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the large and growing library of measurements from the large hadron collider has significant power to constrain extensions of the standard model. we consider such constraints on a well-motivated model involving a gauged and spontaneously-broken b - l symmetry, within the c ontur framework. the model contains an extra higgs boson, a gauge boson, and right-handed neutrinos with majorana masses. this new particle content implies a varied phenomenology highly dependent on the parameters of the model, very well-suited to a general study of this kind. we find that existing lhc measurements significantly constrain the model in interesting regions of parameter space. other regions remain open, some of which are within reach of future lhc data. | lhc constraints on a b - l gauge model using c ontur |
theoretical predictions for elastic neutrino-electron scattering have no hadronic or nuclear uncertainties at leading order making this process an important tool for normalizing neutrino flux. however, the process is subject to large radiative corrections that differ according to experimental conditions. in this paper, we collect new and existing results for total and differential cross sections accompanied by radiation of one photon, ν e →ν e (γ ). we perform calculations within the fermi effective theory and provide analytic expressions for the electron energy spectrum and for the total electromagnetic energy spectrum as well as for double- and triple-differential cross sections with respect to electron energy, electron angle, photon energy, and photon angle. we discuss illustrative applications to accelerator-based neutrino experiments and provide the most precise up-to-date values of neutrino-electron scattering cross sections. we present an analysis of theoretical error, which is dominated by the ∼0.2 %- 0.4 % uncertainty of the hadronic correction. we also discuss how searches for new physics can be affected by radiative corrections. | theory of elastic neutrino-electron scattering |
a search for a new z' gauge boson associated with (un)broken b -l symmetry in the kev-gev mass range is carried out for the first time using the missing-energy technique in the na64 experiment at the cern sps. from the analysis of the data with 3.22 ×1011 electrons on target collected during 2016-2021 runs, no signal events were found. this allows us to derive new constraints on the z'-e coupling strength, which, for the mass range 0.3 ≲mz'≲100 mev , are more stringent compared to those obtained from the neutrino-electron scattering data. | search for a new b -l z' gauge boson with the na64 experiment at cern |
electroweak symmetry breaking explains the origin of the masses of elementary particles through their interactions with the higgs field. besides the measurements of the higgs boson properties, the study of the scattering of massive vector bosons with spin one allows the nature of electroweak symmetry breaking to be probed. among all processes related to vector-boson scattering, the electroweak production of two jets and a $z$-boson pair is a rare and important one. here we report the observation of this process from proton-proton collision data corresponding to an integrated luminosity of 139/fb recorded at a centre-of-mass energy of 13 tev with the atlas detector at the large hadron collider. we consider two different final states originating from the decays of the $z$-boson pair - one containing four charged leptons and the other containing two charged leptons and two neutrinos. the hypothesis of no electroweak production is rejected with a statistical significance of 5.7 $\sigma$, and the measured cross-section for electroweak production is consistent with the standard model prediction. in addition, we report cross-sections for inclusive production of a $z$-boson pair and two jets for the two final states. | observation of electroweak production of two jets and a $z$-boson pair |
a search for charged higgs boson decaying to a charm and a bottom quark ( {h}+\to c\overline{b} ) is performed using 19.7 fb-1 of pp collision data at √{s}=8 tev. the production mechanism investigated in this search is t\overline{t} pair production in which one top quark decays to a charged higgs boson and a bottom quark and the other decays to a charged lepton, a neutrino, and a bottom quark. charged higgs boson decays to c\overline{b} are searched for, resulting in a final state containing at least four jets, a charged lepton (muon or electron), and missing transverse momentum. a kinematic fit is performed to identify the pair of jets least likely to be the bottom quarks originating from direct top quark decays and the invariant mass of this pair is used as the final observable in the search. no evidence for the presence of a charged higgs boson is observed and upper limits at 95% confidence level of 0.8-0.5% are set on the branching fraction ℬ(t → h+b), assuming ℬ(h+ → c\overline{b} ) = 1 .0 and ℬ(t → h+b) + ℬ(t → wb) = 1 .0, for the charged higgs boson mass range 90-150 gev. [figure not available: see fulltext.] | search for a charged higgs boson decaying to charm and bottom quarks in proton-proton collisions at √{s}=8 tev |
we evaluate and discuss the impact of meson-exchange currents (mecs) on charged-current quasielastic neutrino cross sections. we consider the nuclear transverse response arising from two-particle two-hole states excited by the action of electromagnetic, purely isovector meson-exchange currents in a fully relativistic framework based on the work by the torino collaboration [a. d. pace, m. nardi, w. m. alberico, t. w. donnelly, and a. molinari, nucl. phys. a726, 303 (2003)]. an accurate parametrization of this mec response as a function of the momentum and energy transfers involved is presented. results of neutrino-nucleus cross sections using this mec parametrization together with a recent scaling approach for the one-particle one-hole contributions (named susav2) are compared with experimental data. | meson-exchange currents and quasielastic predictions for charged-current neutrino-12c scattering in the superscaling approach |
we present an overview of recent progress towards the ricochet coherent elastic neutrino nucleus scattering ce$\nu$ns experiment. the ill research reactor in grenoble, france has been selected as the experiment site, after in situ studies of vibration and particle backgrounds. we present background rate estimates specific to that site, along with descriptions of the planned cryocube and q-array detector payloads. | ricochet progress and status |
the lhc produces an intense beam of highly energetic neutrinos of all three flavors in the forward direction, and the forward physics facility (fpf) has been proposed to house a suite of experiments taking advantage of this opportunity. in this study, we investigate the fpf's potential to probe the neutrino electromagnetic properties, including neutrino millicharge, magnetic moment, and charge radius. we find that, due to the large flux of tau neutrinos at the lhc, the fpf detectors will be able to provide the strongest laboratory-based sensitivity to the tau neutrino magnetic moment and millicharge by searching for excess in low recoil energy electron scattering events. we also find that, by precisely measuring the rate of neutral current deep inelastic scattering events, the fpf detectors have the potential to obtain the strongest experimental bounds on the neutrino charge radius for the electron neutrino, and one of the leading bounds for the muon neutrino flavor. the same signature could also be used to measure the weak mixing angle, and we estimate that $\sin^2 \theta_w$ could be measured to about $3\%$ precision at a scale $q \sim 10$ gev, shedding new light on the long-standing nutev anomaly. | neutrino electromagnetic properties and the weak mixing angle at the lhc forward physics facility |
we present a phenomenological study of nuclear effects in neutrino charged-current interactions, using transverse kinematic imbalances in exclusive measurements. novel observables with minimal dependence on neutrino energy are proposed to study quasielastic scattering and especially resonance production. they should be able to provide direct constraints on nuclear effects in neutrino- and antineutrino-nucleus interactions. | measurement of nuclear effects in neutrino interactions with minimal dependence on neutrino energy |
we analyze charged-current electron-neutrino cross sections on carbon. we consider two different theoretical approaches, on one hand the continuum random phase approximation (crpa) which allows a description of giant resonances and quasielastic excitations, on the other hand the rpa-based calculations which are able to describe multinucleon emission and coherent and incoherent pion production as well as quasielastic excitations. we compare the two approaches in the genuine quasielastic channel, and find a satisfactory agreement between them at large energies while at low energies the collective giant resonances show up only in the crpa approach. we also compare electron-neutrino cross sections with the corresponding muon-neutrino ones in order to investigate the impact of the different charged-lepton masses. finally, restricting to the rpa-based approach, we compare the sum of quasielastic, multinucleon emission, coherent, and incoherent one-pion production cross sections (folded with the electron-neutrino t2k flux) with the charged-current inclusive electron-neutrino differential cross sections on carbon measured by t2k. we find a good agreement with the data. the multinucleon component is needed in order to reproduce the t2k electron-neutrino inclusive cross sections. | electron-neutrino scattering off nuclei from two different theoretical perspectives |
the dresden-ii reactor experiment has recently reported a suggestive evidence for the observation of coherent elastic neutrino-nucleus scattering, using a germanium detector. given the low recoil energy threshold, these data are particularly interesting for a low-energy determination of the weak mixing angle and for the study of new physics leading to spectral distortions at low momentum transfer. using two hypotheses for the quenching factor, we study the impact of the data on: (i) the weak mixing angle at a renormalization scale of ~ 10 mev, (ii) neutrino generalized interactions with light mediators, (iii) the sterile neutrino dipole portal. the results for the weak mixing angle show a strong dependence on the quenching factor choice. although still with large uncertainties, the dresden-ii data provide for the first time a determination of sin2θw at such scale using coherent elastic neutrino-nucleus scattering data. tight upper limits are placed on the light vector, scalar and tensor mediator scenarios. kinematic constraints implied by the reactor anti-neutrino flux and the ionization energy threshold allow the sterile neutrino dipole portal to produce up-scattering events with sterile neutrino masses up to ~ 8 mev. in this context, we find that limits are also sensitive to the quenching factor choice, but in both cases competitive with those derived from xenon1t data and more stringent that those derived with coherent data, in the same sterile neutrino mass range. | consequences of the dresden-ii reactor data for the weak mixing angle and new physics |
measurements of the cross sections for top quark pairs produced in association with a w or z boson are presented, using 8 tev pp collision data corresponding to an integrated luminosity of 19.5 fb-1, collected by the cms experiment at the lhc. final states are selected in which the associated w boson decays to a charged lepton and a neutrino or the z boson decays to two charged leptons. signal events are identified by matching reconstructed objects in the detector to specific final state particles from toverline{t}w or toverline{t}z decays. the toverline{t}w cross section is measured to be 382 - 102 + 117 fb with a significance of 4.8 standard deviations from the background-only hypothesis. the toverline{t}z cross section is measured to be 242 - 55 + 65 fb with a significance of 6.4 standard deviations from the background-only hypothesis. these measurements are used to set bounds on five anomalous dimension-six operators that would affect the toverline{t}w and toverline{t}z cross sections. [figure not available: see fulltext.] | observation of top quark pairs produced in association with a vector boson in pp collisions at √{s}=8 tev |
we estimate the sensitivity of the dune experiment to new physics particles interacting with neutrinos, considering the dipole portal to heavy neutral leptons and a neutrinophilic scalar with lepton-number 2 as examples. we demonstrate that neutrinos from the high-energy tail of the dune flux, with energies eν≳5 - 10 gev , may significantly improve the sensitivity to these models, allowing to search for particles as heavy as ≃10 gev . we also study the impact of the so-called tau-optimized neutrino beam configuration, which slightly improves sensitivity to the new physics models considered here. for both models, we consider new production channels (such as deep-inelastic scattering) and provide a detailed comparison of different signatures in the detector. | dipole portal and neutrinophilic scalars at dune revisited: the importance of the high-energy neutrino tail |
the physics reach of a low threshold (100 ev) scintillating argon bubble chamber sensitive to coherent elastic neutrino-nucleus scattering (ce ν ns ) from reactor neutrinos is studied. the sensitivity to the weak mixing angle, neutrino magnetic moment, and a light z' gauge boson mediator are analyzed. a monte carlo simulation of the backgrounds is performed to assess their contribution to the signal. the analysis shows that world-leading sensitivities are achieved with a one-year exposure for a 10 kg chamber at 3 m from a 1 mwt h research reactor or a 100 kg chamber at 30 m from a 2000 mwt h power reactor. such a detector has the potential to become the leading technology to study ce ν ns using nuclear reactors. | physics reach of a low threshold scintillating argon bubble chamber in coherent elastic neutrino-nucleus scattering reactor experiments |
in global analyses of nuclear parton distribution functions (npdfs), neutrino deep-inelastic scattering (dis) data have been argued to exhibit tensions with the data from charged-lepton dis. using the ncteq framework, we investigate these possible tensions both internally and with the datasets used in our recent npdf analysis ncteq15wzsih. we take into account nuclear effects in the calculation of the deuteron structure function f2d using the cj15 analysis. the resulting npdf fit, ncteq15wzsihdeut, serves as the basis for our comparison with inclusive neutrino dis and charm dimuon production data. using χ2 hypothesis testing, we confirm evidence of tensions with these data and study the impact of the proton pdf baseline as well as the treatment of data correlation and normalization uncertainties. we identify the experimental data and kinematic regions that generate the tensions and present several possible approaches how a consistent global analysis with neutrino data can be performed. we show that the tension can be relieved using a kinematic cut at low x (x >0.1 ) and also investigate a possibility of managing the tensions by using uncorrelated systematic errors. finally, we present a different approach identifying a subset of neutrino data which leads to a consistent global analysis without any additional cuts. understanding these tensions between the neutrino and charged-lepton dis data is important not only for a better flavor separation in global analyses of nuclear and proton pdfs, but also for neutrino physics and for searches for physics beyond the standard model. | compatibility of neutrino dis data and its impact on nuclear parton distribution functions |
we compute bounds on coefficients of effective operators in the standard model that can be inferred from observations of neutrino scattering by the coherent experiment. while many operators are bound extremely well by past experiments the full future data set from coherent will provide modest improvements for some operators. | electroweak constraints from the coherent experiment |
a search for physics beyond the standard model (sm) in final states with an electron or muon and missing transverse momentum is presented. the analysis uses data from proton-proton collisions at a centre-of-mass energy of 13 tev, collected with the cms detector at the lhc in 2016-2018 and corresponding to an integrated luminosity of 138 fb−1. no significant deviation from the sm prediction is observed. model-independent limits are set on the production cross section of w' bosons decaying into lepton-plus-neutrino final states. within the framework of the sequential standard model, with the combined results from the electron and muon decay channels a w' boson with mass less than 5.7 tev is excluded at 95% confidence level. results on a sm precision test, the determination of the oblique electroweak w parameter, are presented using lhc data for the first time. these results together with those from the direct w' resonance search are used to extend existing constraints on composite higgs scenarios. this is the first experimental exclusion on compositeness parameters using results from lhc data other than higgs boson measurements. | search for new physics in the lepton plus missing transverse momentum final state in proton-proton collisions at √{s } = 13 tev |
we present results of several measurements of csi[na] scintillation response to 3-60 kev energy nuclear recoils performed by the coherent collaboration using tagged neutron elastic scattering experiments and an endpoint technique. earlier results, used to estimate the coherent elastic neutrino-nucleus scattering (cevns) event rate for the first observation of this process achieved by coherent at the spallation neutron source (sns), have been reassessed. we discuss corrections for the identified systematic effects and update the respective uncertainty values. the impact of updated results on future precision tests of cevns is estimated. we scrutinize potential systematic effects that could affect each measurement. in particular we confirm the response of the h11934-200 hamamatsu photomultiplier tube (pmt) used for the measurements presented in this study to be linear in the relevant signal scale region. | measurement of scintillation response of csi[na] to low-energy nuclear recoils by coherent |
we constrain general dirac neutrino interactions based on the standard model effective field theory framework extended with right-handed neutrinos n (smneft) using deep inelastic and coherent elastic neutrino scattering, nuclear beta decay, and meson decay data, and high energy electron-proton and proton-proton collider data. we compute the one-loop anomalous dimensions of the low-energy effective field theory (left) below the electroweak scale and of smneft above the electroweak scale. the tree-level matching between left and smneft is performed at the electroweak scale. currently, the most stringent limits on scalar and tensor interactions arise from pseudoscalar meson decays and the lhc measurements at the per mille level. in the future, the upcoming high-luminosity lhc (hl-lhc) has the potential to reach the 10-4 level and lhec can play an important role under certain theoretical assumptions. | scalar and tensor neutrino interactions |
in this article we obtain a new set of nuclear parton distribution functions (nuclear pdfs) at next-to-leading order and next-to-next-to-leading order accuracy in perturbative qcd. the common nuclear deep-inelastic scattering (dis) data analyzed in our study are complemented by the available charged-current neutrino dis data with nuclear targets and data from drell-yan cross section measurements for several nuclear targets. in addition, the most recent dis data from the jefferson lab clas and hall c experiments are also added to our data sample. for these specific datasets, we consider the impact of target mass corrections and higher twist effects which are expected to be important in the region of large x and intermediate-to-low q2. our analysis is based on a publicly available open-source tool, apfel, which has been modified to be applicable for our analysis of nuclear pdfs. heavy-quark contributions to nuclear dis are considered within the framework of the fonll general-mass variable-flavor-number scheme. the most recent ct18 pdfs are used as baseline proton pdfs. the uncertainties of nuclear pdfs are determined using the standard hessian approach. the results of our global qcd analysis are compared with existing nuclear pdf sets and with the fitted cross sections, for which our set of nuclear pdfs provides a very good description. | nuclear parton distribution functions with uncertainties in a general mass variable flavor number scheme |
forthcoming fixed-target coherent elastic neutrino-nucleus scattering experiments aim at measurements with o (tonne)-scale detectors and substantially reduced systematic and statistical uncertainties. with such high quality data, the extraction of point-neutron distributions mean-square radii requires a better understanding of possible theoretical uncertainties. we quantify the impact of single-nucleon electromagnetic mean-square radii on the weak-charge form factor and compare results from weak-charge form factor parametrizations and weak-charge form factor decompositions in terms of elastic vector proton and neutron form factors, including nucleon form factors q-dependent terms up to order q2. we assess as well the differences arising from results derived using weak-charge form factor decompositions in terms of elastic vector proton and neutron form factors and a model-independent approach based solely on the assumption of spherically symmetric nuclear ground state. we demonstrate the impact of the main effects by assuming pseudo-data from a one-tonne lar detector and find that, among the effects and under the assumptions considered in this paper, weak-charge form factor parametrizations and weak-charge form factor decompositions in terms of elastic vector proton and neutron form factors enable the extraction of the 40ar point-neutron distribution mean-square radius with a ∼ 15% accuracy. with a substantial reduction of the beam-related neutron and steady-state backgrounds a ∼ 1% precision extraction seems feasible, using either of the two approaches. | extraction of neutron density distributions from high-statistics coherent elastic neutrino-nucleus scattering data |
we study the prospects of probing neutrino mass models at the newly proposed antimuon collider $\mu$tristan, involving $\mu^+e^-$ scattering at $\sqrt{s}= 346$ gev and $\mu^+\mu^+$ scattering at $\sqrt{s}= 2$ tev. we show that $\mu$tristan is uniquely sensitive to leptophilic neutral and doubly-charged scalars naturally occurring in various neutrino mass models, such as zee, zee-babu, cocktail, and type-ii seesaw models, over a wide range of mass and coupling values, well beyond the current experimental constraints. it also allows for the possibility to correlate the collider signals with neutrino mixing parameters and charged lepton flavor violating observables. | neutrino mass models at $\\mu$tristan |
motivated by the interesting features of two higgs doublet models (2hdm) we present a 2hdm extension where the stability of dark matter, neutrino masses and the absence of flavor changing interactions are explained by promoting baryon and lepton number to gauge symmetries. neutrino masses are addressed within the usual type i seesaw mechanism. a vector-like fermion acts as dark matter and it interacts with standard model particles via the kinetic and mass mixings between the neutral gauge bosons. we compute the relevant observables such as the dark matter relic density and spin-independent scattering cross section to outline the region of parameter space that obeys current and projected limits from collider and direct detection experiments via thermal and non-thermal dark matter production. | a two higgs doublet model for dark matter and neutrino masses |
the recent evidence for coherent elastic neutrino-nucleus scattering (ce ν ns ) in the ncc-1701 germanium detector using antineutrinos from the dresden-ii nuclear reactor is in good agreement with standard model expectations. however, we show that a 2 σ improvement in the fit to the data can be achieved if the quenching factor is described by a modified lindhard model. we also place constraints on the parameter space of a light vector or scalar mediator that couples to neutrinos and quarks, and on a neutrino magnetic moment. we demonstrate that the constraints are quite sensitive to the quenching factor at low recoil energies by comparing constraints for the standard lindhard model with those by marginalizing over the two parameters of the modified lindhard model. | implications of the first evidence for coherent elastic scattering of reactor neutrinos |
we obtain constraints on 4-lepton interactions in the effective field theory with dimension-6 operators. to this end, we combine the experimental input from z boson measurements in lep-1, w boson mass and decays, muon and tau decays, lepton pair production in lep-2, neutrino scattering on electrons, and parity violating electron scattering. the analysis does not rely on any assumptions about the flavor structure of the dimension-6 operators. our main results are the confidence intervals for wilson coefficients of 16 lepton-flavor conserving four-lepton operators, together with the full correlation matrix. consequences for leptophilic models beyond the standard model are discussed. | model independent constraints on four-lepton operators |
background: a major goal of nuclear theory is to understand the strong interaction in nuclei as it manifests itself in terms of two- and many-body forces among the nuclear constituents, the protons and neutrons, and the interactions of these constituents with external electroweak probes via one- and many-body currents. purpose: the objective of the present work is to calculate the quasielastic electroweak response functions in light nuclei within the realistic dynamical framework outlined above. these response functions determine the inclusive cross section as function of the lepton momentum and energy transfers. methods: their ab initio calculation is a very challenging quantum many-body problem, since it requires summation over the entire excitation spectrum of the nucleus and inclusion in the electroweak currents of one- and many-body terms. green's functions monte carlo methods allow one to circumvent both difficulties by computing the response in imaginary time (the so-called euclidean response) and hence summing implicitly over the bound and continuum states of the nucleus, and by implementing specific algorithms designed to deal with the complicated spin-isospin structure of nuclear many-body operators. results: theoretical predictions for 4he and 12c, confirmed by experiment in the electromagnetic case, show that two-body currents generate excess transverse strength from threshold to the quasielastic to the dip region and beyond. conclusions: these results challenge the conventional picture of quasielastic inclusive scattering as being largely dominated by single-nucleon knockout processes. | electromagnetic and neutral-weak response functions of 4he and 12c |
a search is performed for a heavy majorana neutrino (n), produced in leptonic decay of a w boson propagator and decaying into a w boson and a lepton, with the cms detector at the lhc. the signature used in this search consists of two same-sign leptons, in any flavor combination of electrons and muons, and at least one jet. the data were collected during 2016 in proton-proton collisions at a center-of-mass energy of 13 tev, corresponding to an integrated luminosity of 35.9 fb-1. the results are found to be consistent with the expected standard model background. upper limits are set in the mass range between 20 and 1600 gev in the context of a type-i seesaw mechanism, on | v en|2, | vμn|2, and | v en vμn* |2/(| v en|2 + | vμn|2), where v ℓn is the matrix element describing the mixing of n with the standard model neutrino of flavor ℓ = e , μ. for n masses between 20 and 1600 gev, the upper limits on | v ℓn|2 range between 2 .3 × 10-5 and unity. these are the most restrictive direct limits for heavy majorana neutrino masses above 430 gev. | search for heavy majorana neutrinos in same-sign dilepton channels in proton-proton collisions at √{s}=13 tev |
we present the first measurement of the single-differential νe+ν¯e charged-current inclusive cross sections on argon in electron or positron energy and in electron or positron scattering angle over the full range. data were collected using the microboone liquid argon time projection chamber located off axis from the fermilab neutrinos at the main injector beam over an exposure of 2.0 ×1020 protons on target. the signal definition includes a 60 mev threshold on the νe or ν¯e energy and a 120 mev threshold on the electron or positron energy. the measured total and differential cross sections are found to be in agreement with the genie, nuwro, and gibuu neutrino generators. | first measurement of inclusive electron-neutrino and antineutrino charged current differential cross sections in charged lepton energy on argon in microboone |
we discuss the prospects of probing the lμ-lτ gauge boson at the muone experiment. the lμ-lτ gauge boson z' with a mass of ≲200 mev , which can explain the discrepancy between the measured value of the muon g -2 and the value calculated in the standard model, can be produced at the muone experiment through the process μ e →μ e z'. the z' in the final state decays into a pair of neutrinos, and therefore we cannot observe the decay of z' directly. it is, however, still possible to probe this signature by searching for events with a large scattering angle of muon and a less energetic final-state electron. the background events coming from the elastic scattering μ e →μ e as well as radiative process μ e →μ e γ can be removed by the kinematical cuts on the muon scattering angle and the electron energy, in addition to a photon veto. the background events from the electroweak process μ e →μ e ν ν ¯ are negligible. with our selection criteria, the number of signal events μ e →μ e z' is found to be as large as ∼103, assuming an integrated luminosity of 15 fb-1, in the parameter region motivated by the muon g -2 discrepancy. it is, therefore, quite feasible to probe the lμ-lτ gauge boson at the muone experiment—without introducing additional devices—and we strongly recommend recording the events relevant to this z' production process. | probing the lμ-lτ gauge boson at the muone experiment |
the potential for probing extra neutral gauge boson mediators (z') from low-energy measurements is comprehensively explored. our study mainly focuses on z' mediators present in string-inspired e6 models and left-right symmetry. we estimate the sensitivities of coherent-elastic neutrino-nucleus scattering (ce ν ns ) and neutrino-electron scattering experiments. our results indicate that such low-energy high-intensity measurements can provide a valuable probe, complementary to high-energy collider searches and electroweak precision measurements. | probing new neutral gauge bosons with ce ν ns and neutrino-electron scattering |
high-intensity neutrino beam facilities may produce a beam of light dark matter when protons strike the target. searches for such a dark matter beam using its scattering in a nearby detector must overcome the large neutrino background. we characterize the spatial and energy distributions of the dark matter and neutrino beams, focusing on their differences to enhance the sensitivity to dark matter. we find that a dark matter beam produced by a z ' boson in the gev mass range is both broader and more energetic than the neutrino beam. the reach for dark matter is maximized for a detector sensitive to hard neutral-current scatterings, placed at a sizable angle off the neutrino beam axis. in the case of the long-baseline neutrino facility (lbnf), a detector placed at roughly 6 degrees off axis and at a distance of about 200 m from the target would be sensitive to z ' couplings as low as 0.05. this search can proceed symbiotically with neutrino measurements. we also show that the miniboone and microboone detectors, which are on fermilab's booster beamline, happen to be at an optimal angle from the numi beam and could perform searches with existing data. this illustrates potential synergies between lbnf and the short-baseline neutrino program if the detectors are positioned appropriately. | dark matter beams at lbnf |
the muone experiment aims at a precision measurement of the hadronic vacuum polarization contribution to the muon g - 2, via elastic muon-electron scattering. since the current muon g - 2 anomaly hints at the potential existence of new physics (np) related to the muon, the question then arises as to whether the measurement of hadronic vacuum polarization in muone could be affected by the same np as well. in this work, we address this question by investigating a variety of np explanations of the muon g - 2 anomaly via either vector or scalar mediators with either flavor-universal, non-universal or even flavor-violating couplings to electrons and muons. we derive the corresponding muone sensitivity in each case and find that the measurement of hadronic vacuum polarization at the muone is not vulnerable to any of these np scenarios. | muone sensitivity to new physics explanations of the muon anomalous magnetic moment |
we investigate the binding energy parameters that should be used in modeling electron and neutrino scattering from nucleons bound in a nucleus within the framework of the impulse approximation. we discuss the relation between binding energy, missing energy, removal energy (ɛ ), spectral functions and shell model energy levels and extract updated removal energy parameters from ee^' }p spectral function data. we address the difference in parameters for scattering from bound protons and neutrons. we also use inclusive e-a data to extract an empirical parameter u_{fsi}( (\varvec{q}_3+\varvec{k})^2) to account for the interaction of final state nucleons (fsi) with the optical potential of the nucleus. similarly we use v_{eff} to account for the coulomb potential of the nucleus. with three parameters ɛ , u_{fsi}( (\varvec{q}_3+\varvec{k})^2) and v_{eff} we can describe the energy of final state electrons for all available electron qe scattering data. the use of the updated parameters in neutrino monte carlo generators reduces the systematic uncertainty in the combined removal energy (with fsi corrections) from ± 20 to ± 5 mev. | removal energies and final state interaction in lepton nucleus scattering |
neutron and proton spectral functions of 40ar, 40ca, and 48ti isotopes are computed using the ab initio self-consistent green's function approach. the resulting radii and charge distributions are in good agreement with available experimental data. the spectral functions of ar and ti are then utilized to calculate inclusive (e ,e' ) cross sections within a factorization scheme and are found to correctly reproduce the recent jefferson lab measurements. based on these successful agreements, the weak charged and neutral current double-differential cross sections for neutrino-40ar scattering are predicted in the quasielastic region. results obtained by replacing the (experimentally inaccessible) neutron spectral distribution of 40ar with the (experimentally accessible) proton distribution of 48ti are compared and the accuracy of this approximation is assessed. | lepton scattering from 40ar and 48ti in the quasielastic peak region |
we present an improved determination of the strange sea distribution in the nucleon with constraints coming from the recent charm production data in neutrino-nucleon deep-inelastic scattering by the nomad and chorus experiments and from charged current inclusive deep-inelastic scattering at hera. we demonstrate that the results are consistent with the data from the atlas and the cms experiments on the associated production of w± -bosons with c -quarks. we also discuss issues related to the recent strange sea determination by the atlas experiment using lhc collider data. | determination of strange sea quark distributions from fixed-target and collider data |
background: nuclear short-range correlations (srcs) are corrections to mean-field wave functions connected with the short-distance behavior of the nucleon-nucleon interaction. these srcs provide corrections to lepton-nucleus cross sections as computed in the impulse approximation (ia). purpose: we want to investigate the influence of srcs on the one-nucleon (1 n ) and two-nucleon (2 n ) knockout channels for muon-neutrino induced processes on a 12 target at energies relevant for contemporary measurements. method: the model adopted in this work corrects the impulse approximation for srcs by shifting the complexity induced by the srcs from the wave functions to the operators. due to the local character of the srcs, it is argued that the expansion of these operators can be truncated at a low order. results: the model is compared with electron-scattering data, and two-particle two-hole responses are presented for neutrino scattering. the contributions from the vector and axial-vector parts of the nuclear current as well as the central, tensor, and spin-isospin parts of the srcs are studied. conclusions: nuclear srcs affect the 1 n knockout channel and give rise to 2 n knockout. the exclusive neutrino-induced 2 n knockout cross section of src pairs is shown and the 2 n knockout contribution to the qe signal is calculated. the strength occurs as a broad background which extends into the dip region. | influence of short-range correlations in neutrino-nucleus scattering |
a search is performed for third-generation scalar leptoquarks and heavy right-handed neutrinos in events containing one electron or muon, one hadronically decaying τ lepton, and at least two jets, using a √{s}=13 tev pp collision data sample corresponding to an integrated luminosity of 12 .9 fb-1 collected with the cms detector at the lhc in 2016. the number of observed events is found to be in agreement with the standard model prediction. a limit is set at 95% confidence level on the product of the leptoquark pair production cross section and β 2, where β is the branching fraction of leptoquark decay to a τ lepton and a bottom quark. assuming β = 1, third-generation leptoquarks with masses below 850 gev are excluded at 95% confidence level. an additional search based on the same event topology involves heavy right-handed neutrinos, nr, and right-handed w bosons, wr, arising in a left-right symmetric extension of the standard model. in this search, wr bosons are assumed to decay to a tau lepton and nr followed by the decay of the nr to a tau lepton and an off-shell wr boson. assuming the mass of the right-handed neutrino to be half of the mass of the right-handed w boson, wr boson masses below 2 .9 tev are excluded at 95% confidence level. these results improve on the limits from previous searches for third-generation leptoquarks and heavy right-handed neutrinos with τ leptons in the final state. [figure not available: see fulltext.] | search for third-generation scalar leptoquarks and heavy right-handed neutrinos in final states with two tau leptons and two jets in proton-proton collisions at √{s}=13 tev |
we present a complete comparison of semi-inclusive νμ-12c cross section measurements by t2k and miner ν a collaborations with the predictions from the susav2-mec model implemented in the neutrino-nucleus event generator genie and an unfactorized approach based on the relativistic distorted wave impulse approximation. results, that include cross sections as function of the final muon and proton kinematics and correlations between both, show that the agreement with data obtained by the relativistic distorted wave impulse approximation approach, that accounts for final-state interactions, matches or improves genie-susav2 predictions for very forward angles where scaling violations are relevant. | final state interactions in semi-inclusive neutrino-nucleus scattering: applications to the t2k and miner ν a experiments |
in a truly model-independent approach, we reexamine a minimal extension of the standard model (sm) through the introduction of an additional u (1 ) symmetry leading to a new neutral gauge boson (z' ), allowing its kinetic mixing with the hypercharge gauge boson. an sm neutral scalar is used to spontaneously break this extra symmetry, leading to the mass of the z'. except for three right-handed neutrinos, no other fermions are added. we use the current lhc drell-yan data to put model-independent constraints in the parameter space of three quantities, namely, mz', the z -z' mixing angle (αz), and the extra u (1 ) effective gauge coupling (gx'), which absorb all model dependence. we impose additional constraints from unitarity and low-energy neutrino-electron scattering. however, limits extracted from direct searches turn out to be most stringent. we obtain mz'>4.4 tev and |αz|<0.001 at 95% c.l., when the strength of the additional u (1 ) gauge coupling is the same as that of the sm s u (2 )l. | reappraisal of constraints on z' models from unitarity and direct searches at the lhc |
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 production 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 $x\approx10^{-6}$. 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 |
neutrino-nucleus scattering ν a →ν a , in which the nucleus conserves its integrity, is considered. our consideration follows a microscopic description of the nucleus as a bound state of its constituent nucleons described by a multiparticle wave function of a general form. we show that elastic interactions keeping the nucleus in the same quantum state lead to a quadratic enhancement of the corresponding cross section in terms of the number of nucleons. meanwhile, the cross section of inelastic processes in which the quantum state of the nucleus is changed, essentially has a linear dependence on the number of nucleons. these two classes of processes are referred to as coherent and incoherent, respectively. accounting for all possible initial and final internal states of the nucleus leads to a general conclusion independent of the nuclear model. the coherent and incoherent cross sections are driven by factors |fp /n|2 and (1 -|fp /n|2) , where |fp /n|2 is a proton/neutron form factor of the nucleus, averaged over its initial states. therefore, our assessment suggests a smooth transition between regimes of coherent and incoherent neutrino-nucleus scattering. in general, both regimes contribute to experimental observables. the coherent cross-section formula used in the literature is revised and corrections depending on kinematics are estimated. consideration of only those matrix elements which correspond to the same initial and final spin states of the nucleus and accounting for a nonzero momentum of the target nucleon are two main sources of the corrections. as an illustration of the importance of the incoherent channel, we considered three experimental setups with different nuclei. as an example, for 133cs and neutrino energies of 30-50 mev, the incoherent cross section is about 10%-20% of the coherent contribution if the experimental detection threshold is accounted for. experiments attempting to measure coherent neutrino scattering by solely detecting the recoiling nucleus, as is typical, might be including an incoherent background that is indistinguishable from the signal if the excitation gamma eludes its detection. however, as is shown here, the incoherent component can be measured directly by searching for photons released by the excited nuclei inherent to the incoherent channel. for a beam experiment these gammas should be correlated in time with the beam, and their higher energies make the corresponding signal easily detectable at a rate governed by the ratio of incoherent to coherent cross sections. the detection of signals due to the nuclear recoil and excitation γ s provides a more sensitive instrument in studies of nuclear structure and possible signs of new physics. | coherency and incoherency in neutrino-nucleus elastic and inelastic scattering |
new measurements of the coherent elastic neutrino-nucleus scattering (cevns) are expected to be achieved in the near future by using two neutrino production channels with different energy distributions: the very low energy electron antineutrinos from reactor sources and the muon and electron neutrinos from spallation neutron sources (sns) with a relatively higher energy. although precise measurements of this reaction would allow for an improved knowledge of standard and beyond the standard model physics, it is important to distinguish the different new contributions to the process. we illustrate this idea by constraining the average neutron root mean square (rms) radius of the scattering material, as a standard physics parameter, together with the nonstandard interactions (nsi) contribution as the new physics formalism. we show that the combination of experiments with different neutrino energy ranges could give place to more robust constraints on these parameters as long as the systematic errors are under control. | interplay between nonstandard and nuclear constraints in coherent elastic neutrino-nucleus scattering experiments |
we study the impact of non-standard neutrino interactions in the context of a new gauge boson z' in neutral-current deep-inelastic scattering performed in forward search experiment-ν (faserν) and in monojet production at the large hadron collider (lhc). we simulate the neutral-current deep-inelastic neutrino-nucleon scattering νn → νn at faserν in the presence of an additional z' boson, and estimate the anticipated sensitivities to the gauge coupling in a wide range of z' mass. at the lhc, we study the effect of z' on monojet production, which can be enhanced in regions with large missing transverse momenta. we then use the recent results from atlas with an integrated luminosity of 139 fb−1 to improve the limits on the gauge coupling of z'. we interpret such limits on z' gauge couplings as bounds on effective non-standard neutrino interactions. we show that the faserν and the lhc results cover the medium and high energy scales, respectively, and complement one another. | non-standard neutrino and z' interactions at the faserν and the lhc |
a search for new particles has been conducted using events with two high transverse momentum τ leptons that decay hadronically and at least two energetic jets. the analysis is performed using data from proton-proton collisions at √{s}=13 tev, collected by the cms experiment at the lhc in 2016 and corresponding to an integrated luminosity of 35.9 fb-1. the observed data are consistent with standard model expectations. the results are interpreted in the context of two physics models. the first model involves right-handed charged bosons, wr, that decay to heavy right-handed majorana neutrinos, n ℓ( ℓ = e, μ, τ), arising in a left-right symmetric extension of the standard model. the model considers that ne and n μare too heavy to be detected at the lhc. assuming that the n τmass is half of the wr mass, masses of the wr boson below 3.50 tev are excluded at 95% confidence level. exclusion limits are also presented considering different scenarios for the mass ratio between n τand wr, as a function of wr mass. in the second model, pair production of third-generation scalar leptoquarks that decay into ττbb is considered, resulting in an observed exclusion region with leptoquark masses below 1.02 tev, assuming a 100% branching fraction for the leptoquark decay to a τ lepton and a bottom quark. these results represent the most stringent limits to date on these models. | search for heavy neutrinos and third-generation leptoquarks in hadronic states of two τ leptons and two jets in proton-proton collisions at √{s}=13 tev |
we discuss various aspects of a neutrino physics program that can be carried out with the neutrino beam-dump experiment drift (ν bdx -drift ) detector using neutrino beams produced in next generation neutrino facilities. ν bdx -drift is a directional low-pressure time projection chamber detector suitable for measurements of coherent elastic neutrino-nucleus scattering (ce ν ns ) using a variety of gaseous target materials which include carbon disulfide, carbon tetrafluoride and tetraethyllead, among others. the neutrino physics program includes standard model measurements and beyond the standard model physics searches. focusing on the long baseline neutrino facility beam line at fermilab, we first discuss basic features of the detector and estimate backgrounds, including beam-induced neutron backgrounds. we then quantify the ce ν ns signal in the different target materials and study the sensitivity of ν bdx -drift to measurements of the weak mixing angle and neutron density distributions. we consider as well prospects for new physics searches, in particular sensitivities to effective neutrino nonstandard interactions. | coherent elastic neutrino-nucleus scattering with the ν bdx -drift directional detector at next generation neutrino facilities |
the connie detector prototype is operating at a distance of 30 m from the core of a 3.8 gwth nuclear reactor with the goal of establishing charge-coupled devices (ccd) as a new technology for the detection of coherent elastic neutrino-nucleus scattering. we report on the results of the engineering run with an active mass of 4 g of silicon. the ccd array is described, and the performance observed during the first year is discussed. a compact passive shield was deployed around the detector, producing an order of magnitude reduction in the background rate. the remaining background observed during the run was stable, and dominated by internal contamination in the detector packaging materials. the in-situ calibration of the detector using x-ray lines from fluorescence demonstrates good stability of the readout system. the event rates with the reactor on and off are compared, and no excess is observed coming from nuclear fission at the power plant. the upper limit for the neutrino event rate is set two orders of magnitude above the expectations for the standard model. the results demonstrate the cryogenic ccd-based detector can be remotely operated at the reactor site with stable noise below 2 e- rms and stable background rates. the success of the engineering test provides a clear path for the upgraded 100 g detector to be deployed during 2016. | results of the engineering run of the coherent neutrino nucleus interaction experiment (connie) |
majorana neutrino electromagnetic properties are studied through neutral current coherent neutrino-nucleus scattering. we focus on the potential of the recently planned coherent experiment at the spallation neutron source to probe muon-neutrino magnetic moments. the resulting sensitivities are determined on the basis of a χ2 analysis employing realistic nuclear structure calculations in the context of the quasiparticle random phase approximation. we find that they can improve existing limits by half an order of magnitude. in addition, we show that these facilities allow for standard model precision tests in the low energy regime, with a competitive determination of the weak mixing angle. finally, they also offer the capability to probe other electromagnetic neutrino properties, such as the neutrino charge radius. we illustrate our results for various choices of experimental setup and target material. | probing neutrino magnetic moments at the spallation neutron source facility |
we report the first measurement of the flux-integrated cross section of νμ charged-current single π0 production on argon. this measurement is performed with the microboone detector, an 85 ton active mass liquid argon time projection chamber exposed to the booster neutrino beam at fermilab. this result on argon is compared to past measurements on lighter nuclei to investigate the scaling assumptions used in models of the production and transport of pions in neutrino-nucleus scattering. the techniques used are an important demonstration of the successful reconstruction and analysis of neutrino interactions producing electromagnetic final states using a liquid argon time projection chamber operating at the earth's surface. | first measurement of νμ charged-current π0 production on argon with the microboone detector |
neutrino elastic scattering observation with nai (neon) is an experiment designed to detect neutrino-nucleus coherent scattering using reactor electron antineutrinos. neon is based on an array of six nai(tl) crystals with a total mass of 13.3 kg, located at the tendon gallery that is 23.7 m away from a reactor core with a thermal power of 2.8 gw in the hanbit nuclear power complex. the installation of the neon detector was completed in december 2020, and since may 2021, the detector has acquired data at full reactor power. based on the observed light yields of the nai crystals of approximately 22, number of photoelectrons per unit kev electron-equivalent energy (kevee), and 6 counts/kg/kev/day background level at 2-6 kevee energy, coherent elastic neutrino-nucleus scattering (ceν ns) observation sensitivity is evaluated as more than 3σ assuming 1-year reactor-on and 100 days reactor-off data, 0.2 kevee energy threshold, and 7 counts/kev/kg/day background in the signal region of 0.2-0.5 kevee. this paper describes the design of the neon detector, including the shielding arrangement, configuration of nai(tl) crystals, and associated operating systems. the initial performance and associated sensitivity of the experiment are also presented. | exploring coherent elastic neutrino-nucleus scattering using reactor electron antineutrinos in the neon experiment |
we study neutrino-nucleus charged-current reactions on finite nuclei for the situation in which an outgoing muon and a proton are detected in coincidence; i.e., we focus on semi-inclusive cross sections. we limit our attention to one-body current interactions (quasielastic scattering) and assess the impact of different nuclear effects in the determination of the neutrino energy. we identify the regions in phase space where the neutrino energy can be reconstructed relatively well and study whether the cross section in those regions is significant. our results indicate that it is possible to filter more than 50% of all events according to the muon and proton kinematics, so that for the dune and t2k fluxes the neutrino energy can be determined with uncertainties of less than 1% and 3%, respectively. furthermore, we find that the reconstructed neutrino energy does not depend strongly on how one treats the final-state interactions and is not much affected by the description of the initial state. on the other hand, the estimations of the uncertainty on the neutrino energy show important sensitivity to the modeling of the initial state. | neutrino energy reconstruction from semi-inclusive samples |
we present a novel lepton-nucleus event generator: achilles, a chicago land lepton event simulator. the generator factorizes the primary interaction from the propagation of hadrons in the nucleus, which allows for a great deal of modularity, facilitating further improvements and interfaces with existing codes. we validate our generator against high-quality electron-carbon scattering data in the quasielastic regime, including the recent clas/e4v reanalysis of existing data. we find promising agreement in both inclusive and exclusive distributions. by varying the assumptions on the propagation of knocked-out nucleons throughout the nucleus, we estimate a component of theoretical uncertainties. we also propose novel observables that will allow for further testing of lepton-nucleus scattering models. achilles is readily extendable to generate neutrino-nucleus scattering events. | introducing a novel event generator for electron-nucleus and neutrino-nucleus scattering |
we present the constraints on the parameters of several light boson mediator models obtained from the analysis of the current data of the coherent ceνns experiment. we consider a variety of vector boson mediator models: the so-called universal, the b − l and other anomaly-free u(1)' gauge models with direct couplings of the new vector boson with neutrinos and quarks, and the anomaly-free le− lμ, le− lτ, and lμ− lτ gauge models where the coupling of the new vector boson with the quarks is generated by kinetic mixing with the photon at the one-loop level. we consider also a model with a new light scalar boson mediator that is assumed, for simplicity, to have universal coupling with quarks and leptons. since the coherent ceνns data are well-fitted with the cross section predicted by the standard model, the analysis of the data yields constraints for the mass and coupling of the new boson mediator that depend on the charges of quarks and neutrinos in each model under consideration. we compare these constraints with the limits obtained in other experiments and with the values that can explain the muon g − 2 anomaly in the models where the muon couples to the new boson mediator. | probing light mediators and (g − 2)μ through detection of coherent elastic neutrino nucleus scattering at coherent |
an event generation framework is presented that enables the automatic simulation of events for next-generation neutrino experiments in the standard model or extensions thereof. the new generator combines the calculation of the leptonic current based on an automated matrix element generator and the computation of the hadronic current based on a state-of-the-art nuclear physics model. the approach is validated in standard model simulations for electron scattering and neutrino scattering. furthermore, the first fully differential neutrino trident production results are shown in the quasielastic region. | novel event generator for the automated simulation of neutrino scattering |
we consider a hidden u (1) gauge symmetry under which only the right-handed neutrinos (νr) are charged. the corresponding gauge boson is referred to as the νr-philic z'. despite the absence of direct gauge couplings to ordinary matter at tree level, loop-induced couplings of the νr-philic z' via left-right neutrino mixing can be responsible for its experimental accessibility. an important feature of the νr-philic z' is that its couplings to neutrinos are generally much larger than its couplings to charged leptons and quarks, thus providing a particularly interesting scenario for future neutrino experiments such as dune to probe. we consider two approaches to probe the νr-philic z' at dune near detectors via (i) searching for z' decay signals, and (ii) precision measurement of elastic neutrino-electron scattering mediated by the z' boson. we show that the former will have sensitivity comparable to or better than previous beam dump experiments, while the latter will improve current limits substantially for large neutrino couplings. | probing the νr-philic z' at dune near detectors |
we examine the potential to probe generalized neutrino interactions (gnis), exotic effective couplings due to new physics interactions beyond the standard model, in the coherent-elastic neutrino-nucleus scattering experiments in light of the latest coherent-csi and -lar data. our analysis focuses on scalar-, vector-, and tensor-flavored gni parameters. a combined analysis has been made to constrain these exotic couplings for the csi and lar detector. we further add the projected forthcoming reactor-based scintillating bubble chamber detector to examine these couplings. it has been observed that the addition of reactor data strongly constrained electron flavor gnis. | ce ν ns as a probe of flavored generalized neutrino interactions |
the electron (anti-)neutrino component of the t2k neutrino beam constitutes the largest background in the measurement of electron (anti-)neutrino appearance at the far detector. the electron neutrino scattering is measured directly with the t2k off-axis near detector, nd280. the selection of the electron (anti-)neutrino events in the plastic scintillator target from both neutrino and anti-neutrino mode beams is discussed in this paper. the flux integrated single differential charged-current inclusive electron (anti-)neutrino cross-sections, dσ/dp and dσ/d cos(θ), and the total cross-sections in a limited phase-space in momentum and scattering angle (p > 300 mev/c and θ ≤ 45°) are measured using a binned maximum likelihood fit and compared to the neutrino monte carlo generator predictions, resulting in good agreement. | measurement of the charged-current electron (anti-)neutrino inclusive cross-sections at the t2k off-axis near detector nd280 |
motivated by the low-energy electron recoil spectrum observed by the dark matter experiment, xenon1t, at gran sasso laboratory, we interpret the observed signal not in terms of a dark matter particle, but rather in the context of a new light z‧ gauge boson. we discuss how such a light z‧ emerges in a two higgs doublet model augmented by an abelian gauge symmetry where neutrino masses and the flavor problem are addressed, in agreement with neutrino-electron scattering data. | xenon1t anomaly: a light z‧ from a two higgs doublet model |
we determine the four-fermion effective theory of neutrino interactions within the standard model including one-loop electroweak radiative corrections, in combination with the measured muon lifetime and precision electroweak data. including two-loop matching and three-loop running corrections, we determine lepton coefficients accounting for all large logarithms through relative order o (ααs) and quark coefficients accounting for all large logarithms through o (α). we present four-fermion coefficients valid in nf = 3 and nf = 4 flavor quark theories, as well as in the extreme low-energy limit. we relate the coefficients in this limit to neutrino charge radii governing matter effects via forward neutrino scattering on charged particles. | on the effective theory of neutrino-electron and neutrino-quark interactions |
the development of low-threshold detectors for the study of coherent elastic neutrino-nucleus scattering and for the search for light dark matter necessitates methods of low-energy calibration. we suggest this can be provided by the nuclear recoils resulting from the γ emission following thermal neutron capture. in particular, several mev-scale single-γ transitions induce well-defined nuclear recoil peaks in the 100 ev range. using the fifrelin code, complete schemes of γ-cascades for various isotopes can be predicted with high accuracy to determine the continuous background of nuclear recoils below the calibration peaks. we present a comprehensive experimental concept for the calibration of cawo4 and ge cryogenic detectors at a research reactor. for cawo4 the simulations show that two nuclear recoil peaks at 112.5 ev and 160.3 ev should be visible above background simply in the spectrum of the cryogenic detector. then we discuss how the additional tagging for the associated γ increases the sensitivity of the method and extends its application to a wider energy range and to ge cryogenic detectors. | calibration of nuclear recoils at the 100 ev scale using neutron capture |
we explore the potential of jet observables in charged-current deep inelastic scattering events at the future electron-ion collider. tagging jets with a recoiling neutrino, which can be identified by the event's missing transverse momentum, will allow for flavor-sensitive measurements of transverse momentum dependent parton distribution functions. we present the first predictions for transverse-spin asymmetries in azimuthal neutrino-jet correlations and hadron-in-jet measurements. we study the kinematic reach and the precision of these measurements and explore their feasibility using parametrized detector simulations. we conclude that jet production in charged-current deep inelastic scattering, while challenging in terms of luminosity requirements, will complement the electron-ion collider experimental program to study the three-dimensional structure of the nucleon encoded in transverse momentum dependent parton distribution functions. | neutrino-tagged jets at the electron-ion collider |
the spallation neutron source (sns) at oak ridge national laboratory is a pulsed source of neutrons and, as a by-product of this operation, an intense source of pulsed neutrinos via stopped-pion decay. the coherent collaboration uses this source to investigate coherent elastic neutrino-nucleus scattering and other physics with a suite of detectors. this work includes a description of our geant4 simulation of neutrino production at the sns and the flux calculation which informs the coherent studies. we estimate the uncertainty of this calculation at the ∼10 % level based on validation against available low-energy π+ production data. | simulating the neutrino flux from the spallation neutron source for the coherent experiment |
neutrino-nucleus cross section uncertainties are expected to be a dominant systematic in future accelerator neutrino experiments. the cross sections are determined by the linear response of the nucleus to the weak interactions of the neutrino, and are dominated by energy and distance scales of the order of the separation between nucleons in the nucleus. these response functions are potentially an important early physics application of quantum computers. here we present an analysis of the resources required and their expected scaling for scattering cross section calculations. the current estimates of trotter steps needed to achieve an energy resolution of 10 mev and the number of cnot gates for analyzing 40ar highlights the need for significant improvements in algorithms. we also examine simple small-scale neutrino-nucleus models on modern quantum hardware. in this paper, we use variational methods to obtain the ground state of a three nucleon system (the triton) and then implement the relevant time evolution. to tame the errors in present-day nisq devices, we explore the use of different error-mitigation techniques to increase the fidelity of the calculations. | quantum computing for neutrino-nucleus scattering |
we analyze new data from the coherent experiment of the coherent neutrino-nucleus scattering to investigate the electromagnetic interactions of neutrinos. with almost double the statistics and precision now, the statistical significance of the observed process has now enhanced to 11.6σ. we derive constraints on the electromagnetic properties of neutrinos using the new coherent data. the constraints improve by more than a factor of two compared to the previous bounds. furthermore, we discuss the unique behavior of the neutrino millicharge at lower energy recoils and show its unique dependence on its interference with the standard model contribution, inverse power of recoil energy and the mass of the target particle in comparison to the other interactions. | neutrino millicharge and other electromagnetic interactions with coherent-2021 data |
the atomki collaboration has reported that unexpected excesses have been observed in the rare decays of beryllium nucleus. it is claimed that such excesses can suggest the existence of a new boson, called x, with the mass of about 17 mev. to solve the atomki anomaly, we consider a model with gauged u(1)r symmetry and identify the new gauge boson with the x boson. we also introduce two su(2) doublet higgs bosons and one singlet higgs boson, and discuss a very stringent constraint from neutrino-electron scattering. it is found that the u(1)r charges of the doublet scalars are determined to evade the constraint. in the end, we find the parameter region in which the atomki signal and all experimental constraints can be simultaneously satisfied. | atomki anomaly in gauged u(1)r symmetric model |
the proposed mitchell institute neutrino experiment at reactor (miner) experiment at the nuclear science center at texas a&m university will search for coherent elastic neutrino-nucleus scattering within close proximity (about 2 meters) of a 1 mw triga nuclear reactor core using low threshold, cryogenic germanium and silicon detectors. given the standard model cross section of the scattering process and the proposed experimental proximity to the reactor, as many as 5 to 20 events/kg/day are expected. we discuss the status of preliminary measurements to characterize the main backgrounds for the proposed experiment. both in situ measurements at the experimental site and simulations using the mcnp and geant4 codes are described. a strategy for monitoring backgrounds during data taking is briefly discussed. | background studies for the miner coherent neutrino scattering reactor experiment |
we revisit the possibility of distinguishing between dirac and majorana neutrinos via neutrino-electron elastic scattering in the presence of all possible lorentz-invariant interactions. defining proper observables, certain regions of the parameter space can only be reached for dirac neutrinos, but never for majorana neutrinos, thus providing an al-ternative method to differentiate these two possibilities. we first derive analytically and numerically the most general conditions that would allow to distinguish dirac from ma-jorana neutrinos, both in the relativistic and non-relativistic cases. then, we apply these conditions to data on νμ - e and {\overline{ν}}_e-e scatterings, from the charm-ii and texono experi-ments, and find that they are consistent with both types of neutrinos. finally, we comment on future prospects of this kind of tests. | distinguishing between dirac and majorana neutrinos in the presence of general interactions |
this paper presents a measurement of zz production with the atlas detector at the large hadron collider. the measurement is carried out in the final state with two charged leptons and two neutrinos, using data collected during 2015 and 2016 in pp collisions at √{s } = 13 tev, corresponding to an integrated luminosity of 36.1 fb-1. the integrated cross-sections in the total and fiducial phase spaces are measured with an uncertainty of 7% and compared with standard model predictions, and differential measurements in the fiducial phase space are reported. no significant deviations from the standard model predictions are observed, and stringent constraints are placed on anomalous couplings corresponding to neutral triple gauge-boson interactions. | measurement of zz production in the ℓℓνν final state with the atlas detector in pp collisions at √{s } = 13 tev |
to probe cp violation in the leptonic sector using gev energy neutrino beams in current and future experiments using argon detectors, precise models of the complex underlying neutrino and antineutrino interactions are needed. the e12-14-012 experiment at jefferson lab hall a was designed to perform a combined analysis of inclusive and exclusive electron scatterings on both argon (n =22 ) and titanium (z =22 ) nuclei using gev-energy electron beams. the measurement on titanium nucleus provides essential information to understand the neutrino scattering on argon, large contribution to which comes from scattering off neutrons. here we report the first experimental study of electron-titanium scattering as double-differential cross section at beam energy e =2.222 gev and electron-scattering angle θ =15 .541∘ , measured over a broad range of energy transfer, spanning the kinematical regions in which quasielastic scattering and delta production are the dominant reaction mechanisms. the data provide valuable new information needed to develop accurate theoretical models of the electromagnetic and weak cross sections of these complex nuclei in the kinematic regime of interest to neutrino experiments. | first measurement of the ti (e ,e')x cross section at jefferson lab |
motivated by the first observation of coherent-elastic neutrino-nucleus scattering at the coherent experiment, we confront the neutrino dipole portal giving rise to the transition of the standard model neutrinos to sterile neutrinos with the recently released cenns 10 data from the liquid argon as well as the csi data of the coherent experiment. performing a statistical analysis of those data, we show how the transition magnetic moment can be constrained for the range of the sterile neutrino mass between 10 kev and 40 mev. | probing neutrino dipole portal at coherent experiment |
we study neutral- and charged-current (anti)neutrino-induced dissociation of the deuteron at energies from threshold up to 150 mev by employing potentials, as well as one- and two-body currents, derived in chiral effective field theory (χ eft ). we provide uncertainty estimates from χ eft truncations of the electroweak current, dependences on the χ eft cutoff, and variations in the pool of fit data used to fix the low-energy constants of χ eft . at 100 mev of incident (anti)neutrino energy, these uncertainties amount to about 2-3% and are smaller than the sensitivity of the cross sections to the single-nucleon axial form factor, which amounts to 5 % if one varies the range of the nucleon axial radius within the bands determined by recent lattice quantum chromodynamics evaluations and phenomenological extractions. we conclude that a precise determination of the nucleon axial form factor is required for a high-precision calculation of the neutrino-deuteron cross sections at energies higher than 100 mev. by matching our low-energy χ eft results to those of pionless effective field theory (π eft ), we provide new constraints for the counterterm l1 ,a that parametrizes the strength of the axial two-body current in π eft. we obtain a value of 4 .9-1.5+1.9fm3 at renormalization scale set to pion mass, which is compatible with, albeit narrower than, previous experimental determinations, and comparable to a recent lattice quantum chromodynamics calculation. | neutrino-deuteron scattering: uncertainty quantification and new l1 ,a constraints |
a set of comparisons among neutrino interaction experiments [miniboone, minerva, tokai-to-kamioka (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. efficiencies 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 |
the coherent collaboration observed coherent elastic neutrino nucleus scattering using a 14.6 kg cesium-iodide (csi) detector in 2017 and recently published the updated results before decommissioning the detector. here, we present the legacy determination of the weak mixing angle and of the average neutron rms radius of 133cs and 127i obtained with the full csi dataset, also exploiting the combination with the atomic parity violation (apv) experimental result, that allows us to achieve a precision as low as ∼ 4.5% and to disentangle the contributions of the 133cs and 127i nuclei. interestingly, we show that the coherent csi data show a 6σ evidence of the nuclear structure suppression of the full coherence. moreover, we derive a data-driven apv+coherent measurement of the low-energy weak mixing angle with a percent uncertainty, independent of the value of the average neutron rms radius of 133cs and 127i, that is allowed to vary freely in the fit. additionally, we extensively discuss the impact of using two different determinations of the theoretical parity non-conserving amplitude in the apv fit. our findings show that the particular choice can make a significant difference, up to 6.5% on rn(cs) and 11% on the weak mixing angle. finally, in light of the recent announcement of a future deployment of a 10 kg and a ∼ 700 kg cryogenic csi detectors, we provide future prospects for these measurements, comparing them with other competitive experiments that are foreseen in the near future. | nuclear neutron radius and weak mixing angle measurements from latest coherent csi and atomic parity violation cs data |
the red-100 two-phase xenon emission detector has been deployed at 19-m distance from the reactor core of the kalinin nuclear power plant (knpp) in 2021-2022 for investigation of the possibility to observe reactor antineutrinos using the effect of coherent elastic neutrino-nucleus scattering (ceνns). the performance of the main systems of the red-100 setup at operating nuclear power plant is described. there is no correlation of the radioactive background at the experimental setup site with on and off states of the reactor. the data taking run was carried out at the beginning of the year 2022 and covered both the reactor off and on periods. | the red-100 experiment |
a search for majorana neutrinos in same-sign ww scattering events is presented. the analysis uses √{s }=13 tev proton-proton collision data with an integrated luminosity of 140 fb-1 recorded during 2015-2018 by the atlas detector at the large hadron collider. the analysis targets final states including exactly two same-sign muons and at least two hadronic jets well separated in rapidity. the modelling of the main backgrounds, from standard model same-sign ww scattering and wz production, is constrained with data in dedicated signal-depleted control regions. the distribution of the transverse momentum of the second-hardest muon is used to search for signals originating from a heavy majorana neutrino with a mass between 50 gev and 20 tev. no significant excess is observed over the background expectation. the results are interpreted in a benchmark scenario of the phenomenological type-i seesaw model. in addition, the sensitivity to the weinberg operator is investigated. upper limits at the 95% confidence level are placed on the squared muon-neutrino-heavy-neutrino mass-mixing matrix element | vμ n|2 as a function of the heavy majorana neutrino's mass mn, and on the effective μ μ majorana neutrino mass | mμ μ|. | search for majorana neutrinos in same-sign ww scattering events from pp collisions at √{s }=13 tev |
the nucleus experiment aims for the detection of coherent elastic neutrino-nucleus scattering at a nuclear power reactor with gram-scale, ultra-low-threshold cryogenic detectors. this technology leads to a miniaturization of neutrino detectors and allows to probe physics beyond the standard model of particle physics. a 0.5 g nucleus prototype detector, operated above ground in 2017, reached an energy threshold for nuclear recoils of below 20 ev. this sensitivity is achieved with tungsten transition edge sensors which are operating at temperatures of 15 mk and are mainly sensitive to non-thermal phonons. these small recoil energies become accessible for the first time with this technology, which allows collecting large-statistics neutrino event samples with a moderate detector mass. a first-phase cryogenic detector array with a total mass of 10 g enables a 5-sigma observation of coherent scattering within several weeks. we identified a suitable experimental site at the chooz nuclear power plant and performed muon and neutron background measurements there. the operation of a nucleus cryogenic detector array at such a site requires highly efficient background suppression. nucleus plans to use an innovative technique consisting of separate cryogenic anticoincidence detectors against surface backgrounds and penetrating (gamma, neutron) radiation. we present first results from prototypes of these veto detectors and their operation in coincidence with a nucleus target detector. | nucleus: exploring coherent neutrino-nucleus scattering with cryogenic detectors |
we present a fully differential next-to-next-to-leading order calculation of charm-quark production in charged-current deep-inelastic scattering, with full charm-quark mass dependence. the next-to-next-to-leading order corrections in perturbative quantum chromodynamics are found to be comparable in size to the next-to-leading order corrections in certain kinematic regions. we compare our predictions with data on dimuon production in (anti)neutrino scattering from a heavy nucleus. our results can be used to improve the extraction of the parton distribution function of a strange quark in the nucleon. | charm-quark production in deep-inelastic neutrino scattering at next-to-next-to-leading order in qcd |
faserν is a newly proposed detector whose main mission is to detect the neutrino flux from the collision of the proton beams at the atlas interaction point (ip) during the run iii of the lhc in 2022-2024. we show that this detector can also test certain beyond standard model scenarios, especially the ones in which the neutrino interaction with matter fields can produce new unstable particles decaying back into charged leptons. models of this kind are motivated by the miniboone anomaly. we show that, if the new physics involves multi-muon production by neutrinos scattering off matter fields, including the neutrino flux interactions in the rock before the detector in the analysis (i.e., accounting for the through-going muon pairs) can significantly increase the effective detector mass and its sensitivity to new physics. we propose a concrete model that can give rise to such a multi-muon signal. | discovery potential of faserν with contained vertex and through-going events |
neutrino-nucleus elastic scattering provides a unique laboratory to study the quantum mechanical coherency effects in electroweak interactions, towards which several experimental programs are being actively pursued. we report results of our quantitative studies on the transitions towards decoherency. a parameter (α ) is identified to describe the degree of coherency, and its variations with incoming neutrino energy, detector threshold, and target nucleus are studied. the ranges of α that can be probed with realistic neutrino experiments are derived, indicating complementarity between projects with different sources and targets. uncertainties in nuclear physics and in α would constrain sensitivities in probing physics beyond the standard model. the maximum neutrino energies corresponding to α >0.95 are derived. | coherency in neutrino-nucleus elastic scattering |
we report constraints on nonstandard neutrino interactions (nsi) from the observation of atmospheric neutrinos with icecube, limiting all individual coupling strengths from a single dataset. furthermore, icecube is the first experiment to constrain flavor-violating and nonuniversal couplings simultaneously. hypothetical nsi are generically expected to arise due to the exchange of a new heavy mediator particle. neutrinos propagating in matter scatter off fermions in the forward direction with negligible momentum transfer. hence the study of the matter effect on neutrinos propagating in the earth is sensitive to nsi independently of the energy scale of new physics. we present constraints on nsi obtained with an all-flavor event sample of atmospheric neutrinos based on three years of icecube deepcore data. the analysis uses neutrinos arriving from all directions, with reconstructed energies between 5.6 gev and 100 gev. we report constraints on the individual nsi coupling strengths considered singly, allowing for complex phases in the case of flavor-violating couplings. this demonstrates that icecube is sensitive to the full nsi flavor structure at a level competitive with limits from the global analysis of all other experiments. in addition, we investigate a generalized matter potential, whose overall scale and flavor structure are also constrained. | all-flavor constraints on nonstandard neutrino interactions and generalized matter potential with three years of icecube deepcore data |
we explore the sensitivity of the deep underground neutrino experiment (dune) near detector and the proposed dune-prism movable near detector to sub-gev dark matter, specifically scalar dark matter coupled to the standard model via a sub-gev dark photon. we consider dark matter produced in the dune target that travels to the detector and scatters off electrons. by combining searches for dark matter at many off-axis positions with dune-prism, sensitivity to this scenario can be much stronger than when performing a measurement at one on-axis position. | dune-prism sensitivity to light dark matter |
coherent elastic neutrino-nucleus scattering (ce ν ns ) can be used to determine the neutron part of nuclear form factors, unlocking intrinsic properties of nuclear structure. in contrast with other such methods, ce ν ns is free from both strong interaction effects and coulomb distortions. we propose precision measurements of ce ν ns with an upcoming accelerator facility and determine the corresponding requirements for such a neutrino detector. we find that most significant backgrounds come from fast neutrons, induced by cosmogenic muons or from the pion decays at rest in the target station. with ton-scale liquid noble gas detectors, we will not only achieve percent-level precision in the measurement of neutron radii but also clarify contributions of higher-order moments to nuclear form factors. | extracting nuclear form factors with coherent neutrino scattering |
we study the sensitivity of detectors with directional sensitivity to coherent elastic neutrino-nucleus scattering (ce ν ns ), and how these detectors complement measurements of the nuclear recoil energy. we consider stopped pion and reactor neutrino sources, and use gaseous helium and fluorine as examples of detector material. we generate standard model predictions, and compare to scenarios that include new, light vector or scalar mediators. we show that directional detectors can provide valuable additional information in discerning new physics, and we identify prominent spectral features in both the angular and the recoil energy spectrum for light mediators, even for nuclear recoil energy thresholds as high as ∼50 kev . combined with energy and timing information, directional information can play an important role in extracting new physics from ce ν ns experiments. | coherent elastic neutrino-nucleus scattering with directional detectors |
experiments that use liquid noble gases as target materials, such as argon and xenon, play a significant role in direct detection searches for weakly interacting massive particles(-like) dark matter. as these experiments grow in size, they will soon encounter a new background to their dark matter discovery potential from neutrino scattering off nuclei and electrons in their targets. therefore, a better understanding of this new source of background is crucial for future large-scale experiments such as argo and darwin. in this work, we study the impact of atmospheric neutrino flux uncertainties, electron recoil rejection efficiency, recoil energy sensitivity, and other related factors on the dark matter discovery reach. we also show that a significant improvement in sensitivity can potentially be obtained, at large exposures, by combining data from independent argon and xenon experiments. | neutrino backgrounds in future liquid noble element dark matter direct detection experiments |
the (g − 2)μ anomaly indicates that the second generation of leptons should have new interactions beyond the standard model. the high flux of νμ and ν ¯μ at the forward experiments such as faserν and snd@lhc makes them suitable setups to search for new interactions of the second generation leptons. in this paper, we build a model in which the second generation left-handed leptons couple to a new right-handed neutrino, n and a new higgs doublet which also couples to the quarks. the scattering of high energy νμ off nuclei can produce n. we investigate how forward experiments can test this model by looking for the n production vertex followed by the displaced vertex of the n decay. discovering even a single such event can be a harbinger to look for the spectacular signals of the new higgs doublet production at the lhc. we discuss the possibility of explaining the (g − 2)μ anomaly by adding more generations of n which will lead to chain decays of n and multiple leptons with distinct signals both at forward experiments and at the cms and atlas detectors. finally, we show that by adding a new light singlet scalar mixed with the neutral component of the new higgs doublet (i.e., 2hdm+s model), the statistics of the data sample can be dramatically increased. | neutral exotica at faserν and snd@lhc |
recent measurements of the germanium quenching factor deviate significantly from the predictions of the standard lindhard model for nuclear recoil energies below a kev. this departure may be explained by the migdal effect in neutron scattering on germanium. we show that the migdal effect on the quenching factor can mimic the signal of a light z′ or light scalar mediator in coherent elastic neutrino-nucleus scattering experiments with reactor antineutrinos. it is imperative that the quenching factor of nuclei with low recoil energy thresholds be precisely measured close to threshold to avoid such confusion. this will also help in experimental searches of light dark matter. | coherent neutrino scattering and the migdal effect on the quenching factor |
a search for a light charged higgs boson, originating from the decay of a top quark and subsequently decaying into a charm quark and a strange antiquark, is presented. the data used in the analysis correspond to an integrated luminosity of 19.7 fb-1 recorded in proton-proton collisions at √{s}=8 tev by the cms experiment at the lhc. the search is performed in the process toverline{t}to {w}^{± }{bh}^{∓}overline{b} , where the w boson decays to a lepton (electron or muon) and a neutrino. the decays lead to a final state comprising an isolated lepton, at least four jets and large missing transverse energy. no significant deviation is observed in the data with respect to the standard model predictions, and model-independent upper limits are set on the branching fraction b(tto {h}+b) , ranging from 1.2 to 6.5% for a charged higgs boson with mass between 90 and 160 gev, under the assumption that b({h}+to cs)=100% . [figure not available: see fulltext.] | search for a light charged higgs boson decaying to coverline{s} in pp collisions at √{s}=8 tev |
potential applications of neutrino detection to nuclear security have been discussed since the 1970s. recent years have seen great progress in detector technologies based on inverse beta decay, with the demonstration of ton-scale surface-level detectors capable of high quality neutrino spectrum measurements. in 2017, coherent elastic neutrino nucleus scattering was experimentally confirmed with neutrinos from stopped pion decay, and there are a number of experiments aimed at seeing this process with reactor neutrinos. the large cross section and thresholdless nature of this reaction make it plausible to consider it for applications to nuclear security. here we present a first direct comparison of the two reaction modes. | reactor neutrino applications and coherent elastic neutrino nucleus scattering |
background: long-baseline experiments such as the planned deep underground neutrino experiment (dune) require theoretical descriptions of the complete event in a neutrino-nucleus reaction. since nuclear targets are used this requires a good understanding of neutrino-nucleus interactions. purpose: develop a consistent theory and code framework for the description of lepton-nucleus interactions that can be used to describe not only inclusive cross sections, but also the complete final state of the reaction. methods: the giessen-boltzmann-uehling-uhlenbeck (gibuu) implementation of quantum-kinetic transport theory is used, with improvements in its treatment of the nuclear ground state and of 2p2h interactions. for the latter an empirical structure function from electron scattering data is used as a basis. results: results for electron-induced inclusive cross sections are given as a necessary check for the overall quality of this approach. the calculated neutrino-induced inclusive double-differential cross sections show good agreement data from neutrino and antineutrino reactions for different neutrino flavors at miniboone and t2k. inclusive double-differential cross sections for microboone, nova, minerva, and lbnf/dune are given. conclusions: based on the gibuu model of lepton-nucleus interactions a good theoretical description of inclusive electron-, neutrino-, and antineutrino-nucleus data over a wide range of energies, different neutrino flavors, and different experiments is now possible. since no tuning is involved this theory and code should be reliable also for new energy regimes and target masses. | neutrino-induced reactions on nuclei |
the prospects of extracting new physics signals in coherent elastic neutrino--nucleus scattering (ce$\nu$ns) processes are limited by the precision with which the underlying nuclear structure physics, embedded in the weak nuclear form factor, is known. we present calculations of charge and weak nuclear form factors and ce$\nu$ns cross sections on $^{12}$c, $^{16}$o, $^{40}$ar, $^{56}$fe and $^{208}$pb nuclei. we obtain the proton and neutron densities, and charge and weak form factors by solving hartree--fock (hf) equations with a skyrme (ske2) nuclear potential. we validate our approach by comparing $^{208}$pb and $^{40}$ar charge form factor predictions with available elastic electron scattering data. since ce$\nu$ns experiments at stopped--pion sources are also well suited to measure inelastic charged--current and neutral--current neutrino--nucleus cross sections, we also present calculations for these processes, incorporating a continuum random phase approximation (crpa) description on top of the hf-ske2 picture of the nucleus. providing both coherent as well as inelastic cross sections in a consistent framework, we aim at obtaining a reliable and detailed comparison of the strength of these processes in the energy region below ~100 mev. furthermore, we attempt to gauge the level of theoretical uncertainty pertaining to the description of the $^{40}$ar form factor and ce$\nu$ns cross sections by comparing relative differences between recent microscopic nuclear theory and widely--used phenomenological form factor predictions. future precision measurements of ce$\nu$ns will potentially help in constraining these nuclear structure details that will in turn improve prospects of extracting new physics. | cross sections for coherent elastic and inelastic neutrino-nucleus scattering |
measurements of the fiducial inclusive and differential production cross sections of the higgs boson in proton-proton collisions at √{s } = 13 tev are performed using events where the higgs boson decays into a pair of w bosons that subsequently decay into a final state with an electron, a muon, and a pair of neutrinos. the analysis is based on data collected with the cms detector at the lhc during 2016-2018, corresponding to an integrated luminosity of 137 fb-1. production cross sections are measured as a function of the transverse momentum of the higgs boson and the associated jet multiplicity. the higgs boson signal is extracted and simultaneously unfolded to correct for selection efficiency and resolution effects using maximum-likelihood fits to the observed distributions in data. the integrated fiducial cross section is measured to be 86.5 ± 9.5 fb, consistent with the standard model expectation of 82.5 ± 4.2 fb. no significant deviation from the standard model expectations is observed in the differential measurements. | measurement of the inclusive and differential higgs boson production cross sections in the leptonic ww decay mode at √{s } = 13 tev |
the ν gen is new experiment at the kalinin nuclear power plant (knpp) for detection of coherent neutrino-ge nucleus elastic scattering. recent neutrino and dark matter search experiments have revolutionized the detection of rear events, and rear events with low energies, in particular. experiments have achieved sensitivities on the level of several events per hundred kg of detector material per day with energy thresholds from few hundred ev. this opens up a new unique possibility for experimental detection of neutrino-nucleus coherent scattering that has been considered to be impossible so far. the νgen project uses low threshold high-purity ge-detectors (hpge) developed by jinr (dubna, russia) in collaboration with bsi (baltic scientific instruments, riga, latvia) for creation of a setup designated for first observation of neutrino coherent scattering on ge. as a powerful neutrino source the experiment will use electron antineutrinos from one of the power-generating units (reactor unit #3) of the knpp. the coherent neutrino scattering will be observed using a differential method that compares 1) the spectra measured at the reactor operation and shut-down periods; 2) the spectra measured at different distances from the reactor core during the reactor operation. for a setup placed at a 10 m distance from the center of reactor core and with an energy threshold of 350 ev up to tens of events corresponding to neutrino coherent scattering on ge are expected to be detected per day in the constructed setup with four hpge low-energy-threshold detectors (~ 400 grams each). the setup sensitivity will be even more increased by using new detectors with total mass up to 5 kg. | the νgen experiment at the kalinin nuclear power plant |
isolating the scattering of longitudinal weak bosons at the lhc is an important tool to probe the electroweak symmetry breaking mechanism. separating polarizations of w and z bosons is complicated, because of non resonant contributions and interference effects. additional care is necessary when considering z bosons, due to the γ /z mixing in the coupling to charged leptons. we propose a method to define polarized signals in zz and w + z scattering at the lhc, which relies on the separation of weak boson polarizations at the amplitude level in monte carlo simulations. after validation in the absence of lepton cuts, we investigate how polarized distributions are affected by a realistic set of kinematic cuts (and neutrino reconstruction, when needed). the total and differential polarized cross sections computed at the amplitude level are well defined, and their sum reproduces the full results, up to non negligible but computable interference effects which should be included in experimental analyses. we show that polarized cross sections computed using the reweighting method are inaccurate, particularly at large energies. we also present two procedures which address the model independent extraction of polarized components from lhc data, using standard model angular distribution templates. | polarized vector boson scattering in the fully leptonic wz and zz channels at the lhc |
using an 185-kg nai[tl] array, coherent has measured the inclusive electron-neutrino charged-current cross section on i 127 with pion decay-at-rest neutrinos produced by the spallation neutron source at oak ridge national laboratory. iodine is one the heaviest targets for which low-energy (≤50 mev ) inelastic neutrino-nucleus processes have been measured, and this is the first measurement of its inclusive cross section. after a five-year detector exposure, coherent reports a flux-averaged cross section for electron neutrinos of 9.2-1.8+2.1×10-40 cm2. this corresponds to a value that is ∼41 % lower than predicted using the marley event generator with a measured gamow-teller strength distribution. in addition, the observed visible spectrum from charged-current scattering on i 127 has been measured between 10 and 55 mev, and the exclusive zero-neutron and one-or-more-neutron emission cross sections are measured to be 5.2-3.1+3.4×10-40 and 2.2-0.5+0.4×10-40 cm2, respectively. | measurement of electron-neutrino charged-current cross sections on 127i with the coherent nai ν e detector |
we construct a neutrino model of three twin neutrinos in light of the neutrino appearance excesses at lsnd and miniboone. the model, which includes a twin parity, naturally predicts identical lepton yukawa structures in the standard model and the twin sectors. as a result, a universal mixing angle controls all three twin neutrino couplings to the standard model charged leptons. this mixing angle is predicted to be the ratio of the electroweak scale over the composite scale of the higgs boson and has the right order of magnitude to fit the data. the heavy twin neutrinos decay within the experimental lengths into active neutrinos plus a long-lived majoron and can provide a good fit, at around the 4 σ confidence level, to the lsnd and miniboone appearance data while simultaneously satisfying the disappearance constraints. for the majorana neutrino case, the fact that neutrinos have a larger scattering cross section than antineutrinos provides a natural explanation to miniboone's observation of a larger antineutrino appearance excess. | three twin neutrinos: evidence from lsnd and miniboone |
in the near future, fundamental interactions at high-energy scales may be most efficiently studied via precision measurements at low energies. a universal language to assemble and interpret precision measurements is the so-called smeft, which is an effective field theory (eft) where the standard model (sm) lagrangian is extended by higher-dimensional operators. in this paper we investigate the possible impact of the dune neutrino experiment on constraining the smeft. the unprecedented neutrino flux offers an opportunity to greatly improve the current limits via precision measurements of the trident production and neutrino scattering off electrons and nuclei in the dune near detector. we quantify the dune sensitivity to dimension-6 operators in the smeft lagrangian, and find that in some cases operators suppressed by an o(30) tev scale can be probed. we also compare the dune reach to that of future experiments involving atomic parity violation and polarization asymmetry in electron scattering, which are sensitive to an overlapping set of smeft parameters. | future dune constraints on eft |
this paper reports a measurement by the t2k experiment of the νμ charged current quasielastic (ccqe) cross section on a carbon target with the off-axis detector based on the observed distribution of muon momentum (pμ) and angle with respect to the incident neutrino beam (θμ). the flux-integrated ccqe cross section was measured to be ⟨σ ⟩=(0.83 ±0.12 )×10-38 cm2 . the energy dependence of the ccqe cross section is also reported. the axial mass, maqe, of the dipole axial form factor was extracted assuming the smith-moniz ccqe model with a relativistic fermi gas nuclear model. using the absolute (shape-only) pμ-cos θμ distribution, the effective maqe parameter was measured to be 1.2 6-0.18+0.21 gev /c2 (1.4 3-0.22+0.28 gev /c2 ). | measurement of the νμ charged-current quasielastic cross section on carbon with the nd280 detector at t2k |
the planned dune experiment will have excellent sensitivity to the vector and axial couplings of the electron to the z boson via precision measurements of neutrino-electron scattering. we investigate the sensitivity of dune-prism, a movable near detector in the direction perpendicular to the beam line, and find that it will qualitatively impact our ability to constrain the weak couplings of the electron. we translate these neutrino-electron scattering measurements into a determination of the weak mixing angle at low scales and estimate that, with seven years of data taking, the dune near detector can be used to measure sin2θw with about 2% precision. we also discuss the impact of combining neutrino-electron scattering data with neutrino trident production at dune-prism. | measuring the weak mixing angle in the dune near-detector complex |
short distance reactor antineutrino experiments measure an antineutrino spectrum a few percent lower than expected from theoretical predictions. in this work we study the potential of low energy threshold reactor experiments in the context of a light sterile neutrino signal. we discuss the perspectives of the recently detected coherent elastic neutrino-nucleus scattering in future reactor antineutrino experiments. we find that the expectations to improve the current constraints on the mixing with sterile neutrinos are promising. we also analyze the measurements of antineutrino scattering off electrons from short distance reactor experiments. in this case, the statistics is not competitive with inverse beta decay experiments, although future experiments might play a role when compare it with the gallium anomaly. | the reactor antineutrino anomaly and low energy threshold neutrino experiments |
we propose an experimental setup to observe coherent elastic neutrino-atom scattering (ce ν as ) using electron antineutrinos from tritium decay and a liquid helium target. in this scattering process with the whole atom, that has not been observed so far, the electrons tend to screen the weak charge of the nucleus as seen by the electron antineutrino probe. the interference between the nucleus and the electron cloud produces a sharp dip in the recoil spectrum at atomic recoil energies of about 9 mev, reducing sizably the number of expected events with respect to the coherent elastic neutrino-nucleus scattering case. we estimate that with a 60 g tritium source surrounded by 500 kg of liquid helium in a cylindrical tank, one could observe the existence of ce ν as processes at 3 σ in 5 yr of data taking. keeping the same amount of helium and the same data-taking period, we test the sensitivity to the weinberg angle and a possible neutrino magnetic moment for three different scenarios: 60, 160, and 500 g of tritium. in the latter scenario, the standard model (sm) value of the weinberg angle can be measured with a statistical uncertainty of sin2 ϑwsm-0.016+0.015. this would represent the lowest-energy measurement of sin2ϑw, with the advantage of being not affected by the uncertainties on the neutron form factor of the nucleus as the current lowest-energy determination. finally, we study the sensitivity of this apparatus to a possible electron neutrino magnetic moment and we find that using 60 g of tritium it is possible to set an upper limit of about 7 ×10-13μb at 90% c.l., that is more than one order of magnitude smaller than the current experimental limit. | potentialities of a low-energy detector based on 4he evaporation to observe atomic effects in coherent neutrino scattering and physics perspectives |
point-contact p-type high-purity germanium detectors (ppc hpge) are particularly suited for detection of sub-kev nuclear recoils from coherent elastic scattering of neutrinos or light dark matter particles. while these particles are expected to interact homogeneously in the entire detector volume, specific classes of external background radiation preferably deposit their energy close to the semi-active detector surface, in which diffusion processes dominate that subsequently lead to slower rising pulses compared to the ones from the fully active bulk volume. dedicated studies of their shape are therefore highly beneficial for the understanding and the rejection of these unwanted events. this article reports about the development of a data-driven pulse shape discrimination (psd) method for the four 1 kg size ppc hpge detectors of the conus experiment in the kev and sub-kev regime down to 210 ev$_{\text{ee}}$. the impact of the electronic noise at such low energies is carefully examined. it is shown that for an acceptance of 90% of the faster signal-like pulses from the bulk volume, approx. 50% of the surface events can be rejected at the energy threshold and that their contribution is fully suppressed above 800 ev$_{\text{ee}}$. applied to the conus background data, such a psd rejection cut allows to achieve an overall (15-25)% reduction of the total background budget. the new method allows to improve the sensitivity of future conus analyses and to refine the corresponding background model in the sub-kev energy region. | pulse shape discrimination for the conus experiment in the kev and sub-kev regime |
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