepancy between the neutron lifetimes measured in the bottle and beam experiments. following fornal and grinstein (phys. rev. lett. 120, 191801 (2018)) we propose an explanation of such a puzzle by the dark matter channels of the neutron decay. however, unlike fornal and grinstein in addition to the dark matter decay channel n -> \chi + e^- + e^+, where \chi is a dark matter dirac fermion and (e^-e^+) is an electron--positron pair, we assume the existence of the dark matter channel n -> chi + \nu_e + \bar{\nu}_e, where \nu_e \bar{\nu}_e is the electron neutrino-antineutrino pair. this allows to describe the discrepancy between the measurements of the neutron lifetime even in case of an unobservability of the dark matter decay channel n -> \chi + e^- + e^+, which may be below the reaction threshold. the existence of the coupling n -> \chi + e^- + e^+ can be observed experimentally by measuring electron-neutron scattering e^- + n -> \chi + e^- at very low electron energies, induced with the strength as of the decay n -> \chi + \nu_e + \bar{\nu}_e$. we propose a gauge invariant quantum field theory model with su_l(2)\times u_r(1) \times u_r'(1)\times u''_l(1) symmetry for the uv completion of the effective (n\chi \ell \bar{\ell}) interaction, where \ell(\bar{\ell}) is electron (positron) or neutrino(antineutrino). | neutron dark matter decays |
neutrino and dark matter experiments with large-volume (>~,2 1 ton) detectors can provide excellent sensitivity to signals induced by energetic light dark matter coming from the present universe. taking boosted dark matter as a concrete example of energetic light dark matter, we scrutinize two representative search channels, electron scattering and proton scattering including deep inelastic scattering processes, in the context of elastic and inelastic boosted dark matter, in a completely detector-independent manner. in this work, a dark gauge boson is adopted as the particle to mediate the interactions between the standard model particles and boosted dark matter. we find that the signal sensitivity of the two channels highly depends on the (mass-)parameter region to probe, so search strategies and channels should be designed sensibly especially at the earlier stage of experiments. in particular, the contribution from the boosted-dark-matter-initiated deep inelastic scattering can be subleading (important) compared to the quasi-elastic proton scattering, if the mass of the mediator is below (above) o (gev). we demonstrate how to practically perform searches and relevant analyses, employing example detectors such as darkside-20k, dune, hyper-kamiokande, and deepcore, with their respective detector specifications taken into consideration. for other potential detectors we provide a summary table, collecting relevant information, from which similar studies can be fulfilled readily. | optimizing energetic light dark matter searches in dark matter and neutrino experiments |
the possibility of measuring neutral-current coherent elastic neutrino-nucleus scattering (cenns) at the texono experiment has opened high expectations towards probing exotic neutrino properties. focusing on low threshold germanium-based targets with kg-scale mass, we find a remarkable efficiency not only for detecting cenns events due to the weak interaction, but also for probing novel electromagnetic neutrino interactions. specifically, we demonstrate that such experiments are complementary in performing precision standard model tests as well as in shedding light on sub-leading effects due to neutrino magnetic moment and neutrino charge radius. this work employs realistic nuclear structure calculations based on the quasi-particle random phase approximation (qrpa) and takes into consideration the crucial quenching effect corrections. such a treatment, in conjunction with a simple statistical analysis, shows that the attainable sensitivities are improved by one order of magnitude as compared to previous studies. | sensitivities to neutrino electromagnetic properties at the texono experiment |
rayleigh scattering poses an intrinsic limit for the transparency of organic liquid scintillators. this work focuses on the rayleigh scattering length of linear alkylbenzene (lab), which will be used as the solvent of the liquid scintillator in the central detector of the jiangmen underground neutrino observatory. we investigate the anisotropy of the rayleigh scattering in lab, showing that the resulting rayleigh scattering length will be significantly shorter than reported before. given the same overall light attenuation, this will result in a more efficient transmission of photons through the scintillator, increasing the amount of light collected by the photosensors and thereby the energy resolution of the detector. | rayleigh scattering of linear alkylbenzene in large liquid scintillator detectors |
the susperscaling model susav2, already available for charged-current neutrino-nucleus cross sections in the quasielastic region, is extended to the full inelastic regime. in the model the resonance production and deep inelastic reactions are described through the extension to the neutrino sector of the susav2 inelastic model developed for (e , e' ) reactions, which combines phenomenological structure functions with a nuclear scaling function. this work also compares two different descriptions of the δ resonance region, one based on a global scaling function for the full inelastic spectrum and the other on a semiphenomenological δ scaling function extracted from (e , e' ) data for this specific region and updated with respect to previous work. the results of the model are tested against (e , e' ) data on 12c, 16o, 40ca, and 40ar and applied to the study of the charged current inclusive neutrino cross-section on 12c and 40ar measured by the t2k, microboone, argoneut, and minerva experiments, thus covering several kinematical regions. | susav2 model for inelastic neutrino-nucleus scattering |
bullkid is an r&d project on a cryogenic particle detector to search for rare low-energy processes such as low-mass dark matter and neutrino coherent scattering off nuclei. the detector unit we are designing consists in an array of ~ 100 silicon absorbers sensed by phonon-mediated, microwave-multiplexed kinetic inductance detectors, with energy threshold below 100 ev and total target mass around 30 g. the single detector unit will be engineered to ensure a straightforward scalability to a future kg-scale experiment. | bullkid: bulky and low-threshold kinetic inductance detectors |
event detection rates for wimp-nucleus interactions are calculated for $^{71}$ga, $^{73}$ge, $^{75}$as and $^{127}$i (direct dark matter detectors). the nuclear structure form factors, that are rather independent of the underlying beyond the standard model particle physics scenario assumed, are evaluated within the context of the deformed nuclear shell model (dsm) based on hartree-fock nuclear states. along with the previously published dsm results for $^{73}$ge, the neutrino-floor due to coherent elastic neutrino-nucleus scattering (ce$\nu$ns), an important source of background to dark matter searches, is extensively calculated. the impact of new contributions to ce$\nu$ns due to neutrino magnetic moments and $z^\prime$ mediators at direct dark matter detection experiments is also examined and discussed. the results show that the neutrino-floor constitutes a crucial source of background events for multi-ton scale detectors with sub-kev capabilities. | novel neutrino-floor and dark matter searches with deformed shell model calculations |
with its enormous number of produced neutrinos the lhc is a prime facility to study the behavior of high-energy neutrinos. in this paper we propose a novel search strategy for identifying neutrino scattering via displaced appearing jets in the high granularity calorimeter of the cms endcap in the high luminosity run of the lhc. we demonstrate in a cut and count based analysis how the enormous hadronic background can be reduced while keeping most of the neutrino signal. this paper serves as a proof of principle study to illustrate the feasibility of the first direct observation of high-energy neutrinos coming from w decays. | potential of cms as a high-energy neutrino scattering experiment |
the present status of the field theoretical model studies of the deep inelastic scattering induced by (anti)neutrino on the nuclear targets in a wide range of bjorken variable x and four momentum transfer square q2 has been reviewed (haider et al. in phys rev c 84:054610, 2011, phys rev c 85:155201, 2012, nucl phys a 955:58, 2016; zaidi et al. in phys rev d 99:093011, 2019, phys rev d 101:033001, 2020; ansari et al. in phys rev d 102:113007, 2020). the effect of the nonperturbative corrections such as target mass corrections and dynamical higher twist effects, perturbative evolution of the parton densities, nuclear medium modifications in the nucleon structure functions, and nuclear isoscalarity corrections on the weak nuclear structure functions have been discussed. these structure functions have been used to obtain the differential scattering cross-sections. the various nuclear medium effects such as the fermi motion, binding energy, nucleon correlations, mesonic contributions, shadowing and antishadowing corrections relevant in the different regions of x and q2 have been discussed. the numerical results for the structure functions and the cross-sections are compared with some of the available experimental data including the recent results from minerva. the predictions are made in argon nuclear target which is planned to be used as a target material in dune at the fermilab. | deep inelastic (anti)neutrino-nucleus scattering |
a set of comparisons among neutrino interaction experiments (miniboone, minerva, t2k, and microboone) is presented. this gives a broad view of the field of neutrino-nucleus interactions. the emphasis is on charged current inclusive, quasielastic-like, and pion production experiments. measurements are compared in new ways. comparisons of recent data with available event generator codes are made more comprehensively than is regularly found in most previous publications. generator studies show sensitivities for experimental model dependence. effciencies calculated with different generators are presented in a novel way. a comparison of different forward folding techniques is also presented. | comparisons and challenges of modern neutrino-scattering experiments (tensions 2019 report) |
we introduce bullkid, an innovative phonon detector consisting of an array of dices acting as particle absorbers sensed by multiplexed kinetic inductance detectors (kids). the dices are carved in a thick crystalline wafer and form a monolithic structure. the carvings leave a thin common disk intact in the wafer, acting both as holder for the dices and as substrate for the kid lithography. the prototype presented consists of an array of 64 dices of 5.4x5.4x5 mm$^3$ carved in a 3" diameter, 5 mm thick silicon wafer, with a common disk 0.5 mm thick hosting a 60 nm patterned aluminum layer. the resulting array is highly segmented but avoids the use of dedicated holding structures for each unit. despite the fact that the uniformity of the kid electrical response across the array needs optimization, the operation of 8 units with similar features shows, on average, a baseline energy resolution of $26\pm7$ ev. this makes it a suitable detector for low-energy processes such as direct interactions of dark matter and coherent elastic neutrino-nucleus scattering. | bullkid: monolithic array of particle absorbers sensed by kinetic inductance detectors |
stopped muons, which are generic in pion-at-rest experiments, can shed light on heavy neutral leptons (hnls) in unexplored parameter spaces. if the hnl is lighter than the muon, the hnl can be produced from decays of muons and pions. the hnl will travel from the production location and decay into visible standard model (sm) modes, leaving signals inside downstream detectors. we find that in the case that the hnl dominantly mixes with muon neutrinos, the lsnd constraint on the mixing angle squared is stronger than all the previous constraints by more than an order of magnitude. in this study, we recast the lsnd measurement of the ν - e scattering. future experiments such as pip2-bd could further improve the sensitivity, provided they can distinguish the hnl events from backgrounds induced by the sm neutrinos. | heavy neutral leptons from stopped muons and pions |
the nucleus experiment aims to measure coherent elastic neutrino nucleus scattering of reactor anti-neutrinos using cryogenic calorimeters. operating at an overburden of 3 meters of water equivalent, muon-induced backgrounds are expected to be one of the dominant background contributions. besides a high efficiency to identify muon events passing the experimental setup, the nucleus muon veto has to fulfill tight spatial requirements to fit the constraints given by the experimental site and to minimize the induced detector dead-time. we developed highly efficient and compact muon veto modules based on plastic scintillators equipped with wavelength shifting fibers and silicon photo multipliers to collect and detect the scintillation light. in this paper, we present the full characterization of a prototype module with different light read-out configurations. we conclude that an efficient and compact muon veto system can be built for the nucleus experiment from a cube assembly of the developed modules. simulations show that an efficiency for muon identification of >99 % and an associated rate of 325 hz is achievable, matching the requirements of the nucleus experiment. | development of a compact muon veto for the nucleus experiment |
a search for new particles has been conducted using events with two high transverse momentum ( p t) τ leptons that decay hadronically, at least two high- p t jets, and missing transverse energy from the τ lepton decays. the analysis is performed using data from proton-proton collisions, collected by the cms experiment in 2015 at √{s}=13 tev, corresponding to an integrated luminosity of 2.1 fb-1. the results are interpreted in two physics models. the first model involves heavy right-handed neutrinos, nℓ ( ℓ = e , μ, τ), and right-handed charged bosons, wr, arising in a left-right symmetric extension of the standard model. masses of the wr boson below 2.35 (1.63) tev are excluded at 95% confidence level, assuming the n τmass is 0.8 (0.2) times the mass of the wr boson and that only the n τflavor contributes to the wr decay width. in the second model, pair production of third-generation scalar leptoquarks that decay into ττbb is considered. third-generation scalar leptoquarks with masses below 740 gev are excluded, assuming a 100% branching fraction for the leptoquark decay to a τ lepton and a bottom quark. this is the first search at hadron colliders for the third-generation majorana neutrino, as well as the first search for third-generation leptoquarks in the final state with a pair of hadronically decaying τ leptons and jets. [figure not available: see fulltext.] | search for heavy neutrinos or third-generation leptoquarks in final states with two hadronically decaying τ leptons and two jets in proton-proton collisions at √{s}=13 tev |
we present results for the quasielastic weak production of λ and σ hyperons induced by ν ¯ scattering off nuclei in the kinematical region of interest for accelerator neutrino experiments. we employ realistic hole spectral functions and we describe the propagation of the hyperons in the nuclear medium by means of a monte carlo cascade. the latter strongly modifies the kinematics and the relative production rates of the hyperons, leading to a nonvanishing σ+ cross section, to a sizable enhancement of the λ production and to a drastic reduction of the σ0 and σ- distributions. we also compute the quasielastic weak λc production cross section, paying special attention to estimate the uncertainties induced by the model dependence of the vacuum n →λc weak matrix element. in this regard, the recent besiii measurements of the branching ratios of λc→λ l+νl (l =e ,μ ) are used to benchmark the available theoretical predictions. | weak production of strange and charmed ground-state baryons in nuclei |
we consider the decoherence effects in the propagation of active neutrinos due to the nonforward neutrino scattering processes in a matter background composed of electrons and nucleons. we calculate the contribution to the imaginary part of the neutrino self-energy arising from such processes. since the initial neutrino state is depleted but does not actually disappear (the initial neutrino transitions into a neutrino of a different flavor but does not decay) those processes should be associated with decoherence effects that cannot be described in terms of the coherent evolution of the state vector. based on the formalism developed in our previous work for treating the nonforward scattering processes using the notion of the stochastic evolution of the state, we identify the jump operators, as used in the context of the master or lindblad equation, in terms of the results of the calculation of the nonforward neutrino scattering contribution to the imaginary part of the neutrino self-energy. as a guide to estimating the decoherence effects in situations of practical interest we give explicit formulas for the decoherence terms for different background conditions, and point out some of the salient features in particular the neutrino energy dependence. to establish contact with previous works in which the decoherence terms are treated as phenomenological parameters, we consider the solution to the evolution equation in the two-generation case. we give formulas that are useful for estimating the effects of the decoherence terms under various conditions and environments, including the typical conditions applicable to long baseline experiments, where matter effects are important. in those contexts the effects appear to be small, and indicative that if significant decoherence effects were to be found they would be due to nonstandard contributions to the decoherence terms. | neutrino decoherence in an electron and nucleon background |
we report on the design, production, and performance of compact 40-cm3 time projection chambers (tpcs) that detect fast neutrons by measuring the three-dimensional (3d) ionization distribution of nuclear recoils in 4he:co2 gas at atmospheric pressure. we use these detectors to characterize the fast-neutron flux inside the belle ii detector at the superkekb electron-positron collider in tsukuba, japan, where the primary design constraint is a small form factor. we find that the tpcs meet or exceed all design specifications, and are capable of measuring the 3d surface shape and charge density profile of ionization clouds from nuclear recoils and charged tracks in exquisite detail. scaled-up detectors based on the detection principle demonstrated here may be suitable for directional dark matter searches, measurements of coherent neutrino-nucleus scattering, and other experiments requiring precise detection of neutrons or nuclear recoils. | compact, directional neutron detectors capable of high-resolution nuclear recoil imaging |
pandax-ii has analyzed their complete data set of the electron recoil energy spectrum and has confirmed the xenon1t (1-7) kev excess, although the excess was also found compatible with the total background. treating the background as well known, in which case it provides a good fit to the observed spectrum, one can expect stronger constraints on any new physics model with this data. with this motivation, we derive constraints on the new general vector (v), axial-vector (a), scalar (s) and pseudoscalar (p) interactions if any of them contribute to the neutrino-electron elastic scattering. the derived constraints on the couplings at 90% c.l., respectively, are gv′ ≲ 32 ×10-7 for the mediator mass ≲ 10kev, ga′ ≲ 34 ×10-7 for mass ≲ 10kev, gs ≲ 49 ×10-7 for mass ≲ 20kev and gp ≲ 67 ×10-7 for mass ≲ 30kev. | constraints on general light mediators from pandax-ii electron recoil data |
recently, evidence for the observation of about 2 kev and below nuclear recoils from the coherent scattering of reactor anti-neutrinos off the germanium nuclei has been reported. we analyze the observed data to estimate the value of the weak mixing angle and constrain the neutrino millicharge, magnetic moment, charge radius and anapole moment contributing to the coherent scattering process. currently, there is no definite model available for the quenching factor at such low energies. to this end, we consider various models of the quenching factor and show how it affects the interpretation of the obtained results. we find that the bounds obtained are stronger in some cases while comparable or weaker in other cases which show a strong dependence on the choice and accuracy of a particular quenching factor model. the results are the first at such low-energy nuclear recoils. we present an exhaustive list of analytical functions for the different quenching factors corresponding to the existing models and to the data from various experiments. such functions will be useful for any new physics study using the nuclear recoils due to the reactor neutrinos. | $\\sin^2\\theta_w$ and neutrino electromagnetic interactions in ce$\\bar{\\nu}_e$ns with different quenching factors |
searches for new physics in the coherent elastic neutrino-nucleus scattering require a precise knowledge of the neutrino flux and energy spectrum. in this paper we investigate the feasibility and the performance of an experiment based on a ^{51}cr source, whose neutrino spectrum is known and whose activity can be heat-monitored at few permil level. with a 5 mci source placed at ∼ 25 cm from the detector, under an exposure of two ^{51}cr half-lives (55.4 days), we evaluate 3900 (900) counts on a 2000 cm^3 target of germanium (sapphire) featuring an energy threshold of 8 (20) ev. to further increase the exposure, multiple activations of the same source could be possible. | coherent elastic nuclear scattering of ^{51}cr neutrinos |
wimp-nucleon scattering is analyzed at order 1 / m in heavy wimp effective theory. the 1 / m power corrections, where m ≫mw is the wimp mass, distinguish between different underlying uv models with the same universal limit and their impact on direct detection rates can be enhanced relative to naive expectations due to generic amplitude-level cancellations at leading order. the necessary one- and two-loop matching calculations onto the low-energy effective theory for wimp interactions with standard model quarks and gluons are performed for the case of an electroweak su(2) triplet wimp, considering both the cases of elementary fermions and composite scalars. the low-velocity wimp-nucleon scattering cross section is evaluated and compared with current experimental limits and projected future sensitivities. our results provide the most robust prediction for electroweak triplet majorana fermion dark matter direct detection rates; for this case, a cancellation between two sources of power corrections yields a small total 1 / m correction, and a total cross section close to the universal limit for m ≳ few × 100gev. for the su(2) composite scalar, the 1 / m corrections introduce dependence on underlying strong dynamics. using a leading chiral logarithm evaluation, the total 1 / m correction has a larger magnitude and uncertainty than in the fermionic case, with a sign that further suppresses the total cross section. these examples provide definite targets for future direct detection experiments and motivate large scale detectors capable of probing to the neutrino floor in the tev mass regime. | power corrections to the universal heavy wimp-nucleon cross section |
spin-physics projects at j-parc are explained by including future possibilities. j-parc is the most-intense hadron-beam facility in the high-energy region above multi-gev, and spin physics will be investigated by using secondary beams of kaons, pions, neutrinos, muons, and antiproton as well as the primary-beam proton. in particle physics, spin topics are on muon g - 2, muon and neutron electric dipole moments, and time-reversal violation experiment in a kaon decay. here, we focus more on hadron-spin physics as for future projects. for example, generalized parton distributions (gpds) could be investigated by using pion and proton beams, whereas they are studied by the virtual compton scattering at lepton facilities. the gpds are key quantities for determining the three-dimensional picture of hadrons and for finding the origin of the nucleon spin including partonic orbital-angular-momentum contributions. in addition, polarized parton distributions and various hadron spin topics should be possible by using the high-momentum beamline. the strangeness contribution to the nucleon spin could be also investigated in principle with the neutrino beam with a near detector facility. | spin physics at j-parc |
coherent elastic neutrino-nucleus scattering (cevns) is the dominant neutrino scattering channel for neutrinos of energy $e_\nu < 100$ mev. we report a limit for this process using data collected in an engineering run of the 29 kg cenns-10 liquid argon detector located 27.5 m from the oak ridge national laboratory spallation neutron source (sns) hg target with $4.2\times 10^{22}$ protons on target. the dataset yielded $< 7.4$ observed cevns events implying a cross section for the process, averaged over the sns pion decay-at-rest flux, of $<3.4 \times 10^{-39}$ cm$^{2}$, a limit within twice the standard model prediction. this is the first limit on cevns from an argon nucleus and confirms the earlier csi non-standard neutrino interaction constraints from the collaboration. this run demonstrated the feasibility of the ongoing experimental effort to detect cevns with liquid argon. | first constraint on coherent elastic neutrino-nucleus scattering in argon |
dual-phase xenon detectors are widely used in dark matter direct detection experiments, and have demonstrated the highest sensitivities to a variety of dark matter interactions. however, a key component of the dual-phase detector technology—the efficiency of charge extraction from liquid xenon into gas—has not been well characterized. in this paper, we report a new measurement of the electron extraction efficiency (eee) in a small xenon detector using two monoenergetic decay features of ar 37 . by achieving stable operation at very high voltages, we measured the eee values at the highest extraction electric field strength reported to date. for the first time, an apparent saturation of the eee is observed over a large range of electric field; between 7.5 and 10.4 kv /cm extraction field in the liquid xenon the eee stays stable at the level of 1% (kv /cm )-1 . in the context of electron transport models developed for xenon, we discuss how the observed saturation may help calibrate this relative eee measurement to the absolute eee values. in addition, we present the implications of this result not only to current and future xenon-based dark matter searches, but also to xenon-based searches for coherent elastic neutrino-nucleus scatters. | electron extraction efficiency study for dual-phase xenon dark matter experiments |
we present a set of new generalized kinematic imbalance variables that can be measured in neutrino scattering. these variables extend previous measurements of kinematic imbalance on the transverse plane, and are more sensitive to modeling of nuclear effects. we demonstrate the enhanced power of these variables using simulation, and then use the microboone detector to measure them for the first time. we report flux-integrated single- and double-differential measurements of charged-current muon neutrino scattering on argon using a topolgy with one muon and one proton in the final state as a function of these novel kinematic imbalance variables. these measurements allow us to demonstrate that the treatment of charged current quasielastic interactions in genie version 2 is inadequate to describe data. further, they reveal tensions with more modern generator predictions particularly in regions of phase space where final state interactions are important. | measurement of nuclear effects in neutrino-argon interactions using generalized kinematic imbalance variables with the microboone detector |
stopped-pion experiments that measure coherent elastic neutrino-nucleus scattering (ce$\nu$ns) are sensitive to sterile neutrinos via disappearance. using timing and energy spectra to perform flavor decomposition, we show that the delayed electron neutrino component provides an independent test of short-baseline anomalies that hint at $\sim$ ev-mass sterile neutrinos. dedicated experiments will be sensitive to nearly the entire sterile neutrino parameter space consistent with short-baseline data. | short baseline neutrino anomalies at stopped pion experiments |
coherent elastic neutrino-nucleus scattering (ce νns) offers valuable sensitivity to physics beyond the standard model. the ricochet experiment will use cryogenic solid-state detectors to perform a precision measurement of the ce νns spectrum induced by the high neutrino flux from the institut laue-langevin nuclear reactor. the experiment will employ an array of detectors, each with a mass of ∼30 g and a targeted energy threshold of 50 ev. nine of these detectors (the "q-array") will be based on a novel transition-edge sensor (tes) readout style, in which the tes devices are thermally coupled to the absorber using a gold wire bond. we present initial characterization of a q-array-style detector using a 1 gram silicon absorber, obtaining a baseline root-mean-square resolution of less than 40 ev. | results from a prototype tes detector for the ricochet experiment |
we propose a method to identify jets consisting of all the visible remnants of a boosted top quark decaying semileptonically with an electron in the final state. an overlap of electron shower with the b quark initiated shower, and the large nontrivial energy-momentum carried by the invisible neutrino in the top quark decay are the two obstacles to achieving this aim. our method uses the distribution of energy in different parts of the detector to identify a jet containing an energetic electron, involves use of substructure of the jet to determine the momentum associated with the electron and then completes the identification of top jet with the construction of new variables which would reflect the top quark decay kinematics. the last part involves an ansatz of the existence of a massless, invisible four-momentum roughly collimated with the electron, whose four- momentum when combined with that of the the electron and the full jet, reconstructs to the w boson and the top quark respectively. we demonstrate the efficacy of this proposal using simulated data and show that our method not only reduces the backgrounds from light flavor jets, b jets from qcd, and hadronic top jets, it can also tell apart jets rich in electrons but not due to top quark decays. | jets with electrons from boosted top quarks |
we discuss unpolarized neutrino- and anti-neutrino-nucleon deep inelastic scattering using a chiral doublet of baryonic sources with explicit symmetry breaking, in a slice of ads5 with both a hard and soft wall. we explicitly derive the direct and transition form factors for the vector and axial-vector currents for the holographic dual of a proton and neutron. we use them to derive the s -channel structure functions for neutrino and antineutrino scattering on a proton and neutron in bulk. the t -channel contributions stemming from the pomeron and reggeon exchanges are also evaluated explicitly. the pertinent even and odd structure functions in the limit of large and small parton momentum fraction x are given. the results allow for the extraction of the nonperturbative parton distribution functions carried by the sea and valence quarks both at large-x and small-x regimes. our holographic parton distribution function (pdf) sets compare well with the les houches accord pdf (lhapdf) and the coordinated theoretical-experiment project on qcd (cteq) pdf sets in the large-x and small-x regimes in the intermediate range of q2<10 gev2 . | neutrino-nucleon dis from holographic qcd: pdfs of sea and valence quarks, form factors, and structure functions of the proton |
the paper presents a theoretical approach to the description of the relativistic scattering of a massive (neutral) lepton on a nucleus, in which the latter retains its integrity. the measurable cross section of this process includes the elastic (or coherent) contribution, when the nucleus remains in its original quantum state and the inelastic (incoherent) contribution, when the nucleus goes into another (excited) quantum state. transition from the elastic scattering regime to the inelastic scattering regime is regulated automatically by the dependence of the nucleon-nucleus form factors on the momentum transferred to the nucleus. at small momentum transfers elastic scattering dominates. as the transferred momentum increases, the contribution of the inelastic scattering increases, and the latter becomes dominant at sufficiently large transferred momenta. the interaction of a pointlike lepton with structureless nucleons of the target nucleus is parameterized with four effective coupling constants, reflecting the (axial)vector nature of the weak interaction. the scattering of massive (anti)neutrinos interacting with nucleons through the $v \mp a$ currents of the standard model is considered in detail. because of the nonzero masses, an additional channel arises for elastic and inelastic scattering of these (anti)neutrinos on nuclei due to the possibility of changing the helicity of these (anti)neutrinos. for example, despite the smallness of the masses at (kinetic) energies of (anti)neutrinos much lower than the neutrino masses (for example, relic ones), the cross section of their interaction with the nucleus turns out to be many times enhanced, at least due to the "nucleus coherence effect". the expressions obtained for the cross sections are applicable to any precision data analysis involving neutrinos and antineutrinos, especially when non-zero neutrino masses can be taken into account. these expressions can also be used in the analysis of experiments on direct detection of (neutral) massive weakly interacting relativistic dark matter particles since, unlike the generally accepted case, they simultaneously take into account both elastic and inelastic interactions of the particles. the presence of an "inelastic signal" with its characteristic signature may be the only registrable evidence of interaction of the dark matter particle with the nucleus. | on massive neutral lepton scattering on nucleus |
low-energy compton scattering is an important background for sub-gev dark matter direct-detection and other experiments. current compton scattering calculations typically rely on assumptions that are not valid in the low-energy region of interest, beneath ~ 50 ev. here we relate the low-energy compton scattering differential cross section to the dielectric response of the material. our new approach can be used for a wide range of materials and includes all-electron, band structure, and collective effects, which can be particularly relevant at low energies. we demonstrate the strength of our approach in several solid-state systems, in particular si, ge, gaas, and sic, which are relevant for current and proposed experiments searching for dark matter, neutrinos, and millicharged particles. | low-energy compton scattering in materials |
a search is performed for a heavy particle decaying into different-flavour, dilepton final states, using 139 fb−1 of proton-proton collision data at √{s } = 13 tev collected in 2015-2018 by the atlas detector at the large hadron collider. final states with electrons, muons and hadronically decaying tau leptons are considered (eμ, eτ or μτ). no significant excess over the standard model predictions is observed. upper limits on the production cross-section are set as a function of the mass of a z' boson, a supersymmetric τ-sneutrino, and a quantum black-hole. the observed 95% cl lower mass limits obtained on a typical benchmark model z' boson are 5.0 tev (eμ), 4.0 tev (eτ), and 3.9 tev (μτ), respectively. | search for lepton-flavour violation in high-mass dilepton final states using 139 fb−1 of pp collisions at √{s } = 13 tev with the atlas detector |
the paper presents a world-leading scintillation light yield among inorganic crystals measured from a 0.5 kg pure-csi detector operated at 77 kelvin. scintillation photons were detected by two 2-inch hamamatsu sipm arrays equipped with cryogenic front end electronics. benefiting the light yield enhancement of pure-csi at low temperatures and the high photon detection efficiency of sipm, a light yield of 52.1 photoelectrons per kev energy deposit was obtained for x-rays and {\gamma}-rays with energies from 5.9 kev to 60 kev. instrumental and physical effects in the light yield measurement is carefully analyzed. this is the first stable cryogenic operation of kg-scale pure-csi crystal readout by sipm arrays at liquid nitrogen temperatures for several days. the world-leading light yield opens a door for the usage of pure-csi crystal in several fields, particularly in detecting the coherent elastic neutrino-nucleus scattering of reactor neutrinos. potentials of using pure-csi crystals in neutrino physics are discussed in the paper. | reactor neutrino physics potentials of cryogenic pure-csi crystal |
we have studied the differential cross section as well as the longitudinal and perpendicular components of polarization of the final hyperon (λ ,σ ) produced in the antineutrino induced quasielastic charged current reactions on nucleon and nuclear targets. the nucleon-hyperon transition form factors are determined from the experimental data on quasielastic (δ s =0 ) charged current (anti)neutrino-nucleon scattering and the semileptonic decay of neutron and hyperons assuming g-invariance, t-invariance, and su(3) symmetry. the vector transition form factors are obtained in terms of nucleon electromagnetic form factors for which various parametrizations available in the literature have been used. a dipole parametrization for the axial vector form factor and the pseudoscalar transition form factor derived in terms of the axial vector form factor assuming pcac and gt relation extended to the strangeness sector has been used in numerical evaluations. the flux averaged cross section and polarization observables corresponding to the cern gargamelle experiment have been calculated for quasielastic hyperon production and found to be in reasonable agreement with the experimental observations. the numerical results for the flux averaged differential cross section d/σ d q2 and longitudinal (perpendicular) polarization pl(q2)(pp(q2)) relevant for the antineutrino fluxes of miner ν a , microboone, and t2k experiments have been presented. this will be useful in interpreting future experimental results on production cross sections and polarization observables from the experiments on the quasielastic production of hyperons induced by antineutrinos and exploring the possibility of determining the axial vector and pseudoscalar form factors in the strangeness sector. | quasielastic production of polarized hyperons in antineutrino-nucleon reactions |
silicon photomultiplier (sipm) is a sensor that can detect low-light signals lower than the single-photon level. in order to study the properties of neutrinos at a low detection threshold and low radioactivity experimental background, a low-temperature csi neutrino coherent scattering detector is designed to be read by the sipm sensor. less thermal noise of sipm and more light yield of csi crystals can be obtained at the working temperature of liquid nitrogen. the breakdown voltage (vbd) and dark count rate (dcr) of sipm at liquid nitrogen temperature are two key parameters for coherent scattering detection. in this paper, a low-temperature test is conducted on the mass-produced on semiconductor j-series sipm. we design a cryogenic system for cooling sipm at liquid nitrogen temperature and the changes of operating voltage and dark noise from room to liquid nitrogen temperature are measured in detail. the results show that sipm works at the liquid nitrogen temperature, and the dark count rate drops by six orders of magnitude from room temperature (120 khz/mm2) to liquid nitrogen temperature (0.1 hz/mm2). | characterization of a mass-produced sipm at liquid nitrogen temperature for csi neutrino coherent detectors |
the impact of measurements of heavy-flavour production in deep inelastic ep scattering and in pp collisions on parton distribution functions is studied in a qcd analysis at next-to-leading order. recent combined results of inclusive and heavy-flavour produc- tion cross sections in deep inelastic scattering at hera are investigated together with heavy-flavour production measurements at the lhc. differential cross sections of charm- and beauty-hadron production measured by the lhcb collaboration at the centre-of-mass energies of 5, 7 and 13 tev as well as the recent measurements of the alice experiment at the centre-of-mass energies of 5 and 7 tev are explored. these data impose additional constraints on the gluon and the sea-quark distributions at low partonic fractions x of the proton momentum, down to x ≈ 10-6. the impact of the resulting parton distribution function in the predictions for the prompt atmospheric-neutrino fluxes is studied. | improved constraints on parton distributions using lhcb, alice and hera heavy-flavour measurements and implications for the predictions for prompt atmospheric-neutrino fluxes |
in this study, we apply lhc data to constrain the extension of the standard model by an anomaly-free u(1) lμ -lτ gauge group; this model contains a new gauge boson (z‧) and a scalar dark matter particle (ϕdm). we recast a large number of lhc analyses of multi-lepton final states by the atlas and cms collaborations. we find that for 10gev <mz‧ < 60 gev the strongest constraint comes from a dedicated z‧ search in the 4μ final state by the cms collaboration; for larger z‧ masses, searches for final states with three leptons plus missing et are more sensitive. searches for final states with two leptons and missing et, which are sensitive to z‧ decays into dark matter particles, can only probe regions of parameter space that are excluded by searches in the 3 and 4 lepton channels. the combination of lhc data excludes values of z‧ mass and coupling constant that can explain the deficit in gμ - 2 for 4gev ≤mz‧ ≤ 500 gev. however, for much of this range the lhc bound is weaker than the bound that can be derived from searches for "trident" events in neutrino-nucleus scattering. | constraints on u(1) lμ -lτ from lhc data |
we study the effects on the spectrum and distribution of high-energy neutrinos due to scattering with dark matter both outside and within our galaxy, focusing on the neutrinos observed by the icecube experiment with energies up to several pev. if these neutrinos originate from extra-galactic astrophysical sources, then scattering in transit with dark matter particles will delay their arrival to earth. this results in a cut-off in their spectrum at an energy set by the scattering cross section, allowing us to place an upper limit on cross sections $\sigma$ which increase with energy e at the level of $\sigma$ < 10^{-17} x (m / gev) x (e / pev)^2 cm^2, for dark matter particles of mass m. once these neutrinos enter our galaxy, the large dark matter densities result in further scattering, especially towards the galactic centre. intriguingly, we find that for $\sigma$ ~ 10^{-22} x (m / gev) x (e / pev)^2 cm^2, the distribution of the neutrinos on the sky has a small cluster of events towards the centre of the galaxy, potentially explaining the ~2 sigma excess seen by icecube in this region without needing a galactic source. | spectral and spatial distortions of pev neutrinos from scattering with dark matter |
the nucleus experiment aims at measuring the coherent elastic scattering of nuclear reactor antineutrinos off nuclei using cryogenic calorimeters. operating at an overburden of 3 m.w.e., muon-induced backgrounds are expected to be dominant. it is therefore essential to develop an efficient muon veto, with a detection efficiency of more than 99 %. this will be realized in nucleus through a compact cube assembly of plastic scintillator panels. in order to prevent a large unshielded area where the cryostat intersects the shielding arrangement without unnecessarily increasing the induced detector dead time, a novel concept has been investigated, featuring a plastic scintillator-based active muon veto operating inside the nucleus cryostat at sub-kelvin temperatures. the verification of the key physical aspects of this cryogenic muon veto detector led to the first reported measurements of organic plastic scintillators at sub-kelvin temperatures. the functionality of the principal scintillation process of organic plastic scintillators at these temperatures has been confirmed. on the basis of these findings, a disk-shape plastic scintillator equipped with wavelength shifting fibers and a silicon photomultiplier to guide and detect the scintillation light has been developed. the nucleus cryogenic muon veto will be the first of its kind to be operated at sub-kelvin temperatures. | development of an organic plastic scintillator-based muon veto operating at sub-kelvin temperatures for the nucleus experiment |
the nuclear medium effects in the nuclear structure functions and differential cross sections in the deep inelastic scattering (dis) of charged lepton and neutrino from nuclear targets are studied in the region of large x including x ≥1 . the nuclear medium effects due to the fermi motion and the binding energy of nucleons and the nucleon correlations are included using nucleon spectral function calculated in a microscopic field theoretical model. the numerical results for the nuclear structure functions and the cross sections are obtained using the nucleon structure function evaluated at the next-to-next-to-leading order (nnlo) with the martin-motylinski-harland lang-thorne (mmht) parametrization of the nucleonic parton distribution functions (pdfs) and are compared with the available experimental data on electron scattering from the jefferson lab (jlab) and slac nuclear physics facility (npas). in the case of neutrino scattering the results are relevant for understanding the dis contributions to the recent inclusive cross sections measured by the main injector neutrino experiment to study v-a interactions (minerva) as well as theoretical predictions are made for deep underground neutrino experiment (dune). the importance of isoscalarity corrections in heavier nuclear targets as well as the effect of the kinematic cut on the cm energy w in defining the dis region have also been discussed. | nuclear medium effects in lepton-nucleus dis in the region of x ≳1 |
we investigate the effects of the transitional magnetic dipole moment of the active-to-heavy-neutrino associated with a new neutral gauge boson $z'$ on neutrino-nucleon scattering at the forward search experiment-$\nu$ (faser$\nu$). we consider the neutral-current neutrino-nucleon scattering ($\nu a\rightarrow n a$) as the production mechanism of the heavy neutrino $n$ at faser$\nu$ and estimate the sensitivity reach on the magnetic moment coupling $\mu_{\nu_\alpha}$ for a range of heavy neutrino mass ($1\,{\rm gev} < m_{n} < 70 {\rm gev}$). in this study, we consider three benchmark models, in which the heavy neutrino is coupled to $l_e$, $l_\mu$ or $l_\tau$ doublet, respectively. | constraining the active-to-heavy-neutrino transitional magnetic moments associated with the $z'$ interactions at faser$\\nu$ |
we discuss the nuclear interactions of neutrinos versus those of antineutrinos, a relevant comparison for cp violation experiments in the neutrino sector. we consider the miniboone quasielastic-like double-differential neutrino and antineutrino cross sections that are dependent on the energy profiles of the neutrino fluxes and hence specific to the miniboone setup. we combine them introducing their sum (ν +ν ¯) and their difference (ν -ν ¯) . we show that the last combination gives general information on the multinucleon content of the axial-vector interference term. our theoretical model reproduces well the two cross-section combinations, confirming the need for a sizable multinucleon component. | neutrino versus antineutrino cross sections and cp violation |
neutrino-nucleus quasielastic scattering is studied in the plane-wave impulse approximation for three nuclear models: the relativistic fermi gas (rfg), the independent-particle shell model (ipsm), and the natural orbitals (no) model with lorentzian dependence of the excitation energy. a complete study of the kinematics of the semi-inclusive process and the associated cross sections are presented and discussed for 40ar and 12c. inclusive cross sections are also obtained by integrating the semi-inclusive expressions over the outgoing hadron. results are consistent with previous studies restricted to the inclusive channel. in particular, a comparison with the analytical results for the rfg model is performed. explicit expressions for the hadronic tensor and the 10 semi-inclusive nuclear responses are given. theoretical predictions are compared with semi-inclusive experimental data from t2k experiment. | semi-inclusive charged-current neutrino-nucleus cross sections in the relativistic plane-wave impulse approximation |
we propose a fully nonperturbative method to compute inelastic lepton-nucleon (ℓn ) scattering cross sections using lattice quantum chromodynamics (qcd). the method is applicable even at low energies, such as the energy region relevant for the recent and future neutrino-nucleon scattering experiments, for which perturbative analysis is invalidated. the basic building block is the forward compton-scattering amplitude, or the hadronic tensor, computed on a euclidean lattice. a total cross section is constructed from the hadronic tensor by multiplying a phase space factor and integrating over the energy and momentum of final hadronic states. the energy integral that induces a sum over all possible final states is performed implicitly by promoting the phase space factor to an operator written in terms of the transfer matrix on the lattice. the formalism is imported from that of the inclusive semileptonic b meson decay [p. gambino and s. hashimoto, phys. rev. lett. 125, 032001 (2020), 10.1103/physrevlett.125.032001] and generalized to compute the ℓn scattering cross sections and their moments, as well as the virtual correction to the nuclear β decay. | towards fully nonperturbative computations of inelastic ℓn scattering cross sections from lattice qcd |
the first observation of coherent elastic neutrino-nucleus scattering (ce νns), reported by the coherent collaboration in 2017, paved the way for a new generation of experiments using reactor ν¯e and aiming at precisely measuring this process. in this context, the basket (bolometers at sub-kev energy thresholds) r&d project investigates the use of cryogenic detectors for a reactor ce νns experiment. this article reports on the first test of a mo-doped lithium tungstate scintillating bolometer (⊘18 × 7 mm, 8 g), performed in an aboveground laboratory at csnsm, orsay (france). the detector bolometric performance (energy and time response, particle identification capabilities) and radiopurity have been studied and confirm the promising potential of lithium tungstate-based bolometric detectors for the measurement of ce νns at reactors. | first test of a li2wo4(mo) bolometric detector for the measurement of coherent neutrino-nucleus scattering |
event spectra of neutrino - 16o charged-current reactions at super-kamiokande are evaluated for a future supernova neutrino burst. since these channels are expected to be useful for diagnosing a neutrino spectrum with high average energy, the evaluations are performed not only for an ordinary supernova neutrino model but also for a model of neutrino emission from a black-hole-forming collapse. using shell model results, whose excitation energies are consistent with the experimental data, the cross sections of the 16o(νe,e-)x and 16o(ν-e,e+)x reactions for each nuclear state with a different excitation energy are employed in this study. it is found that, owing to the components of the reaction with higher excitation energy, the event spectrum becomes 4-7mev softer than in the case without considering the excitation energies. in addition, a simplified approach to evaluating the event spectra is proposed for convenience, and its validity is examined. | charged-current scattering off the 16o nucleus as a detection channel for supernova neutrinos |
neutrino-nucleus and antineutrino-nucleus interactions, when the nucleus conserves its integrity, are discussed with coherent (elastic) and incoherent (inelastic) scattering regimes taken into account. in the first regime the nucleus remains in the same quantum state after the scattering and the cross-section depends on the quadratic number of nucleons. in the second regime the nucleus changes its quantum state and the cross-section has an essentially linear dependence on the number of nucleons. the coherent and incoherent cross-sections are driven by a nuclear nucleon form-factor squared term and a term, respectively. one has a smooth transition between the regimes of coherent and incoherent (anti)neutrino-nucleus scattering. due to the neutral current nature these elastic and inelastic processes are indistinguishable if the nucleus recoil energy is only observed. one way to separate the coherent signal from the incoherent one is to register quanta from deexcitation of the nucleus excited during the incoherent scattering. another way is to use a very low-energy threshold detector and collect data at very low recoil energies, where the incoherent scattering is vanishingly small. in particular, for and neutrino energies of 30-50 mev the incoherent cross-section is about 15-20% of the coherent one. therefore, the coherent experiment (with ) has measured the coherent elastic neutrino nucleus scattering (cens) with the inelastic admixture at a level of 15-20%, if the excitation quantum escapes its detection. | on coherent neutrino and antineutrino scattering off nuclei |
pion production on nuclei constitutes a significant part of the total cross section in experiments involving few-gev neutrinos. combined analyses of data on deuterium and heavier nuclei points to tensions between the bubble-chamber data and the data of the miner ν a experiment, which are often ascribed to unspecified nuclear effects. in experimental analysis use is made of approximate treatments of nuclear dynamics, usually in a fermi gas approach with classical treatments of the reaction mechanism, and fits are often performed by simply rescaling cross sections. to understand the origin of these tensions, check the validity of approximations, and to further advance the description of neutrino pion production on nuclei, a microscopic quantum mechanical framework is needed to compute nuclear matrix elements. we use the local approximation to the relativistic distorted wave impulse approximation to calculate the nuclear matrix elements. we include the distortion of wave functions of the final-state nucleon in a real energy-dependent potential. we compare results with and without distortion. to perform this comparison under conditions relevant to neutrino experiments, we compute cross sections for the miner ν a and t2k charged-pion production datasets. the inclusion of nucleon distortion leads to a reduction of the cross section up to 10%, but to no significant change in shape of the flux-averaged cross sections. results with and without distortion compare favorably to experimental data, with the exception of the low-q2 miner ν a π+ data. we point out that hydrogen target data from bebc is also overpredicted at low q2, and the data-model discrepancy is similar in shape and magnitude as what is found in comparison to miner ν a data. including nucleon distortion alone cannot explain the overprediction of low-q2 cross sections measured by miner ν a . the similar overprediction of bebc data on hydrogen means that it is impossible to ascribe this discrepancy solely to a nuclear effect. axial form factors might not be constrained in a satisfactory way by the argonne and brookhaven national laboratories (anl/bnl) data alone. axial couplings and their q2 dependence should ideally be derived from more precise data on hydrogen and deuterium. nuclear matrix elements should be tested with e.g., electron scattering data for which nucleon level physics is better constrained. | assessing the theory-data tension in neutrino-induced charged pion production: the effect of final-state nucleon distortion |
measurements of the total and differential fiducial cross sections for the z boson decaying into two neutrinos are presented at the lhc in proton-proton collisions at a center-of-mass energy of 13 tev. the data were collected by the cms detector in 2016 and correspond to an integrated luminosity of 35.9 fb−1. in these measurements, events are selected containing an imbalance in transverse momentum and one or more energetic jets. the fiducial differential cross section is measured as a function of the z boson transverse momentum. the results are combined with a previous measurement of charged-lepton decays of the z boson. the measured total fiducial cross section for events with z boson transverse momentum greater than 200 gev is 3000−170+180 fb. | measurement of the z boson differential production cross section using its invisible decay mode (z →ν ν ¯) in proton-proton collisions at √{s } = 13 tev |
the ricochet reactor neutrino observatory is planned to be installed at the laue langevin institute starting mid-2022. its scientific goal is to perform a low-energy and high precision measurement of the coherent elastic neutrino-nucleus scattering spectrum in order to explore exotic physics scenarios. ricochet will host two cryogenic detector arrays: the cryocube (ge target) and the q-array (zn target), operated at 10 mk. the 1 kg ge cryocube will consist of 27 ge crystals instrumented with ntd-ge thermal sensors and charge collection electrodes for a simultaneous heat and ionization readout to reject the electromagnetic backgrounds (gamma, beta, x-rays). we present the status of its front-end electronics. the first stage of amplification is made of high electron mobility transistors developed by cnrs/c2n laboratory, optimized to achieve ultra-low noise performance at 1 k with a dissipation as low as 15 μ w per channel. our noise model predicts that 10 ev heat and 20 evee rms baseline resolutions are feasible with a high dynamic range for the deposited energy (up to 10 mev) thanks to loop amplification schemes. such resolutions are mandatory to have a high discrimination power between nuclear and electron recoils at the lowest energies. | hemt-based 1 k front-end electronics for the heat and ionization ge cryocube of the future ricochet ceν ns experiment |
the charged-current quasi-elastic scattering of muon neutrinos on a carbon target is analyzed using the relativistic distorted-wave impulse approximation (rdwia), taking into account the contribution of the two-particle and two-hole meson exchange current (mec) to the weak response functions. a fit the rdwia +mec model to the miniboone neutrino data is performed, and the best-fit value of nucleon axial mass ma≈1.20 gev is obtained. we also extract the values of the axial form factor fa(q2) as a function of the squared momentum transfer q2 from the measured d σ /d q2 cross section. the flux-integrated charged-current quasi-elastic-like differential cross sections for neutrino scattering at energies of the nova experiment are estimated within the rdwia +mec approach. | testing of quasi-elastic neutrino charged-current and two-body meson exchange current models with the miniboone neutrino data and analysis of these processes at energies available at the nova experiment |
the current status of the red-100 experiment is described. the detector is being prepared for the experiment on the first observation of a coherent elastic neutrino-nucleus scattering at the kalinin nuclear power plant (russia). the estimation of the signal event rate for this process has been done by monte carlo with the use of the full detector geometry and the modern data on the ionisation yield for nuclear recoils in the liquid xenon. the simulation has shown very promising significant increase of it, by at least a factor of 2, in compare with our previous estimations. | status of the red-100 experiment |
the coherent collaboration is deploying a suite of low-energy detectors in a low-background corridor of the ornl spallation neutron source (sns) to measure coherent elastic neutrino-nucleus scattering (cevns) on an array of nuclear targets employing different detector technologies. a measurement of cevns on different nuclei will test the n2-dependence of the cevns cross section and further the physics reach of the coherent effort. the first step of this program has been realized recently with the observation of cevns in a 14.6 kg csi detector. operation and deployment of ge and nai detectors are also underway. a 22 kg, single-phase, liquid argon detector (cenns-10) started data-taking in dec. 2016 and will provide results on cevns from a lighter nucleus. initial results indicate that light output, pulse-shape discrimination, and background suppression are sufficient for a measurement of cevns on argon. | the cenns-10 liquid argon detector to measure cevns at the spallation neutron source |
the experimental data from quasi-elastic electron scattering from <mml:mprescripts></mml:mprescripts>12c are reanalyzed in terms of a new scaling variable suggested by the interacting relativistic fermi gas with scalar and vector interactions, which is known to generate a relativistic effective mass for the interacting nucleons. by choosing a mean value of this relativistic effective mass mn*=0.8 mn , we observe that most of the data fall inside a region around the inverse parabola-shaped universal scaling function of the relativistic fermi gas. this suggests a method to select the subset of data that highlight the quasi-elastic region, about two thirds of the total 2500 data. regardless of the momentum and energy transfer, this method automatically excludes the data that are not dominated by the quasi-elastic process. the resulting band of data reflects deviations from perfect universality and can be used to characterize experimentally the quasi-elastic peak, despite the manifest scaling violation. moreover, we show that the spread of the data around the scaling function can be interpreted as genuine fluctuations of the effective mass m*≡mn*/mn∼0.8 ±0.1 . applying the same procedure we transport the scaling quasi-elastic band into a theoretical prediction band for the neutrino-scattering cross section that is compatible with the recent measurements and slightly more accurate. | scaling violation and relativistic effective mass from quasi-elastic electron scattering: implications for neutrino reactions |
we discuss the main limitations of past neutrino scattering experiments and possible ways to address them in a next-generation program of precision measurements of fundamental interactions with (anti)neutrinos. a reduction of the longstanding precision gap with respect to electron scattering experiments could provide interesting synergies with the existing efforts in the fixed-target, collider, and nuclear physics communities. | precision measurements of fundamental interactions with (anti)neutrinos |
electroweak second order shifts of muonium ($\mu^+e^-$ bound state) energy levels are calculated for the first time. calculation starts from on-shell one-loop elastic $\mu^+ e^-$ scattering amplitudes in the center of mass frame, proceed to renormalization and to derivation of muonium matrix elements by using the momentum space wave functions. this is a reliable method unlike the unjustified four-fermi approximation in the literature. corrections of order $\alpha g_f$ (with $\alpha \sim 1/137$ the fine structure constant and $g_f$ the fermi constant) and of order $\alpha g_f /(m_z a_b)$ (with $m_z$ the z boson mass and $a_b$ the bohr radius) are derived from three classes of feynman diagrams, z self-energy, vertex and box diagrams. the ground state muonium hyperfine splitting is given in terms of the only experimentally unknown parameter, the smallest neutrino mass. it is however found that the neutrino mass dependence is very weak, making its detection difficult. | precision electroweak shift of muonium hyperfine splitting |
we study a dark matter (dm) model in which the dominant coupling to the standard model occurs through a neutrino-dm-scalar coupling. the new singlet scalar will generically have couplings to nuclei/electrons arising from renormalizable higgs portal interactions. as a result, the dm particle x can convert into a neutrino via scattering on a target nucleus n : x +n →ν +n , leading to striking signatures at direct detection experiments. similarly, dm can be produced in neutrino scattering events at neutrino experiments: ν +n →x +n , predicting spectral distortions at experiments such as coherent. furthermore, the model allows for late kinetic decoupling of dark matter with implications for small-scale structure. at low masses, we find that coherent and late kinetic decoupling produce the strongest constraints on the model, while at high masses the leading constraints come from dm down-scattering at xenon1t and borexino. future improvement will come from ce ν ns data, ultralow threshold direct detection, and rare kaon decays. | dark matter-neutrino interconversion at coherent, direct detection, and the early universe |
we consider a scenario in which dark matter particles are accelerated to semi-relativistic velocities through their scattering with the diffuse supernova neutrino background. such a subdominant, but more energetic dark matter component can be then detected via its scattering on the electrons and nucleons inside direct detection experiments. this opens up the possibility to probe the sub-gev mass range, a region of parameter space that is usually not accessible at such facilities. we analyze current data from the xenonnt and lux-zeplin experiments and we obtain novel constraints on the scattering cross sections of sub-gev boosted dark matter with both nucleons and electrons. we also highlight the importance of carefully taking into account earth's attenuation effects as well as the finite nuclear size into the analysis. by comparing our results to other existing constraints, we show that these effects lead to improved and more robust constraints. | xenonnt and lux-zeplin constraints on dsnb-boosted dark matter |
we present an attempt using the maximum entropy principle to determine valence quark distributions in the proton at a very low resolution scale q02. the initial three valence quark distributions are obtained with limited dynamical information from quark model and qcd theory. valence quark distributions from this method are compared to the lepton deep inelastic scattering data, and the widely used ct10 and mstw08 data sets. the obtained valence quark distributions are consistent with experimental observations and the latest global fits of parton distribution functions. the maximum entropy method is expected to be particularly useful in cases where relatively little information from qcd theory is given. | valence quark distributions of the proton from maximum entropy approach |
we present the first fully differential predictions for tau neutrino scattering in the energy region relevant to the dune experiment, including all spin correlations and all tau lepton decay channels. the calculation is performed using a generic interface between the neutrino event generator achilles and the publicly available, general-purpose collider event simulation framework sherpa. | tau polarization and correlated decays in neutrino experiments |
a search for physics beyond the standard model (sm) in the final state with a hadronically decaying tau lepton and a neutrino is presented. this analysis is based on data recorded by the cms experiment from proton-proton collisions at a center-of-mass energy of 13 tev at the lhc, corresponding to a total integrated luminosity of 138 fb−1. the transverse mass spectrum is analyzed for the presence of new physics. no significant deviation from the sm prediction is observed. limits are set on the production cross section of a w' boson decaying into a tau lepton and a neutrino. lower limits are set on the mass of the sequential sm-like heavy charged vector boson and the mass of a quantum black hole. upper limits are placed on the couplings of a new boson to the sm fermions. constraints are put on a nonuniversal gauge interaction model and an effective field theory model. for the first time, upper limits on the cross section of t-channel leptoquark (lq) exchange are presented. these limits are translated into exclusion limits on the lq mass and on its coupling in the t-channel. the sensitivity of this analysis extends into the parameter space of lq models that attempt to explain the anomalies observed in b meson decays. the limits presented for the various interpretations are the most stringent to date. additionally, a model-independent limit is provided. | search for new physics in the τ lepton plus missing transverse momentum final state in proton-proton collisions at √{s } = 13 tev |
a search for supersymmetric particles produced in the vector boson fusion topology in proton-proton collisions is presented. the search targets final states with one or zero leptons, large missing transverse momentum, and two jets with a large separation in rapidity. the data sample corresponds to an integrated luminosity of 35.9 fb-1 of proton-proton collisions at √{s} = 13 tev collected in 2016 with the cms detector at the lhc. the observed dijet invariant mass and lepton-neutrino transverse mass spectra are found to be consistent with the standard model predictions. upper limits are set on the cross sections for chargino ({\tilde{χ}}_1^{±}) and neutralino ({\tilde{χ}}_2^0) production with two associated jets. for a compressed mass spectrum scenario in which the {\tilde{χ}}_1^{± } and {\tilde{χ}}_2^0 decays proceed via a light slepton and the mass difference between the lightest neutralino {\tilde{χ}}_1^0 and the mass-degenerate particles {\tilde{χ}}_1^{± } and {\tilde{χ}}_2^0 is 1 (30) gev, the most stringent lower limit to date of 112 (215) gev is set on the mass of these latter two particles. [figure not available: see fulltext.] | search for supersymmetry with a compressed mass spectrum in the vector boson fusion topology with 1-lepton and 0-lepton final states in proton-proton collisions at √{s} = 13 tev |
we present a global analysis of the inclusive quasielastic electron scattering data with a superscaling approach with relativistic effective mass. the susam* model exploits the approximation of factorization of the scaling function f*(ψ*) out of the cross section under quasifree conditions. our approach is based on the relativistic mean field theory of nuclear matter where a relativistic effective mass for the nucleon encodes the dynamics of nucleons moving in presence of scalar and vector potentials. both the scaling variable ψ* and the single nucleon cross sections include the effective mass as a parameter to be fitted to the data alongside the fermi momentum kf. several methods to extract the scaling function and its uncertainty from the data are proposed and compared. the model predictions for the quasielastic cross section and the theoretical error bands are presented and discussed for nuclei along the periodic table from a =2 to a =238 : 2h, 3h, 3he, 4he, 12c, 6li, 9be, 24mg, 59ni, 89y, 119sn, 181ta, 186w, 197au, 16o, 27al, 40ca, 48ca, 56fe, 208pb, and 238u. we find that more than 9 000 of the total ≈20 000 data fall within the quasielastic theoretical bands. predictions for 48ti and 40ar are also provided for the kinematics of interest to neutrino experiments. | global superscaling analysis of quasielastic electron scattering with relativistic effective mass |
we update the leading order in αs qcd amplitude for deep exclusive neutrino and antineutrino production of a light meson on an unpolarized nucleon. the factorization theorems of the collinear qcd approach allow us to write the amplitude as the convolution of generalized parton distributions and perturbatively calculable coefficient functions. we study both the pseudoscalar-meson and longitudinally polarized vector-meson cases. it turns out that, contrarily to the electroproduction case, the leading-twist scattering amplitudes for π and ρl productions are proportional to one another, which may serve as an interesting new test of the leading-twist dominance of exclusive processes at medium scale. the importance of the gluonic contribution to most cross sections is stressed. | hard exclusive neutrino production of a light meson |
a large experimental program is underway to extend the sensitivity of direct detection experiments, searching for interaction of dark matter with nuclei, down to the neutrino floor. however, such experiments are becoming increasingly difficult and costly due to the large target masses and exquisite background rejection needed for the necessary improvements in sensitivity. we investigate an alternative approach to the detection of dark matter-nucleon interactions: searching for the persistent traces left by dark matter scattering in ancient minerals obtained from much deeper than current underground laboratories. we estimate the sensitivity of paleo-detectors, which extends far beyond current upper limits for a wide range of dark matter masses. the sensitivity of our proposal also far exceeds the upper limits set by snowden-ifft et al. more than three decades ago using ancient mica in an approach similar to paleo-detectors. | searching for dark matter with paleo-detectors |
neutron capture-induced nuclear recoils have emerged as an important tool for detector calibrations in direct dark matter detection and coherent elastic neutrino-nucleus scattering (ce${\nu}$ns). $\texttt{nrcascadesim}$ is a command-line tool for generating simulation data for energy deposits resulting from neutron capture on pure materials. presently, silicon, germanium, neon, and argon are supported. while the software was developed for solid state detector calibration, it can be used for any application which requires simulated neutron capture-induced nuclear recoil data. | `nrcascadesim` - a simulation tool for nuclear recoil cascades resulting from neutron capture |
reactor neutrino experiments provide a rich environment for the study of axionlike particles (alps). using the intense photon flux produced in the nuclear reactor core, these experiments have the potential to probe alps with masses below 10 mev. we explore the feasibility of these searches by considering alps produced through primakoff and compton-like processes as well as nuclear transitions. these particles can subsequently interact with the material of a nearby detector via inverse primakoff and inverse compton-like scatterings, via axio-electric absorption, or they can decay into photon or electron-positron pairs. we demonstrate that reactor-based neutrino experiments have a high potential to test alp-photon couplings and masses, currently probed only by cosmological and astrophysical observations, thus providing complementary laboratory-based searches. we furthermore show how reactor facilities will be able to test previously unexplored regions in the ∼mev alp mass range and alp-electron couplings of the order of gaee ∼ 10−8 as well as alp-nucleon couplings of the order of gann(1 ) ∼ 10−9, testing regions beyond texono and borexino limits. | axionlike particles searches in reactor experiments |
we consider a local u(1) b- lextension of zee-babu model to explain the recently observed 3.5 kev x-ray line signal. the model has three standard model (sm)-singlet dirac fermions with different u(1) b- lcharges. a complex scalar field charged under u(1) b- lis introduced to break the u(1) b- lsymmetry. after u(1) b- lsymmetry breaking a remnant discrete symmetry stabilizes the lightest state of the dirac fermions, which can be a stable dark matter (dm). the second lightest state, if mass splitting with the stable dm is about 3.5 kev, decays dominantly to the stable dm and 3.5 kev photon through two-loop diagrams, explaining the x-ray line signal. two-loop suppression of the decay amplitude makes its lifetime much longer than the age of the universe and it can be a decaying dm candidate in large parameter region. we also introduce a real scalar field which is singlet under both the sm and u(1) b- land can explain the current relic abundance of the dirac fermionic dms. if the mixing with the sm higgs boson is small, it does not contribute to dm direct detection. the main contribution to the scattering of dm off atomic nuclei comes from the exchange of u(1) b- lgauge boson, z ', and is suppressed below current experimental bound when z' mass is heavy (≳10 tev). if the singlet scalar mass is about 0.1-10 mev, dm self-interaction can be large enough to solve small scale structure problems in simulations with the cold dm, such as, the core-vs-cusp problem and too-big-to-fail problem. | 3.5 kev x-ray line signal from dark matter decay in local u(1) b- lextension of zee-babu model |
open neutrino physics issues require precision studies, both theoretical and experimental ones, and towards this aim coherent neutral current neutrino-nucleus scattering events are expected to be observed soon. in this work, we explore $\nu$-nucleus processes from a nuclear theory point of view and obtain results with high confidence level based on accurate nuclear structure cross sections calculations. besides cross sections, the present study includes simulated signals expected to be recorded by nuclear detectors, differential event rates as well as total number of events predicted to be measured. our original cross sections calculations are focused on measurable rates for the standard model process, but we also perform calculations for various channels of the non-standard neutrino-nucleus reactions and come out with promising results within the current upper limits of the corresponding exotic parameters. we concentrate on the possibility of detecting (i) supernova neutrinos by using massive detectors like those of the gerda and supercdms dark matter experiments and (ii) laboratory neutrinos produced near the spallation neutron source facilities (at oak ridge national lab) by the coherent experiment. our nuclear calculations take advantage of the relevant experimental sensitivity and employ the severe bounds extracted for the exotic parameters entering the lagrangians of various particle physics models and specifically those resulting from the charged lepton flavour violating $\mu^{-} \rightarrow e^{-}$ experiments (mu2e and comet experiments). | standard and non-standard neutrino-nucleus reactions cross sections and event rates to neutrino detection experiments |
coherent elastic neutrino-nucleus scattering (ce$\nu$ns) has the largest predicted cross-section of all low-energy neutrino couplings. however, as a neutral-current interaction, the only experimental signature of ce$\nu$ns is a low-energy nuclear recoil, which made its detection challenging. ce$\nu$ns remained unobserved for over four decades. this thesis describes the experiment that resulted in a ce$\nu$ns observation at a 6.7-sigma confidence level. 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 ce$\nu$ns signatures in energy and time, compatible with predictions from the standard model, were observed in high signal-to-background conditions. ce$\nu$ns provides new opportunities to study neutrino properties, and enables the miniaturization of detectors. | first observation of coherent elastic neutrino-nucleus scattering |
we study radiative corrections to neutron beta decay and low-energy (anti)neutrino-nucleon scattering within a top-down effective field theory approach. as it was recently shown, a few electromagnetic and electroweak low-energy coupling constants in heavy-baryon chiral perturbation theory are yet to be determined. performing matching to the four-fermion effective field theory, we relate these low-energy constants to correlation functions of vector and axial-vector currents. such relations allow us to explicitly clarify scheme dependence for radiative corrections to neutron decay and low-energy charged-current (anti)neutrino scattering, provide a robust prediction of leading in the electromagnetic coupling constant contributions, and achieve a clear separation between short-distance and long-distance contributions. | radiative corrections to neutron beta decay and (anti)neutrino-nucleon scattering from low-energy effective field theory |
the deep underground neutrino experiment (dune) will be the next generation long-baseline neutrino experiment. the far detector is designed as a complex of four lar-tpc (liquid argon time projection chamber) modules with 17 kt of liquid argon each. the development and validation of the first far detector technology is pursued through protodune single phase (protodune-sp), a 770 t lar-tpc at cern neutrino platform. crucial in dune is the photon detection system that will ensure the trigger of non-beam events - proton decay, supernova neutrino burst and bsm searches - and will improve the timing and calorimetry for neutrino beam events. doping liquid argon with xenon is a known technique to shift the light emitted by argon (128 nm) to a longer wavelength (178 nm) to ease its detection. the largest xenon doping test ever performed in a lar-tpc was carried out in protodune-sp. from february to may 2020, a gradually increasing amount of xenon was injected to also compensate for the light loss due to air contamination. the response of such a large tpc has been studied using the protodune-sp photon detection system (pds) and a dedicated setup installed before the run. with the first it was possible to study the light collection efficiency with respect to the track position, while with the second it was possible to distinguish the xenon light (178 nm) from the lar light (128 nm). the light shifting mechanism proved to be highly efficient even at small xenon concentrations (<20 ppm in mass) furthermore it allowed recovering the light quenched by pollutants. the light collection improved far from the detection plane, enhancing the photon detector response uniformity along the drift direction and confirming a longer rayleigh scattering length for 178 nm photons, with respect to 128 nm ones. the charge collection by the tpc was monitored proving that xenon up to 20 ppm does not impact its performance. | xenon doping of liquid argon in protodune single phase |
this article summarizes the state of the art of νμ and ν¯μ cc 0 π cross-section measurements on carbon and argon and discusses the relevant nuclear models, parametrizations and uncertainties in genie v3. the cc 0 π event topology is common in experiments at a few-gev energy range. although its main contribution comes from quasielastic interactions, this topology is still not well understood. the genie global analysis framework is exploited to analyze cc 0 π datasets from miniboone, t2k and miner ν a . a partial tune for each experiment is performed, providing a common base for the discussion of tensions between datasets. the results offer an improved description of nuclear cc 0 π datasets as well as data-driven uncertainties for each experiment. this work is a step towards a genie global tune that improves our understanding of neutrino interactions on nuclei. it follows from earlier genie work on the analysis of neutrino scattering datasets on hydrogen and deuterium. | neutrino-nucleus cc 0 π cross-section tuning in genie v3 |
the production of w and z bosons in association with jets is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 tev by the lhcb experiment, corresponding to an integrated luminosity of 1.98 ± 0.02 fb-1. the w boson is identified using its decay to a muon and a neutrino, while the z boson is identified through its decay to a muon pair. total cross-sections are measured and combined into charge ratios, asymmetries, and ratios of w +jet and z+jet production cross-sections. differential measurements are also performed as a function of both boson and jet kinematic variables. all results are in agreement with standard model predictions. [figure not available: see fulltext.] | measurement of forward w and z boson production in association with jets in proton-proton collisions at √{s}=8 tev |
the probability of large-angle scattering for multi-gev muons in lead targets with a thickness of o(10 - 1) radiation lengths is studied. the new estimates presented here are based both on simulation programs (geant4 libraries) and theoretical calculations. in order to validate the results provided by simulation, a comparison is drawn with experimental data from the literature. this study is particularly relevant when applied to muons originating from νμ cc interactions of cngs beam neutrinos. in that circumstance the process under study represents the dominant background for the νμ → ντ search in the τ→ μ channel for the opera experiment at lngs. finally we also investigate, in the cngs context, possible contributions from the muon photo-nuclear process which might in principle also produce a large-angle muon scattering signature in the detector. | large-angle scattering of multi-gev muons on thin lead targets |
constraints on couplings of several beyond-standard-model-physics scenarios, mediated by massive intermediate particles including (1) an extra z-prime, (2) a new light spin-1 boson, and (3) a charged higgs boson, are placed via the neutrino-electron scattering channel to test the standard model at a low energy-momentum transfer regime. data on ν¯e-e and νe-e scattering from the texono and lsnd, respectively, are used. upper bounds to coupling constants of the flavor-conserving and flavor-violating new light spin-1 boson and the charged higgs boson with respect to different mediator masses are determined. the relevant parameter spaces are extended by allowing light mediators. new lower mass limits for extra z-prime gauge boson models are also placed. | constraints on nonstandard intermediate boson exchange models from neutrino-electron scattering |
in neutrino-nucleus interactions, a proton produced with a correlated pion might exhibit a left-right asymmetry relative to the lepton scattering plane even when the pion is absorbed. absent in other proton production mechanisms, such an asymmetry measured in charged-current pionless production could reveal the details of the absorbed-pion events that are otherwise inaccessible. in this study, we demonstrate the idea of using final-state proton left-right asymmetries to quantify the absorbed-pion event fraction and underlying kinematics. this technique might provide critical information that helps constrain all underlying channels in neutrino-nucleus interactions in the gev regime. | pion-proton correlation in neutrino interactions on nuclei |
this work presents a sensitivity study of a reactor liquid scintillator detector to three kinds of dark bosons with masses below 1 mev, such as dark photons, axion-like particles, and light scalar bosons. the juno-tao detector with taishan nuclear reactor is taken as a reference. with a proposed 180 days of data taking, the best sensitivity result at the level of ∼10-5 95% c.l. is achieved for dark photons with an optimized signal to background ratio for the electron coupling constant gx through inverse compton-like scattering. similar calculations are completed for axion-like particles and scalar bosons. the background systematic uncertainty presents as the main limiting factor for the further sensitivity improvement. several remarks are made to the controversial analysis for the neos experiment. additionally the differential and the inverse differential cross sections have been derived for all three boson types and their interactions with electrons in liquid scintillator. | light dark bosons in the juno-tao neutrino detector |
in this article, we reevaluate supernovae (sn) constraints on the diffusion time of neutrinos for a family of extensions of the standard model that incorporate new light scalar and vector mediators. we compute the neutrino mean free path, taking into account medium effects in the neutrino-nucleon scattering cross section, and a radial dependence of the density, energy, and temperature inside the proto-neutron star to determine the coupling strengths compatible with sn1987a constraints on the time duration signal of diffusing neutrinos. we show that medium effects can induce an order of magnitude enhancement in the neutrino mean free path with respect to the vacuum calculation. the increase is more significant when new physics terms dominate over the standard model contribution (that is, for small mediator mass and large couplings). finally, we interpret these results as bounds on the parameter space of a vector u (1 )b-l model and scalar lepton number conserving and lepton number violating scenarios, improving on previous results in the literature where medium effects were ignored. we show that sn constraints on the neutrino diffusion time lie within regions of the parameter space that are already ruled out by other experimental constraints. we also comment on potential limits due to changes in the sn equation of state or right-handed neutrino free-streaming, but argue that detailed numerical simulations are needed to improve the reliability of these limits. | medium effects in supernovae constraints on light mediators |
in this paper we work in the framework of a radiative seesaw model with triplet fermion σ. due to the z2 discrete flavor symmetry, the lightest neutral component of σ is stable and thus can be a dark matter candidate. its mass can be solely determined by the dark matter relic abundance, which is bout 2.594 tev. it can still constitute 30% of the dark matter when considering constraints from dark matter indirect detection experiments. the model also predict a dark matter-nucleus scattering cross-section that would be accessible with future dark matter direct detection searches. we further investigate constraints on the parameter space of the model from the lepton-flavor-violating processes and neutrino transition magnetic moments, induced by the yukawa interaction of the σ with the left-handed lepton doublets. | dark matter, lfv and neutrino magnetic moment in the radiative seesaw model with fermion triplet |
we present recent results on the first experimental observation of the coherent elastic scattering of the neutrino on atomic nuclei and review other experiments related to the detection and investigation of this process. | coherent elastic neutrino scattering on atomic nucleus: recently discovered type of low-energy neutrino interaction |
taking into account recent theoretical and experimental inputs on reactor fluxes we reconsider the determination of the weak mixing angle from low energy experiments. we perform a global analysis to all available neutrino-electron scattering data from reactor antineutrino experiments, obtaining sin2 θw = 0.252 ± 0.030. we discuss the impact of the new theoretical prediction for the neutrino spectrum, the new measurement of the reactor antineutrino spectrum by the daya bay collaboration, as well as the effect of radiative corrections. we also reanalyze the measurements of the νe - e cross section at accelerator experiments including radiative corrections. by combining reactor and accelerator data we obtain an improved determination for the weak mixing angle, sin2 θw = 0.254 ± 0.024. | the weak mixing angle from low energy neutrino measurements: a global update |
the measurement of muon momentum by multiple coulomb scattering is a crucial ingredient to the reconstruction of νμ cc events in the icarus-t600 liquid argon tpc in absence of magnetic field, as in the search for sterile neutrinos at fermilab where icarus will be exposed to ~ 1 gev booster neutrino beam. a sample of ~ 1000 stopping muons produced by charged current interactions of cngs νμin the surrounding rock at the infn gran sasso underground laboratory provides an ideal benchmark in the few-gev range since their momentum can be directly and independently obtained by the calorimetric measurement. stopping muon momentum in the 0.5-4.5 gev/c range has been reconstructed via multiple coulomb scattering with resolution ranging from 10 to 25% depending on muon energy, track length and uniformity of the electric field in the drift volume. | muon momentum measurement in icarus-t600 lar-tpc via multiple scattering in few-gev range |
we propose a fully non-perturbative method to compute inelastic lepton-nucleon ($\ell n$) scattering cross sections using lattice qcd. the method is applicable even at low energies, such as the energy region relevant for the recent and future neutrino-nucleon ($\nu n$) scattering experiments, for which perturbative analysis is invalidated. the basic building block is the forward compton-scattering amplitude, or the hadronic tensor, computed on a euclidean lattice. total cross section is constructed from the hadronic tensor by multiplying a phase space factor and integrating over the energy and momentum of final hadronic states. the energy integral that induces a sum over all possible final states is performed implicitly by promoting the phase space factor to an operator written in terms of the transfer matrix on the lattice. the formalism is imported from that of the inclusive semileptonic b meson decay [p. gambino, s. hashimoto, arxiv:2005.13730]. it can be generalized to compute the $\ell n$ scattering cross sections and their moments, as well as the virtual correction to the nuclear $\beta$-decay. necessary quark-line contractions for two current insertions corresponding to the compton amplitude to be computed on the lattice are summarized. | towards fully non-perturbative computation of inelastic $\\ell n$ scattering cross sections from lattice qcd |
neutrino-electron scattering is a purely leptonic fundamental interaction and therefore provides an important channel to test the standard model, especially at the low energy-momentum transfer regime. we derived constraints on neutrino nonstardard interaction couplings depending on model-independent approaches which are described by a four-fermi pointlike interaction and the unparticle physics model with tensorial components. data on ν¯ e-e and νe-e scattering from the texono and lsnd experiments, respectively, are used. the upper limits and the allowed regions of scalar, pseudoscalar, and tensorial nonstandard interaction couplings of neutrinos are derived at 90% confidence level in both one-parameter and two-parameter analysis. new upper limits for tensorial unparticle physics coupling constants and mass parameters are also placed. | constraints on scalar-pseudoscalar and tensorial nonstandard interactions and tensorial unparticle couplings from neutrino-electron scattering |
effects of neutrino charge radius and magnetic moment constraints obtained from the astrophysical observations and reactor experiments, as well as in-medium modifications of the weak and electromagnetic nucleon form factors of the matter on the neutrino electroweak interaction with dense matter, are estimated. we use a relativistic mean-field model for the in-medium effective nucleon mass and quark-meson coupling model for nucleon form factors. we analyze the neutrino scattering cross section and mean free path in cold nuclear matter. we find that the increase of the cross section relative to that without neutrino form factors results in the decrease of the neutrino mean free path when neutrino form factors and the in-medium modifications of the nucleon weak and electromagnetic form factors are simultaneously considered. the quenching of the neutrino mean free path is evaluated to be about 12-58% for the values of μν = 3 ×10-12μb and rν = 3.5 ×10-5mev-1 compared with that obtained for the μν = 0 and rν = 0. the decrease of the neutrino mean free path is expected to decelerate the cooling of neutron stars. each contribution of the neutrino form factors to the neutrino mean free path is discussed. | effects of neutrino magnetic moment and charge radius constraints and medium modifications of the nucleon form factors on the neutrino mean free path in dense matter |
we compare the results of the relativistic green's function model with the experimental data of the charged-current inclusive differential neutrino-nucleus cross sections published by the t2k collaboration. the model, which is able to describe both miner ν a and miniboone charged-current quasielastic scattering data, underpredicts the inclusive t2k cross sections. | relativistic green's function model and charged-current inclusive neutrino-nucleus scattering at t2k kinematics |
the wimp-nucleon scattering cross section in a simple dark matter model and its constraints from the latest direct detection experiment are treated here at the loop level. we consider a scenario with an emerging vector dark matter field that interacts with the standard model quarks, via loop contributions that are sourced from a scalar mediator. the involved parameter space for the dark matter-mediator masses is constrained by the xenon1t limit and the neutrino floor. the current direct detection bounds are eluded by invoking the top partners in a composite higgs model, whose scale mass helps us in suppressing the wimp-nucleon cross section. | top partners tackling vector dark matter |
we investigate the sensitivity of the faser$\nu$ detector, a novel experimental setup at the lhc, to probe and constrain generalized neutrino interactions (gni). employing a comprehensive theoretical framework, we model the effects of generalized neutrino interactions on neutrino-nucleon deep inelastic scattering processes within the faser$\nu$ detector. by considering all the neutrino channels produced at the lhc, we perform a statistical analysis to determine the sensitivity of faser$\nu$ to constrain these interactions. our results demonstrate that faser$\nu$ can place stringent constraints on the gni effective couplings. additionally, we study the relation between gni and a minimal leptoquark model where the sm is augmented by a singlet leptoquark with hypercharge $1/3$. we have found that the sensitivities for various combinations of the leptoquark yukawa couplings are approximately $\mathcal{o}(1)$, particularly when considering a leptoquark mass in the tev range. | examining the sensitivity of faser to generalized neutrino interactions |
we explore the dark matter phenomenology of a weak-scale right-handed neutrino in the context of a two higgs doublet model. the expected signal at direct detection experiments is different from the usual spin-independent and spin-dependent classification since the scattering with quarks depends on the dark matter spin. the dark matter relic density is set by thermal freeze-out and in the presence of non-standard cosmology, where an abelian gauge symmetry is key for the dark matter production mechanism. we show that such symmetry allows us to simultaneously address neutrino masses and the flavor problem present in general two higgs doublet model constructions. lastly, we outline the region of parameter space that obeys collider, perturbative unitarity and direct detection constraints. | right-handed neutrino dark matter, neutrino masses, and non-standard cosmology in a 2hdm |
several indications for neutral scalars are observed at the lhc. one of them, a broad resonance peaked at about 650 gev which we call h(650), was first observed by an outsider combining published histograms from atlas and cms on zz -> 4 leptons searches, and this combination shows a local significance close to 4 s.d. since then, cms has reported two other indications at the same mass, with similar local significances: h->ww->2leptons+neutrinos and h(650)->bbh(125) where mbb~90 gev and h(125)->gam gam. atlas has completed its analysis of zz->4 leptons from which we infer an indication for h(650) with 3.5 s.d. significance. assuming that the mass is already known from the former set, and combining these three results, one gets a global statistical significance above 6 s.d. h(650) has a coupling to ww similar to h(125) and therefore we argue that a sum rule (sr) required by unitarity for w+w- scattering implies that there should be a compensating effect from a doubly charged scalar h++, with a large coupling to w+w+. we therefore predict that this mode should become visible through the vector boson fusion process w+w+->h++, naturally provided by lhc. a recent indication for h++(450)->w+w+ from atlas allows a model independent interpretation of this result through the sr constraint which gives br(h++->w+w+)~10%, implying the occurrence of additional decay modes h+w+ and h+h+ from one or several light h+ with masses below mh++ - mw or mh++/2, that is mh+ < 370 gev or 225 gev. a similar analysis is performed for h+(375)->zw, indicated by atlas and cms. both channels suggest a scalar field content similar to the georgi machacek model with triplets, at variance with the models usually considered. an alternate interpretation of the 650 gev resonance as a tensor is also briefly discussed. implications for precision measurements are presented. | h(650) -> w+w-/zz predicts h++ -> w+w+ and h+ -> zw+, as indicated by lhc data |
in order to better understand the emc effect, we propose a clean and precise measurement of the flavor dependence of the emc effect using parity-violating deep inelastic scattering on a 48ca target. this measurement will provide an extremely sensitive test for flavor dependence in the modification of nuclear parton distribution functions (pdfs) for neutron-rich nuclei. a measurement of the flavor dependence will provide new and vital information and help to explain nucleon modification at the quark level. in addition to helping understand the origin of the emc effect, a flavor-dependent nuclear pdf modification could significantly impact a range of processes, including neutrino-nucleus scattering, nuclear drell-yan processes, and e-a observables at the electron-ion collider. the parity-violating asymmetry apv from 48ca using an 11 gev beam at 80 μ a will be measured using the solid detector, proposed for a series of measurements in hall a at jefferson lab. in 68 days of data taking, we will reach 0.7-1.3% statistical precision for 0.2 <x <0.7 with 0.6-0.7% systematic uncertainties. the goal is to make the first direct measurement of the flavor dependence of the emc effect. the precision of the measurement will allow for quantification of the flavor-dependent effects, greatly improving our ability to differentiate between models of the emc effect and constraining the u- and d-quark contributions in neutron rich nuclei. | pvemc: isolating the flavor-dependent emc effect using parity-violating inelastic scattering in solid |
the japan proton accelerator research complex (j-parc) is a hadron-accelerator facility that aims to provide secondary beams of kaons, pions, neutrinos, muons, and others together with the primary proton beam for investigating a wide range of science projects. high-energy hadron physics can be studied by using high-momentum beams of unseparated hadrons, which are essentially pions, and also primary protons. in this report, possible experiments are explained on color transparency and generalized parton distributions (gpds). these projects are complementary to lepton-scattering experiments at jefferson laboratory (jlab), compass/amber, and future electron-ion colliders. thank to hadron-beam energies up to 30 gev, j-parc is a unique facility to investigate the transition region from the hadron degrees of freedom to the quark-gluon degrees of freedom. it is suitable for finding mechanisms of the olor transparency. such color-transparency studies are also valuable for clarifying the factorization of hadron production processes in extracting the gpds from actual measurements. these studies will lead to the understanding of basic high-energy hadron interactions in nuclear medium and to clarifications on the origins of hadron spins, masses, and internal pressure mechanisms. | j-parc hadron physics and future possibilities on color transparency |
a sample of two-proton and no-pion events selected in the argoneut neutrino scattering experiment on a liquid argon target [phys. rev. d 90, 012008 (2014), 10.1103/physrevd.90.012008] is analyzed with the nuwro monte carlo event generator. an attempt is made to estimate how likely it is to obtain observed numbers of laboratory frame and reconstructed back-to-back nucleon pairs. for laboratory frame back-to-back events, a clear data/monte carlo discrepancy is seen. for the reconstructed nucleon pairs, a good agreement is reported. we provide a simple kinematical argument that explains why this accordance is expected. | search for nucleon-nucleon correlations in neutrino-argon scattering |
observations of suspected coherent elastic neutrino-nucleus scatterings by dark matter direct detection experiments highlight the need for an investigation into the so-called "neutrino floor." we focus on the discovery limit, a statistical concept to identify the neutrino floor, and analyze the asymptotic behavior of the profile binned likelihood ratio test statistic where the likelihood is constructed by variate from events in each bin and pull terms from neutrino fluxes. to achieve the asymptotic result, we propose two novel methods: (i) the asymptotic-analytic method, which furnishes the analytic result for large statistics, is applicable for more extra nuisance parameters, and enables the identification of the most relevant parameters in the statistical analysis; (ii) the quasi-asimov dataset, which is analogous to the asimov dataset but with improved speed. applying our methods to the neutrino floor, we significantly accelerate the computation procedure compared to the previous literature, and successfully address cases where the asimov dataset fails. our derivation on the asymptotic behavior of the test statistic not only facilitates research into the impact of neutrinos on the search for dark matter, but may also prove relevant in similar application scenarios. | asymptotic analysis of binned likelihoods and the neutrino floor |
we consider the resonant production and detection of charged mesons in existing and near-future neutrino scattering experiments with eν≲1 tev , characteristic of high-energy atmospheric neutrinos or collider-sourced neutrino beams. the most promising candidate is the reaction ν¯ee-→ρ-→π-π0. we discuss detection prospects at faser ν , the lhc's forward physics facility with nuclear emulsion (faser ν 2 ) and liquid argon detectors (flare), and we estimate the number of expected resonance-mediated events in the existing data set of icecube. we also outline possible detection strategies for the different experimental environments. we predict dozens of events at the forward physics facility and identify cuts with order-one signal efficiency that could potentially suppress backgrounds at faser ν , yielding a signal-to-background ratio larger than 1. antineutrino-induced s -channel meson resonances are yet unobserved standard model scattering processes which offer a realistic target for near-term experiments. | resonances in ν¯e-e- scattering below a tev |
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