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inverse beta decay (ibd) is the dominant mechanism of antineutrino scattering at energies below a few tens of mev. its cross section is currently considered to be known with uncertainty of a fraction of percent. here i point out that in the existing cross-section calculations the vector part of the hadronic current is not conserved, although its conservation is invoked to express the vector form factors by their electromagnetic counterparts. i obtain the ibd cross section in the most general case, with six contributing form factors, and then use theoretical arguments and experimental constraints to reduce their number. ensuring conservation of the vector current leads to the results which converges to previous calculations at energies of several mev but is appreciably lower near the reaction threshold. these findings suggest that the current estimate of the flux of geologically produced antineutrinos may be underestimated. the proposed search for light sterile neutrinos using a 144ce-144pr source is predicted to collect a lower event rate and to observe a spectral distortion independent of the distance from the source. in reactor-neutrino experiments, the predicted event rate is reduced—diminishing the size of the reported anomaly—and the positron spectra are altered. | improved estimate of the cross section for inverse beta decay |
a good understanding of the cross sections for neutrino interactions with nucleons and nuclei is crucial for neutrino oscillation studies, in addition to providing a tool for the exploration of nucleon and nuclear structures. the microboone liquid-argon time-projection-chamber (lartpc) experiment has been taking neutrino data with the booster neutrino beam at fermilab since 2015. the lartpc capabilities in track reconstruction, energy measurement, and particle identification allow us to probe interesting regions of neutrino-argon scattering cross sections and to probe the quark composition of the nucleon and test models of nuclear structure and final-state interactions. we present the current status of several on-going microboone cross section analyses, as well as plans for future measurements. | neutrino scattering studies in microboone |
we propose to observe and to study neutrino coherent scattering reaction at spallation neutron source accelerator facility of the oak ridge national laboratory (u.s.a.) using two-phase liquid xenon emission detector. we present expected detector rates for different experimental conditions. | investigation of coherent neutrino scattering at the spallation neutron source |
the neutron scatter camera (nsc) is a neutron spectrometer and imager that has been developed and improved by the sandia national laboratories for several years. built for special nuclear material searches, the instrument was configured by the design to reconstruct neutron sources within the fission energy range 1-10 mev. in this work, we present modifications that attempt to extend the nsc sensitivity to neutron energies in the range ∼10-200 mev and discuss the corresponding consequences for the event processing. we present simulation results that manifest important aspects of the nsc response to those intermediate energy neutrons. the simulation results also evidence that the instrument's spectroscopic capabilities severely deteriorate at those energies, mainly due to the uncertainties in measuring energy, time, and distance between the two neutron scattering interactions. this work is motivated by the need to characterize neutron fluxes at particle accelerators as they may represent important backgrounds for neutrino experiments. | extension of the neutron scatter camera sensitivity to the ∼10-200 mev neutron energy range |
the paper discusses the two-loop (nnlo) electroweak radiative corrections to the parity-violating moller scattering asymmetry induced by insertions to boxes of electron and neutrino mass operators (fermion self-energies), vertex functions and boson self-energies. the results will be relevant to the ultra-precise 11 gev moller experiment planned at the jefferson laboratory, which will measure the weak charge of the electron and search for new physics. the numerical estimations for the nnlo contribution to the cross section asymmetry are presented. | nnlo electroweak corrections for polarized moller scattering: one-loop insertions to boxes |
last year the coherent collaboration was able to measure for the first time the coherent elastic neutrino nucleus scattering (ce$\nu$ns). neutrinos within the right energy range can be produced in large quantities at accelerator facilities via pion decay at rest ($\pi$dar) and used to measure ce$\nu$ns. this new channel opens several, interesting possibilities: studying the ce$\nu$ns spectrum it will be possible, for example, to search for physics beyond the standard model, looking for deviations from the predictions of the electroweak theory; it can also give important inputs for the understanding of core collapse supernovas, where neutrino-nucleus interactions and, more generally, collective neutrino behavior play a crucial role. using ce$\nu$ns it is also possible to measure precisely the electroweak form factor for a large number of different nuclei, extracting information on the neutron distribution inside the nucleus as well. in this presentation i will focus on the last aspect: i will calculated the precision that can be achieved in such kind of experiment, investigating in particular the effects of the low-energy threshold and the systematic errors on the quenching factor. the expected precision will be calculated using the helm model and also with a model-independent approach. | measuring the neutron distribution from coherent elastic neutrino nucleus scattering |
the microboone neutrino experiment at fermilab is constructing a liquid-argon time-projection chamber for the booster neutrino beam to study neutrino oscillations and interactions with nucleons and nuclei, starting in 2014. we describe the experiment and focus on its unique abilities to measure cross sections at low values of q2. in particular, the neutral-current elastic scattering cross section is especially interesting, as it is sensitive to the contribution of the strange sea quark spin to the angular-momentum of the nucleon, δs. implications for dark-matter searches are discussed. | improving dark matter searches by measuring the nucleon axial form factor: perspectives from microboone |
we identify a number of crystalline structures with promising characteristics to serve as a detection medium for a novel dark matter (dm) detector with a low threshold energy. a detector of this kind can be specifically useful in application requiring the detection of nuclear recoils, such as in direct detection of low mass dm, coherent neutrino scattering and neutrons. we describe a broad band, high sensitivity optical setup designed and constructed for the purpose of this search and future investigations of specific crystals. we report on the fluorescent signals produced from exposure to low doses of neutrons and $\gamma$ rays and find potential targets in quartz, sapphire, lif, caf$_{2}$ and baf$_{2}$. these crystals and specific signals will be the subject of further study to establish the various traits relevant for a full scale dm detector. in this paper we identify the most interesting signals that will be promoted to significantly more detailed studies, including their production mechanism. | wide band spectroscopic response of monocrystallines to low dose neutron and gamma radiation |
electron spin flip in atoms or ions can cause neutrino pair emission, which provides a method to explore still unknown important neutrino properties by measuring spectrum of emitted photon in association, when electroweak rates are amplified by a phase coherence among participating atoms. two important remaining neutrino issues to be determined are the absolute neutrino mass (or the smallest neutrino mass in the three-flavor scheme) and the nature of neutrino masses, either of dirac type or of majorana type. use of raman scattered photon was recently proposed as a promising tool for this purpose. in the present work we continue along this line to further identify promising ion targets in crystals, calculate neutrino pair emission rates, and study how to extract neutrino properties from raman scattered photon angular distribution. divalent lanthanoid ions in crystals, in particular sm$^{2+}$, are the most promising, due to (1) its large number density, (2) sharp optical lines, (3) a variety of available ionic levels. rejection of amplified quantum electrodynamic backgrounds is made possible to controllable levels by choosing a range of raman trigger direction, when sm$^{2+}$ sites are at o$_h$ inversion center of host crystals such as srf$_2$. | divalent lanthanoid ions in crystals for neutrino mass spectroscopy |
a multi-functional teaching apparatus has been developed for α and β spectroscopy utilizing a solid-state detector and associated electronics. the possible experiments include conventional measurements to determine α and β decay energies, half lives, characteristic energy loss of nuclear particles in matter, and limits on the β-neutrino mass set from endpoints in β-decay spectra. in addition, the relativistic mass increase of β particles is verified using a high-efficiency, axially symmetric permanent ring-magnet β spectrometer. the basic apparatus also can be adapted for experiments in rutherford scattering and other nuclear measurements. | a multi-functional apparatus for α and β spectroscopy utilizing a permanent ring-magnet β spectrometer |
the nova neutrino oscillation experiment uses the genie event generator to predict neutrino interactions in its detectors. recent data, recent reanalysis of extant data, and continued development of theoretical models have brought to light deficiencies in the default genie cross section model, which in turn impact the predicted spectra used to infer oscillation parameters. we discuss modifications to genie version 2.12.2, motivated by these various sources, which culminate in a tune using nova near detector muon neutrino scattering data. this tuned version of the generator is used for the predictions in nova's far detector oscillation analyses. | neutrino interaction model tuning at nova |
in accelerator neutrino experiments, neutrino-mixing parameters are extracted from the counting rates of quasielastic (anti)neutrino scattering on nuclear targets. we discuss the uncertainties of these rates in the model approach with an energy-dependent (or running) axial mass of the nucleon. | quasielastic neutrino-nucleus interactions in the empirical model of running axial mass of the nucleon |
icarus is the largest liquid argon tpc detector ever built (∼ 600 ton lar mass). it was smoothly operated underground at the lngs laboratory in gran sasso since summer 2010, up to june 2013, collecting data with the cngs beam and with cosmics. icarus is internationally considered as a milestone towards the realization of next generation of massive detectors (∼ tens of ktons) for neutrino and rare event physics. it permits, as a unique feature, the unambiguous identification of νe events. in particular an update of the experimental search for a νe signal in the lsnd anomaly region in the cngs beam will be here presented with the full statistics. the published result strongly limits the window of opened options for the lsnd anomaly, reducing the remaining effect to a narrow region centered around (δm2 ,sin2 (2 θ)) = (0.5 ev2 , 0.005) where there is an overall agreement (90% cl) between the present icarus limit, the published limits of karmen and the published positive signals of lsnd and miniboone collaborations. moreover, new results will be shown concerning the analysis of a cngs beam-related stopping muon sample with the purpose of the momentum reconstruction through multiple coulomb scattering. finally, the most recent result on the argon purity analysis will be presented, which allowed to reach impressive results in terms of argon purity and a free electron lifetime exceeding 12 ms, corresponding to about 25 parts per trillion of o2-equivalent contamination: a milestone for any future project involving lar-tpcs and the development of higher detector mass scales. | some recent results from the icarus experiment |
new and more precise measurements of neutrino cross sections in the few gev energy region have renewed interest in a better understanding of electroweak interactions on nucleons and nuclei. this interest comes from neutrino oscillation experiments and their need to reduce systematic errors. neutrino fluxes used in contemporary long and short baseline experiments (k2k, t2k, minos, nova, miniboone, minerva, …) are peaked in the 1-5 gev energy domain. in this context, i will present some details about the theoretical development in the description of (anti)neutrino-induced quasielastic scattering and the role of multi-nucleon mechanisms. | theoretical challenges in neutrino scattering studies |
non-standard neutrino-nucleon interaction is formulated and explored within the energy range of quasi-elastic scattering. in particular, the study focuses on the neutral-current elastic (anti)neutrino scattering off nucleons described by the exotic reactions $\nu_\alpha ({\bar \nu}_\alpha) + n \rightarrow \nu_\beta ({\bar \nu}_\beta) + n $ and $ \nu_\alpha ({\bar \nu}_\alpha) + p \rightarrow \nu_\beta ({\bar \nu}_\beta) + p$, which provide corrections to the dominant standard model processes. in this context, it is shown that the required exotic nucleon form factors may have a significant impact on the relevant cross sections. besides cross sections, the event rate is expected to be rather sensitive to the magnitude of the lepton-flavour violating parameters resulting in an excess of events. the overlap of non-standard interactions and strange quark contributions, in the region of few gev neutrino energies, is also examined. the formalism is applied for the case of the relevant neutrino-nucleon scattering experiments (lsnd, miniboone, etc.) and motivates the notion that such facilities have high potential to probe nsi. | impact of non-standard interactions on neutrino-nucleon scattering |
we compute the energy spectrum of photons {and neutrinos} produced by the unwinding of a scaling distribution of cosmic textures, and discuss the implications for the spectrum of high energy cosmic rays, and for cmb spectral distortions. textures lead to a contribution to the photon flux which scales as e3 f(e) ~ e3/2. hence, the tightest constraints on the texture model come from the highest energies from which primordial photons can reach us without being scattered by the cmb and other foregrounds. textures lead to both μ type and y type distortions. while the constraints on the texture model coming from the current cobe bounds are weaker than the bounds from the angular power spectrum of the cmb, future surveys such as pixie can lead to stronger bounds. {the high energy neutrino flux is constrained by data from the pierre auger experiment and yields a bound on the energy scale of textures which is competitive with cmb bounds.} | cosmic rays and spectral distortions from collapsing textures |
in this paper, we analyze the theoretically possible scenario beyond the standard model in order to show how the presence of the exotic scalar, tensor, {v}+{a} weak interactions in addition to the standard vector-axial ({v}-{a}) ones may help to distinguish the dirac from majorana neutrinos in the elastic scattering of an (anti)neutrino beam off the unpolarized electrons in the relativistic limit. we assume that the incoming (anti)neutrino beam comes from the polarized muon decay at rest and is the left-right chiral superposition with assigned direction of the transversal spin polarization with respect to the production plane. our analysis is carried out for the flavour (current) neutrino eigenstates. it means that the transverse neutrino polarization estimates are the same both for the dirac and majorana cases. we display that the azimuthal asymmetry in the angular distribution of recoil electrons is generated by the interference terms between the standard and exotic couplings, which are proportional to the transversal (anti)neutrino spin polarization and independent of the neutrino mass. this asymmetry for the majorana neutrinos is larger than for the dirac ones. we also indicate the possibility of utilizing the azimuthal asymmetry measurements to search for the new cp-violating phases. our study is based on the assumption that the possible detector (running for 1 year) has the shape of a flat circular ring, while the intense neutrino source is located in the centre of the ring and polarized perpendicularly to the ring. in addition, the large low-threshold, real-time detector is able to measure with a high resolution both the polar angle and the azimuthal angle of outgoing electron momentum. our analysis is model-independent and consistent with the current upper limits on the non-standard couplings. | azimuthal asymmetry of recoil electrons in neutrino-electron elastic scattering as signature of neutrino nature |
the coherent collaboration is realizing a long term neutrino physics research program. the main goals of the program are to detect and study elastic neutrino-nucleus scattering (ceνns). this process is predicted by standard model but it has never been observed experimentally because of the very low energy of the recoil nucleus. coherent is using different detector technologies: csi[na] and nai scintillator crystals, a single-phase liquid ar and a ge detectors. the placement of all the detector setups is in the basement of the spallation neutron source (sns) at oak ridge national laboratory (ornl). the current status of the coherent experimental program is presented. | coherent experiment: current status |
low energy threshold reactor experiments have the potential to give insight into the light sterile neutrino signal provided by the reactor antineutrino anomaly and the gallium anomaly. in this work we analyze short baseline reactor experiments that detect by elastic neutrino electron scattering in the context of a light sterile neutrino signal. we also analyze the sensitivity of experimental proposals of coherent elastic neutrino nucleus scattering (cenns) detectors in order to exclude or confirm the sterile neutrino signal with reactor antineutrinos. | neutrino scattering and the reactor antineutrino anomaly |
direct dark matter searches are nowadays one of the most exciting research topics. several experimental efforts are concentrated on the development, construction, and operation of detectors looking for the scattering of target nuclei with weakly interactive massive particles (wimps). the measurement of the direction of wimp-induced nuclear recoils is a challenging strategy to extend dark matter searches beyond the neutrino floor and provide an unambiguous signature of the detection of galactic dark matter. current directional experiments are based on the use of gas tpc whose sensitivity is strongly limited by the small achievable detector mass. we present an innovative directional experiment based on the use of a solid target made by newly developed nuclear emulsions and read-out systems reaching a position resolution of the order of 10 nm. | newsdm: nuclear emulsions for wimp search with directional measurement |
next generation direct dark matter detectors will have the sensitivity to detect neutrinos from several sources, among which atmospheric and diffuse supernova neutrinos, through the standard model reaction of coherent elastic neutrino scattering on nucleus. this reaction represents an irreducible background that can be expressed as a limit in the weakly interacting massive particles parameters plane. this limit is known as the “neutrino floor” and it has been obtained by other authors considering standard hypotheses for the neutrino-nucleus form factor and for the coherence of the scattering process. since the coherent scattering has never been observed experimentally, it is licit to relax some hypotheses in the differential cross section and to evaluate the effect of such modifications on the neutrino floor prediction. in this contribution, we show a more accurate neutrino-nucleus form factor and we discuss the coherence hypothesis of the process in two extreme cases, namely the total coherence and the total decoherence regime. we derive the neutrino background event rate under these new assumptions, considering xenon as a target. the differences between the number of neutrino events and the implication for the next generation dark matter detectors, such as xenon1t/xenonnt, lz and darwin, are discussed. | impact of neutrino background prediction for next generation dark matter xenon detector |
increasing the distance from which an antineutrino detector is capable of monitoring the operation of a registered reactor, or discovering a clandestine reactor, strengthens the non-proliferation of nuclear weapons treaty. this paper presents calculations of reactor antineutrino interactions from quasi-elastic neutrino-proton scattering and elastic neutrino-electron scattering in a water-based detector operated $\gtrsim10$ km from a commercial power reactor. it separately calculates signal from the proximal reactor and background from all other registered reactors. the main results are differential and integral interaction rates from the quasi-elastic and elastic processes. there are two underground facilities capable of hosting a detector ($\sim1$ kt h$_2$o) project nearby ($l\sim20$ km) an operating commercial reactor ($p_{th}\sim3$ gw). these reactor-site combinations, which are under consideration for project watchman, are perry-morton on the southern shore of lake erie in the united states and hartlepool-boulby on the western shore of the north sea in england. the signal rate from the proximal reactor is about five times greater at the morton site than at the boulby site due to shorter reactor-site separation distance, larger reactor thermal power, and greater neutrino oscillation survival probability. although the background rate from all other reactors is larger at morton than at boulby, it is a smaller fraction of the signal rate from the proximal reactor at morton than at boulby. moreover, the hartlepool power plant has two cores whereas the perry plant has a single core. the boulby site, therefore, offers an opportunity for remotely monitoring the on/off cycle of a reactor core under more stringent conditions than does the morton site. | evaluating reactor antineutrino signals for watchman |
the net contribution of the strange quark spins to the proton spin, $\delta s$, can be determined from neutral current elastic neutrino-proton interactions at low momentum transfer combined with data from electron-proton scattering. the probability of neutrino-proton interactions depends in part on the axial form factor, which represents the spin structure of the proton and can be separated into its quark flavor contributions. low momentum transfer neutrino neutral current interactions can be measured in microboone, a high-resolution liquid argon time projection chamber (lartpc) in its first year of running in the booster neutrino beamline at fermilab. the signal for these interactions in microboone is a single short proton track. we present our work on the automated reconstruction and classification of proton tracks in lartpcs, an important step in the determination of neutrino- nucleon cross sections and the measurement of $\delta s$. | exploring nucleon spin structure through neutrino neutral-current interactions in microboone |
electron energy and angular distributions in the process of low-energy elastic neutrino-electron scattering are treated in the free-electron approximation. the effects of the millicharges, magnetic, electric, and anapole moments of massive neutrinos along with the flavor change of neutrinos traveling from the source to the detector are taken into account under the assumption of three-neutrino mixing. the footprints of neutrino electromagnetic interactions in the electron energy and angle distributions are discussed. | electromagnetic interactions of neutrinos in processes of low-energy elastic neutrino-electron scattering |
we examine neutral-current quasi-elastic neutrino-nucleus reactions on 12c and 208pb targets. we use the relativistic mean field theory approach to describe the nuclear dynamics. we compute the cross sections for the scattering of 150, 500 and 1000 mev neutrinos on a 12c target and study the effect of the strange-quark content of the nucleon which appears in these reactions via the isoscalar weak current. we compare our results with the data of the miniboone experiment for mineral oil (ch2). we also calculate the cross section for the quasi-elastic neutron knockout reaction of 20-60 mev neutrinos on a 208pb target which is relevant to plans to use lead as a target material in future supernova neutrino detectors. | quasi-elastic neutrino reactions on carbon and lead nuclei |
muon beams of low emittance provide the basis for the intense, well characterised neutrino beams of a neutrino factory and for multi-tev lepton-antilepton collisions at a muon collider. the international muon ionization cooling experiment (mice) will demonstrate ionization cooling, the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam. mice was constructed in a series of steps. data were taken in 2016 and 2017 in the step~iv configuration which was optimised for studying the properties of liquid hydrogen and lithium hydride. preliminary results from ongoing analyses will be described. | recent results from mice on multiple coulomb scattering and energy loss |
[background] long-baseline experiments such as t2k, nova or 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] one of the dominant reaction channels in neutrino-nucleus interactions is pion production. this paper aims for a coherent view on all charged current charged pion production data that are avaible from the experiments miniboone, the near detector experiment at t2k and minerva. [methods] pion production is treated through excitations of nucleon resonances, including background terms, and deep inelastic scattering. the final state interactions of the produced pions are described within the giessen-boltzmann-uehling-uhlenbeck (gibuu) implementation of quantum-kinetic transport theory. [results] results are given for miniboone, the near detector experiment at t2k and for minerva. while the theoretical results for miniboone differ from the data both in shape and magnitude, their agreement both with the t2k and the minerva data is good for all pion and lepton observables. predictions for pion spectra are shown for microboone and nova. [conclusions] based on the gibuu model of lepton-nucleus interactions a consistent, good theoretical description of cc charged pion production data from the t2k nd and the minerva experiments is possible, without any parameter tunes. the miniboone data cannot be reproduced. | muon-neutrino-induced charged current pion production on nuclei |
we study the potential of a detector based on ccd sensors (connie experiment) to study neutrino oscillations to sterile states using reactor neutrinos. we calculate the number of events expected in a 1 kg detector and determine the sensitivity to oscillations νe → νs in the δ m412 vs. sin2 θes parameter space for various exposures. the sensitivity is compared with the regions excluded by the daya bay experiment under the assumption θ 24 = θ 34 = 0. this work was carried out independently of the connie collaboration using published information, and its results are not official. | potential of ccds for the study of sterile neutrino oscillations via coherent neutrino-nucleus elastic scattering |
nuwro is a neutrino monte carlo generator developed at the wrocław university and used in many studies related with oscillation and cross section experiments. the main focus is on the 1 gev energy region but a wide spectrum of neutrino energies is covered, from 100 mev to tev energies. nuwro is well known for being very effective and friendly used, but it has all the functionalities needed for a use in neutrino experiments: can be run with realistic neutrino fluxes and is equipped with detector interface. recent nuwro upgrades include an improved description of secondary hadron interactions within custom made intranuclear cascade model. a careful comparison with electron scattering experiments shows that nuwro reproduces the experimental data for nuclear transparency. an attempt is made to estimate an uncertainty in evaluation of nucleon mean free path inside nucleus and its impact on understanding of recent measurements of proton knock-out cross section in neutrino experiments. | nuwro - neutrino monte carlo event generator |
we present the results of a recent study of meson-exchange two-body currents in lepton-nucleus inclusive scattering at various kinematics and for different nuclei within the relativistic fermi gas model. we show that the associated nuclear response functions at their peaks scale as $a k_f^2$, for fermi momentum $k_f$ going from 200 to 300 mev/c and momentum transfer $q$ from $2k_f$ to 2 gev/c. this behavior is different from what is found for the quasielastic response, which scales as $a/k_f$. this result can be valuable in the analyses of long-baseline neutrino oscillation experiments, which need to implement these nuclear effects in monte carlo simulations for different kinematics and nuclear targets. | nuclear dependence of the 2p2h electroweak response in the relativistic fermi gas model |
experiments using nuclei to probe new physics beyond the standard model, such as neutrinoless ββ decay searches testing whether neutrinos are their own antiparticle, and direct detection experiments aiming to identify the nature of dark matter, require accurate nuclear physics input for optimizing their discovery potential and for a correct interpretation of their results. this demands a detailed knowledge of the nuclear structure relevant for these processes. for instance, neutrinoless ββ decay nuclear matrix elements are very sensitive to the nuclear correlations in the initial and final nuclei, and the spin-dependent nuclear structure factors of dark matter scattering depend on the subtle distribution of the nuclear spin among all nucleons. in addition, nucleons are composite and strongly interacting, which implies that many-nucleon processes are necessary for a correct description of nuclei and their interactions. it is thus crucial that theoretical studies and experimental analyses consider β decays and dark matter interactions with a coupling to two nucleons, called two-nucleon currents. | nuclear physics insights for new-physics searches using nuclei: neutrinoless ββ decay and dark matter direct detection |
neutrinos are a nearly massless, neutral particle in the standard model that only interact via the weak interaction. experimental confirmation of neutrino oscillations, in which a neutrino created as a particular type (electron, muon or tau) can be observed as a different type after propagating some distance, earned the 2015 nobel prize in physics. neutrino oscillation experiments rely on accurate measurements of neutrino interactions with matter, such as that presented here. neutrinos also provide a unique probe of the nucleus, complementary to electron scattering experiments. this thesis presents a measurement of the charged-current inclusive cross section for muon neutrinos and antineutrinos in the energy range 2 to 50 gev with the minerva detector. minerva is a neutrino scattering experiment in the numi neutrino beam at fermilab, near chicago. a cross section measures the probability of an interaction occurring, measured here as a function of neutrino energy. to extract a cross section from data, the observed rate of interactions is corrected for detector efficiency and divided by the number of scattering nucleons in the target and the flux of neutrinos in the beam. the neutrino flux is determined with the low- v method, which relies on the principle that the cross section for interactions with very low recoil energy is nearly constant as a function of neutrino energy. the measured cross section is compared with world data. | measurement of neutrino and antineutrino charged-current inclusive cross sections with the minerva detector |
we present an overview of neutrino-nucleus scattering at low energies with cross sections obtained within a continuum random phase approximation (crpa) formalism. we highlight potential applications of beta-beam neutrino experiments for neutrino astrophysics. our calculations are compared with miniboone data at intermediate energies. | low-energy neutrino-nucleus interactions and beta-beam neutrino |
good understanding of the cross sections for (anti)neutrino scattering off nuclear targets in the few-gev energy region is a prerequisite for the correct interpretation of results of ongoing and planned oscillation experiments. to clarify a possible source of disagreement between recent measurements of the cross sections on carbon, we analyze the available data within an approach based on the realistic spectral function of carbon, treating neutral-current elastic (nce) and charged-current quasielastic (ccqe) processes on equal footing. we show that the axial mass from the shape analysis of the miniboone data is in good agreement with the results reported by the bnl e734 and nomad collaborations. however, the combined analysis of the nce and ccqe data does not seem to support the contribution of multinucleon final states being large enough to explain the normalization of the miniboone-reported cross sections. | consistent analysis of neutral- and charged-current (anti)neutrino scattering off carbon |
dark matter represents one of the most sought after discoveries in physics, and leading theories predict that extremely low-background detectors could be sensitive to nuclear recoils from dark matter interactions. the pico collaboration uses bubble chambers to look for the energy deposition from such an interaction. however, unknown backgrounds have plagued the pico detectors for many years. i work to uncover the source(s) of these mysterious backgrounds with the goal of eliminating them using, amongst other tools, various small-scale bubble chamber detectors and a xenon time projection chamber at fermilab. currently, all dark matter detection experiments treat electron recoils the same way, whether they come from neutrino or compton scatters, beta-decay, or photoabsorption. my work indicates that this treatment is over-simplistic and results in a breakdown of existing calibration schemes. i have applied my knowledge of backgrounds to the pico-60 detector as run coordinator. the resulting background-free month-long dark matter search represents the first background-free operation of a bubble chamber dark matter detector at the 40 liter scale, and is the most sensitive direct detection experiment to spin-dependent wimp-proton dark matter interactions to date. specifically, for 30 gev c-2 dark matter, wimp-proton spin-dependent cross sections larger than 3.4 x 10-41 cm2 are excluded at the 90% confidence level. | eliminating backgrounds in the search for dark matter with the pico-60 bubble chamber |
neutrino-induced pion production constitutes an important contribution to neutrino-nucleus scattering cross sections at intermediate energies. a deep understanding of this process is mandatory for a correct interpretation of neutrino-oscillation experiments. we aim at contributing to the ongoing effort to understand the various experimental results obtained by different collaborations in a wide range of energies. in particular, in this work we analyze recent miniboone and minerνa charged-current neutrino 1-π production data. we use a relativistic theoretical approach which accounts for resonant and non-resonant 1-π production contributions. | neutrino-induced 1-π production |
we report herein the first-ever measurement of a cross-section for an exclusive state in electron neutrino scattering at the gev scale, which was made using the minernua detector in the numi neutrino beam at fermilab. we present the electron neutrino ccqe differential cross-sections, which are averaged over neutrinos of energies 1-10 gev (with mean energy of about 3 gev), in terms of various kinematic variables: final-state electron angle, final-state electron energy, and the square of the four-momentum transferred to the nucleus by the neutrino, q2. we also provide a total cross-section vs. neutrino energy. while our measurement of this process is found to be in agreement with the predictions of the genie event generator, we also report on an unpredicted photon-like process we observe in a similar kinematic regime. the absence of this process from models for neutrino interactions is a potential stumbling block for future on-axis neutrino oscillation experiments. we include kinematic and particle species identification characterizations which can be used in building models to help address this shortcoming. | measurement of the charged-current quasi-elastic cross-section for electron neutrinos on a hydrocarbon target |
in this paper, we compute the charged current (cc) cross section of the background processes bar{ν }μ a to μ+ (a - 1)n'π which are involved in the measurement of the oscillation probability p(bar{ν }μto bar{ν }e), for the cp-mirror processes of νμ → νe. we develop a model that takes into account: binding effects, nucleon smearing, and final state interactions (fsi) between nucleons-pions and the residual nucleus. it was also suitable in describing other channels as ν μ a to μ- (a - 1)n'π , keeping covariance, gauge invariance and partially unitarity. our calculations are compared with other dynamical models that have introduced the δ(1232) resonance but inconsistently, and contrasted with experimental data obtained at cern ps in gargamell chamber. | incoherent pion production in antineutrino-nucleus scattering within a fermi smearing approach |
next-generation neutrino oscillation experiments, such as dune and hyper-kamiokande, hope to measure charge-parity (cp) violation in the lepton sector. in order to do this, they must dramatically reduce their current levels of uncertainty, particularly those due to neutrino-nucleus interaction models. as cp violation is a measure of the difference between the oscillation properties of neutrinos and antineutrinos, data about how the less-studied antineutrinos interact is especially valuable. we present the minerva experiment's first double-differential scattering cross sections for antineutrinos on scintillator, in the few-gev range relevant to experiments such as dune and nova. we also present total antineutrino-scintillator quasi-elastic cross sections as a function of energy, which we compare to measurements from previous experiments. as well as being useful to help reduce oscillation experiments' uncertainty, our data can also be used to study the prevalence of various correlation and final-state interaction effects within the nucleus. we compare to models produced by different model generators, and are able to draw first conclusions about the predictions of these models. | measurement of the antineutrino double-differential charged-current quasi-elastic scattering cross section at minerva |
precise low-energy measurements in nuclear beta-decay provide constraints on possible physics beyond the standard model complementary to high-energy collider experiments. this thesis describes the most precise measurement of the positron asymmetry from a polarized nucleus to date. at the triumf neutral atom trap, atoms of the positron emitter 37k are confined in an alternating-current magneto-optical trap and spin-polarized to 99.13(9)% via optical pumping. the use of atom-trapping techniques allow for an exceptionally open geometry with the decay products escaping the trapping region unperturbed by the trapping potential. the emitted positrons are detected in a pair of symmetric detectors placed along the polarization axis to measure the asymmetry. the analysis was performed blind and considers beta-scattering and other systematic effects. the result, abeta (0) = -0.5707 +/- 0.0018, places limits on the mass of a hypothetical w boson coupling to right-handed neutrinos to be > 300gev/c 2 at zero-mixing as well as contributes to an independent determination of the vud element of the ckm matrix. | precise measurement of the beta-asymmetry in the decay of magneto-optically trapped, spin-polarized 37k |
among the direct search experiments for weakly interacting massive particle (wimp) dark matter, the dama experiment observed an annual modulation signal interpreted as wimp interactions with a significance of 9.2σ. recently, jonathan davis claimed that the dama modulation may be interpreted on the basis of the neutron scattering events induced by the muons and neutrinos together. we tried to simulate the neutron backgrounds at the gran sasso and yangyang laboratory with and without the polyethylene shielding to quantify the effects of the ambient neutrons on the direct detection experiments based on the crystals. | a simulation-based study of the neutron backgrounds for nai dark matter experiments |
x-ray computed tomography (ct) has an indispensable role in constructing 3d images of objects made from light materials. however, limited by absorption coefficients, x-rays cannot deeply penetrate materials such as copper and lead. here we show via simulation that muon beams can provide high resolution tomographic images of dense objects and of structures within the interior of dense objects. the effects of resolution broadening from multiple scattering diminish with increasing muon momentum. as the momentum of the muon increases, the contrast of the image goes down and therefore requires higher resolution in the muon spectrometer to resolve the image. the variance of the measured muon momentum reaches a minimum and then increases with increasing muon momentum. the impact of the increase in variance is to require a higher integrated muon flux to reduce fluctuations. the flux requirements and level of contrast needed for high resolution muon computed tomography are well matched to the muons produced in the pion decay pipe at a neutrino beam facility and what can be achieved for momentum resolution in a muon spectrometer. such an imaging system can be applied in archaeology, art history, engineering, material identification and whenever there is a need to image inside a transportable object constructed of dense materials. | high resolution muon computed tomography at neutrino beam facilities |
charged-current quasi-elastic (ccqe) neutrino scattering is the signal channel for sterile neutrino oscillation experiments. recent cross-section measurements have made it clear that the current understanding of this channel in the few-gev region is incomplete, and several sophisticated theoretical models have been proposed to tackle this issue, although it is not clear which model best describes the global dataset. in this paper we argue that the current uncertainty surrounding ccqe cross-sections is a serious problem for experiments seeking to produce sterile neutrino limits. we perform a sterile neutrino analysis with published minerva data as an illustrative example. we highlight the need for caution in interpreting sterile neutrino limits given the context of incomplete cross-section model information. | effect of cross-section models on the validity of sterile neutrino mixing limits |
we discuss nuclear effects on neutrino-nuclear interactions in a wide kinematical range from shallow to deep inelastic scattering (dis) region. there is necessity from neutrino communities to have precise neutrino-nucleus cross sections for future measurements on neutrino oscillations and leptonic cp violation. we try to create a model to calculate neutrino cross sections in the wide kinematical range, from quasi-elastic scattering and resonance productions to the dis. in this article, nuclear modifications of structure functions are mainly discussed, and a possible extension to the q2 → 0 region is explained. we also comment on the transition region between baryon resonances and the dis. there are ongoing experimental efforts on nuclear modifications of structure functions or parton distribution functions such as by pa reactions at rhic and lhc, drell-yan measurements at fermilab, minerνa neutrino dis, and charged-lepton dis at jlab. | nuclear effects in deep inelastic scattering and transition region |
germanium detectors with sub-kev sensitivities [1, 2, 3] offer a unique opportunity to study neutrino interactions and properties [4] as well as to search for light wimp dark matter [5, 6]. the texono and cdex collaborations have been pursuing this research program at the kuo-sheng neutrino laboratory in taiwan and in the china jinping underground laboratory in china. we will present highlights of the detector r&d program which allow us to experimental probe this new energy window. the results, status and plans of our neutrino physics program will be discussed, with focus on the quest on neutrino-nucleus coherent scattering. | neutrino and dark matter physics with sub-kev germanium detectors |
for low-mass dark matter search, an experiment with a cylindrical 1kg undoped csi crystal coupled directly to two photomultiplier tubes at about 77k was conducted and a light yield of 26.0+/-0.4 photoelectrons per kev electron-equivalent was achieved. the presumed prototype consisted of 10kg undoped csi or nai scintillation crystals directly coupled with sipm arrays operated at 77k was assumed to have a much higher light yield compared to the coherent csi(na) detector. this eliminated the concern of self light absorption in large crystals raised in some of the early studies. for neutrino detection, the light yield of an undoped csi crystal at about 77 kelvin was measured to be 33.5+/-0.7 pe per kevee in the energy range of [13, 60] kevee using x and γ-rays from an 241am radioactive source. based on this experimental result, the performance of 10kg cryogenic inorganic scintillating crystals coupled to sipm arrays to probe non-standard neutrino interactions (nsis) through the detection of coherent elastic neutrino-nucleus scatterings (cevns) at the spallation neutron source (sns), oak ridge national laboratory (ornl), was examined in detail. this work is supported by the nsf award phy-1506036, and the grant-in-aid for encouragement of young scientists (b), no. 26800122, mext, japan. the office of research at the university of south dakota. computations supporting this project were performed on high performance computing systems at the university of south dakota, funded by nsf award oac-1626516. | prospect of undoped inorganic crystals at 77 kelvin for low-mass dark matter search and neutrino detection at spallation neutron source |
the electrons for neutrinos project (e4nu) at the thomas jefferson national accelerator facility (jlab) uses wide phase space exclusive electron scattering data from past and future experiments on nuclear targets with the clas and clas12 detector systems to obtain a comprehensive understanding of the interaction of leptons with matter. data from jlab provides us with the means to constrain the available theoretical tools that are crucial in modeling the neutrino-nucleus interaction, and thus play a key role in the precise determination of the physics observables from neutrino-nucleus interactions measured at current and future neutrino experimental facilities, including microboone, minerva, dune and t2k. we will discuss the next phase of the e4nu project, taking new dedicated data with clas12 at jlab. we will take data with 1, 2, 4, and 6 gev beams, on deuterium, oxygen, carbon and argon targets, greatly expanding the available data. the first phase of this experiment will take place in fall 2021. | electrons for neutrinos: new experiments at jefferson lab |
there has been recent interest in low energy, high luminosity polarized electron beams for studies of parity-violating (pv) electron scattering, such as the mesa accelerator at mainz or an upgraded fel facility at jefferson lab. accurate measurements of the pv asymmetry in elastic electron scattering from nuclei can be used to determine standard model couplings, such as the weak-mixing angle or higher-order radiative corrections, as well as to extract specific information on the nuclear and nucleon structure. to this end, low uncertainties are required from modelling some confounding nuclear and nuclear structure effects, including isospin mixing, nucleon strangeness content or coulomb distortion of electron wave functions. we estimate the sizes and theoretical uncertainties of such effects for a carbon 12 target. an experimental precision in the pv asymmetry of a few tenths of a percent may be reachable under certain kinematic conditions, that are also discussed for the same nuclear target. this high precision pv asymmetry in elastic electron scattering can also be used to relate in a very simple manner the elastic electron-nucleus scattering cross section with the elastic neutrino-nucleus cross section. this novel relationship allows us to exploit experimentally well-determined quantities to predict unknown or recently measured observables, such as coherent neutrino-nucleus cross sections. this idea can be extended to link electron scattering to an even more uncertain magnitude: the direct detection rate of hypothetical weak-interacting dark matter particles through axial and/or vector elastic interactions with nuclei. | exploiting electron parity violation: from standard model tests to dark matter detection predictions |
we provide a parametric representation of nucleon form factors, uncertainties, and correlations at momentum transfers below a few gev2 incorporating all our knowledge about electromagnetic nucleon structure from electron scattering data and precise charge radii measurements as well as recent advances in radiative corrections and fit procedure. the proton magnetic form factor measurements of a1 collaboration are strikingly different to older data resulting in a 3-5 precise neutrino measurements and first measurements of the ground-state hyperfine splitting in muonic hydrogen call for further experimental investigations of the proton magnetic form factor at low momentum transfer <~ 1 - 3gev2 . | electromagnetic proton form factors for neutrino physics and atomic spectroscopy |
we address techniques to make the theoretical underpinning of neutrino-nucleon scattering more robust. we see this foundation as a necessary step to disentangle fundamental physics (such as neutrino oscillation parameters) from nuclear effects. we address a reanalysis of old experiments with elementary targets, model-independent parametrizations of nucleon form factors based on analyticity, and lattice qcd calculations of the form factors. speaker. | neutrino-nucleon interactions and lattice qcd |
neutrino nucleus elastic scattering (υael ) is a well understood standard model process. a generic scale of eυ <50 mev is usually taken to characterize the requirement of coherency in vael process. to quantify this transition, we formulated a universal parametrization of the degree of coherency. the texono experiment is pursuing measurement of the υael interactions with the reactor neutrinos at kuo-sheng reactor neutrino laboratory (ksnl), in a kinematic regime where the quantum mechanical coherency is complete. point-contact germanium detectors at sub-kev sensitivities are adopted to detect the low-energy nuclear recoils in υael . we report our latest status and plan of this program. a complementing line of research is on the formulation of a universal scheme to quantify the qm coherency effects in υael , and study their dependence on experimental configurations. constraints from existing measurements from coherent experiment are presented. | probing the neutrino-nucleus elastic scattering with point contact germanium detectors and its quantum-mechanical coherency effects |
minerva is a precision cross section experiment for neutrino scattering processes on various nuclei. charged-current quasi-elastic (ccqe) cross sections are relevant for neutrino oscillation experiments such as t2k, nova and dune. this talk describes how minerva's nuclear targets are used to measure the scaling in ccqe-like event rates as function of target nucleus. ccqe-like is defined as events with no detected pion. preliminary results are shown for rates of ccqe-like events produced in the minerva medium energy run on carbon, hydrocarbon, iron, and lead targets. the presented data are analyzed in terms of muon variables, proton variables and variables that combine information from muons and proton. | preliminary results in minerva's nuclear targets for ccqe-like events |
neutrino neutral-current elastic scattering is sensitive to the axial form factor of the proton and affords a unique method to access the strangeness contribution to the axial form factor gas(q2) and to the proton spin δs . the microboone experiment is an 85-ton active mass liquid argon time projection chamber located at the fermilab booster neutrino beamline. microboone is able to detect protons with kinetic energy as low as 50 mev. we present an inclusive differential cross section measurement of a signal with one proton and no other particles (nc1p) in the final state. we report the progress toward the measurement of exclusive neutral-current elastic scattering cross section and δs extraction using a subset of microboone's data. | studying neutral current elastic scattering and the strange axial form factor in microboone |
we propose to measure the γ-ray emission probability from excited states above 5 mev including giant resonance of 16o and 12c as a function of excitation energy in 1-mev step. here, we measure both the excitation energy (ex=5-30mev) at the forward scattering angles (0°-3°) of the 16o, 12c (p, p') reaction using grand-raiden spectrometer and the energy of γ-rays (eγ) using an array of nai(tl) counters. the purpose of the experiment is to provide the basic and important information not only for the γ-ray production from primary neutral-current neutrino-oxygen (-carbon) interactions but also for that from the secondary hadronic (neutron-oxygen and -carbon) interactions. | rcnp e398 16o,12c(p,p') experiment: measurement of the γ-ray emission probability from giant resonances in relation to 16o,12c(ν,ν') reactions |
current and future generation neutrino oscillation experiments aim towards a high-precision measurement of the oscillation parameters and that requires an unprecedented understanding of neutrino-nucleus scattering. charged-current quasi-elastic (ccqe) scattering is the process in which the neutrino produces a charged lepton and removes a single intact nucleon from the nucleus without producing any additional particles. for existing and forthcoming accelerator-based neutrino experiments, ccqe interactions are either the dominant process or part of the signal. microboone is the first liquid argon time projection chamber (lartpc) commissioned as part of the short baseline neutrino (sbn) program at fermilab and its excellent particle reconstruction capabilities allow the detection of neutrino interactions using exclusive final states, which will play a crucial role in the success of future kiloton lartpc detectors such as dune. this talk will present the first measurement on argon of exclusive νμ ccqe-like flux integrated total and differential cros sections using single proton knock-out interactions recorded by the microboone lartpc detector with 4 π acceptance and a 300 mev/c proton threshold. | first measurement of differential charged current quasielastic-like νμ-argon scattering cross sections with the microboone detector |
lux-zeplin (lz) is a direct detection dark matter experiment, currently under construction 4850ft underground at the sanford underground research facility in lead, sd, usa. at the core of the lz design is a dual-phase liquid xe time projection chamber (tpc) with a 7ton active mass. the lz tpc is optimized to detect low-energy depositions making it sensitive to the neutrino emission from core-collapse supernovae. these neutrinos, with o(10mev) kinetic energy, can interact via coherent elastic neutrino-nucleus scattering (ce νns) depositing o(1kev) in lz. this presentation gives an overview of the lz tpc, presents different cevns nuclear form factors and discusses the impact they have on lz's sensitivities to these signals. | impact of nuclear form factors on supernova neutrino detection in lz |
ship is a new general purpose fixed target facility, whose technical proposal has been recently reviewed by the cern sps committee and by the cern research board. the two boards recommended that the experiment proceeds further to a comprehensive design phase in the context of the new cern working group ”physics beyond colliders”, aiming at presenting a cern strategy for the european strategy meeting of 2019. in its initial phase, the 400 gev proton beam extracted from the sps will be dumped on a heavy target with the aim of integrating 2 × 1020 pot in 5 years. a dedicated detector, based on a long vacuum tank followed by a spectrometer and particle identification detectors, will allow probing a variety of models with light long-lived exotic particles and masses below o(10) gev/c2. the main focus will be the physics of the so-called hidden portals, i.e. search for dark photons, light scalars and pseudo-scalars, and heavy neutrinos. the sensitivity to heavy neutrinos will allow for the first time to probe, in the mass range between the kaon and the charm meson mass, a coupling range for which baryogenesis and active neutrino masses could also be explained. another dedicated detector will allow the study of neutrino cross-sections and angular distributions. ντ deep inelastic scattering cross sections will be measured with a statistics 1000 times larger than currently available, with the extraction of the f 4 and f 5 structure functions, never measured so far and allow for new tests of lepton non-universality with sensitivity to bsm physics. | status and physics of the ship experiment at cern |
we present a comparison of two microscopic models for pion production off nucleons by neutrinos and electrons, paying a special attention to the pion angular distribution in the final pion-nucleon center of mass system. both models predict clear anisotropic distributions in contrast to the ones assumed in some monte carlo generators used in neutrino experiment analyses. in the weak production case, parity violation is clearly seen in some channels as a lack of reflection symmetry with respect to the scattering plane. parity violation originates from the interference of multipoles with different phases in the hadronic current. for pion electroproduction, a comparison with experimental data shows the relevance of having a unitary model to reproduce some of the observables. | pion angular distributions in pion production off nucleons induced by neutrinos and electrons |
quantum chromodynamics (qcd) is the correct theory of strong interactions. the main direction of investigations in physics of elementary particles and nuclear physics is testing of qcd. qcd predicts that at high energy density there will be a transformation from ordinary nuclear matter to a plasma of free quarks and gluons, the quark-gluon plasma (qgp). in order to reach new knowledge of qcd from the interaction of relativistic heavy ions, one needs directly comparable data sets from systems of various sizes, different energies and different experimental probes. lepton-nucleus scattering provides a nontrivial possibility to study space-time evolution of jets inside the nuclear matter. using qcd-inspired time dependent cross sections for pre-hadrons we have introduced a space-time model for propagation and hadronization of quark and gluon jets in the nuclear matter in dis. the aim of this work is to examine a multiproduction process of charged-current deep inelastic vμ-nucleus and nuclear emulsion scattering and estimate quantitatively the value of the formation time. these studies may help to explain the jet quenching in heavy ion collisions. in conclusion, the role of neutrino generators in modern neutrino experiments with nuclear targets will be discussed. | monte carlo model for neutrino-nucleus interactions: past, present and future |
in recent years, much effort has been made to better understand the low energy nuclear recoil (nr) response in liquid xenon (lxe), allowing experiments to be increasingly sensitive to light dark matter. we propose a technique for ultra-low energy nr calibration using the recoils imparted to xenon nuclei during the de-excitation process following thermal neutron capture, where the instantaneous gamma cascade leaves the nuclei with less than 0.3 kev of recoil energy. a successful measurement of the quanta yields below this point will contribute to a greater sensitivity for lxe experiments that will benefit from a lower energy threshold, mainly those searching for light dark matter and coherent neutrino-nucleus scattering. we describe the calibration technique, including simulation and signal optimization, and its feasibility for a small lxe detector using a pulsed neutron source. | a proposal for an ultra-low energy nuclear-recoil calibration in liquid xenon using neutron capture |
understanding how particles behave in detectors is a critical part of analyzing data from neutrino experiments, but neutral particles are difficult to characterize. the purpose of this project was to calibrate the neutron response in quasielastic antineutrino scattering (qe) events in the minerva detector. we applied quasi-elastic assumptions to estimate the outgoing neutron kinematics in qe scattering, and then added modifications to improve the model's predictions for neutron response in data. we compared these kinematic predictions of neutron energy and angle to monte carlo simulations of qe scattering and to the behavior of reconstructed energy ``blobs'' that characterize neutral particle behavior in simulated and real minerva data. filtering events for neutron energy, angle, and distance from the interaction vertex, we derive calibration functions for both the simulation and real data. future work will include potential changes to the blobbing algorithms and refinement of the calibration technique using rigorous statistical methods. | data driven study of neutron response using quasielastic neutrino scattering in the minerva experiment |
the pico 500 dark matter detector at snolab will be be filled with about one tonne of superheated <strong> c_3f_8 </strong> freon operating at a recoil threshold below 3kev. the new experiment will extend the reach for spin dependent interactions with a planned start of operation in 2019 at snolab. the poster will provide an update on the status of the pico 500 experiment and the dark matter sensitivity for spin dependent dark matter. the large amount of active mass will allow pico to detect supernovae from coherent neutrino scattering on fluorine at a distance of up to 10kpc. we have studied the expected event timing sequence to verify and potentially optimize the probability of pico 500 detecting a significant signal. | supernova neutrino sensitivity and physics reach of the pico 500 experiment |
the large flux of mev neutrinos that nuclear reactors generate offer an excellent opportunity to study coherent elastic neutrino-nucleus scattering (ceνns), but reactors also produce significant backgrounds. the scintillating bubble chamber (sbc) collaboration is currently constructing a 10-kg liquid argon scintillating bubble chamber at fermilab. the detector's target threshold is 100 ev in order to demonstrate sensitivities to sub-kev nuclear recoils while remaining highly insensitive to electron recoil backgrounds. this talk presents a physics reach analysis of such a detector for reactor ceνns experiments. specifically, for studying the sensitivities to the weak mixing angle, neutrino magnetic moment, and a light z gauge boson mediator. monte carlo simulations assess the background's contribution to the signal, and silicon photomultipliers (sipm) can measure scintillation light to maximize background rejection. nearly mono-energetic photoneutron sources can calibrate the detector for nuclear recoils below 8 kev and gamma sources can use thomson scattering to probe the nucleation efficiency function near the target threshold. scintillating bubble chamber. | reactor ceνns physics reach with an sbc liquid argon bubble chamber |
a technique has been recently proposed to address the main limitations of past neutrino scattering experiments. in particular, it allows precise measurements of high statistics samples of (anti)neutrino-hydrogen interactions and of various nuclear targets. the planned high intensity lbnf beams give access to a broad mixture of measurements of electroweak parameters, qcd and hadron structure of nucleons and nuclei, nuclear physics, form factors, structure functions and cross-sections, as well as searches for new physics or verification of existing outstanding inconsistencies. | precision (anti)neutrino scattering off nucleons and nuclei |
the coherent experiment is designed to measure neutrino scattering at tens of mev on various nuclear targets. coherent is the first experiment that has successfully measured the coherent elastic neutrino-nucleus scattering interaction in multiple detectors using neutrinos produced by the spallation neutron source at oak ridge national laboratory. however, neutron signals are a background for the coherent detectors. to address this, there is a dedicated neutron monitoring system: the multiplicity and recoil spectrometer (mars). this work describes an effort to model the cf-252 neutron source as a calibration source using a geant4 simulation. the simulation generates neutron and gamma energy deposit data for the mars neutron-monitoring detector to compare to previously collected calibration data to model the mars detector's response. undergraduate student researcher. | simulating the mars detector response to a cf-252 source |
it has been shown that a class of matrix elements of two spatially-separated currents, which are computable directly in lattice qcd, can be factorized into parton distribution functions with calculable hard coefficients; in the same manner as the parton distribution functions are extracted from the hadronic cross sections measured in an experiment. we will discuss this most generalized method to obtain parton distribution functions from a lattice qcd calculation. we also discuss the direct lattice qcd calculation of hadronic tensor which can shed light on the understanding of parton physics in the deep inelastic scattering (dis) region and neutrino-nucleus scatterings in the shallow inelastic scattering (sis) region. in this talk, we will briefly introduce the framework of calculating hadronic tensor on the lattice and present some preliminary results. this work is supported by the u.s. department of energy, office of science, office of nuclear physics under contract de-ac05-06or23177. we acknowledge the facilities of the usqcd collaboration used for this research in part, which are funded by the office of science of the u.s. department of energy. | hadron structure from current-current correlation functions in lattice qcd |
high-precision measurements of neutrino oscillation parameters require a deep understanding of neutrino interactions with the atomic nuclei of detectors. these nuclear effects are one of the main sources of systematic uncertainty in neutrino experiments. to help resolve this, we take advantage of electron-deuteron scattering data using the large-acceptance clas detector at jefferson lab. this data could be particularly useful in this process, because such a light and simple nucleus is relatively well-understood. the elimination of tangled nuclear effects is also an attractive reason to consider deuterium-based detectors. i will present our results on the benchmarking of neutrino energy reconstruction methods using 5-gev electron-deuteron scattering data. for the clas collaboration. | benchmarking of neutrino energy reconstruction methods using electron-deuterium scattering data |
extracting neutrino oscillation parameters from experiments such as dune relies on determining the incident neutrino energy for each event individually. we exploited the similarities between electron- and neutrino-nucleus scattering to test energy reconstruction techniques using electron data with a known beam energy from the clas detector at the thomas jefferson national accelerator facility. previous work done for the clas collaboration by the electrons for neutrinos (e 4 ν) collaboration focused on the more easily understood quasielastic events with one proton and zero pions. we extended this analysis to 1 p 1 π events, which are dominated by resonance production. only a fraction of the pπ- events reconstructed to the correct beam energy and none of the pπ+ events did. we will present data on the incident energy and target mass dependence of the energy reconstruction, as well as comparisons to simulations using the genie neutrino event generator. | electrons for neutrinos: lepton energy reconstruction in the resonance excitation region |
ship (search for hidden particles) is a proposed beam dump experiment at cern sps, with the aim of exploring the so-called hidden sector. since a large neutrino flux is expected to be produced at the beam dump, the experiment could also allow for the study of neutrino physics with unprecedented statistics. a dedicated scattering and neutrino detector (snd), equipped with a downstream muon identification system, is thus being designed. the snd muon detector consists of iron filters interleaved with tracking planes, based on rpc technology. each muon plane has an active area of about (2 x 4) m2 and consists of three large gaps read out by two panels of perpendicular strips. the ship rpcs have to provide a uniform spatial response as well as high efficiency. the design of the snd muon system is presented and the performance of a ship rpc prototype is discussed. | rpcs for the snd muon system of the ship experiment |
the properties of the propagation of scintillations light in the liquid argon, at λ=128 nm wavelength, has been experimentally investigated in a dedicated setup at cern. the velocity of scintillation photons has been measured for the first time in the liquid argon. the obtained result, 1/vg = 7.5 ± 0.1 ns/m, is then used to derive the refractive index and the rayleigh scattering of the liquid argon at vuv region. such measurement provides a key ingredient for the interpretation of data from the current and next generation large mass liquid argon detectors as those dedicated to the search for rare events such as neutrinos or dark matter. furthermore the improvement on the understanding of the scintillation light propagation represent a benchmark for the multiple theoretical models and simulations for the next generation of detectors. | propagation of scintillation light in liquid argon |
nova is a long-baseline accelerator neutrino experiment primarily designed to measure neutrino oscillations. a high purity muon neutrino beam is produced at fermilab with a central energy of approximately 1.8 gev. nova consists of a near detector located 1 km downstream of the beam target at fermilab and a far detector located 810 km away in ash river, minnesota. the large uncertainty in the absolute neutrino flux affects cross-section measurements in the near detector. since the cross-section of the neutrino-electron elastic scattering can be accurately calculated, it provides an in situ constraint on the absolute flux. we present the status of the measurement of the neutrino-electron elastic scattering rate using a convolutional neural network (cnn) to identify signal events in an inclusive dataset. | status of the measurement of neutrino-electron elastic scattering in the nova near detector |
short-range nucleon-nucleon correlations (srcs) are states in which the wavefunctions of two or more nucleons overlap for a short period of time. this period of strong overlap causes the correlated pair of nucleons to form a quasi-deuteron whose internal relative momentum is larger than the fermi-momentum. when a correlated pair interacts with a leptonic probe, the two correlated nucleons are ejected from the nucleus with a definite momentum and angle with respect to each other. although srcs have been studied in great detail in electron-scattering experiments, their contributions to neutrino cross-section measurements are not well understood. using the microboone detector, a liquid-argon time projection chamber located along the booster neutrino beamline («eν 0.8 gev ») at fermi national accelerator laboratory, we have developed an exclusive charged-current selection with 1 muon and 2 protons to compare with predictions from new nuclear models that contain the addition of src effects. we present here the status of this work. this work is supported by the us department of energy, office of science, medium energy nuclear physics program. | studying short-range nucleon-nucleon correlations in ar40 with microboone |
though several measurements of the sodium quenching factor in thallium-doped sodium iodide (nai(tl)) detectors exist, results from current measurements are in disagreement below about 30 kevnr. this discrepancy directly impacts the interpretation of results from nai(tl)-based wimp direct detection and coherent neutrino-nucleus elastic scattering searches. it has been suggested that this disagreement, rather than reflecting a true variation of the quenching factor across different nai(tl) detectors, is due to unaccounted for systematic errors in previous measurements. in particular, it has been suggested that previous experiments have overestimated the quenching factor at low energies due to an imperfect knowledge of the trigger efficiency of the nai(tl) detector setups. to reconcile the tension between measurements, we have performed an experiment to measure this quenching factor in five separate nai(tl) detectors in the same experimental setup. additionally, we have implemented a ''threshold-free'' triggering scheme to remove possible bias arising from trigger inefficiency of the nai(tl) detector. in this talk, we will present the results of our experiment and a comparison with previous nai(tl) quenching factor measurements. this work is supported by the nsf under grant numbers phy-1457995 and dge-1256259, and yale university. the work is also supported by funding for the anais experiment, which is supported by the spanish ministerio de economía y competitividad and the european regional development fund (mineco-feder) under grant fpa2017-83133-p, and the spanish agencia estatal de investigación under grant pid2019-104374gb-i00. | measurement of the sodium quenching factor across multiple nai(tl) detectors |
hamamatsu r11410-20 pmts are used in the red-100 two-phase xenon emission detector built to search for the rare process of coherent elastic neutrino-nucleus scattering using intense artificial neutrino flux. we demonstrate how to adapt the pmts for their operation under strong illumination caused by electroluminescent signals from gamma and cosmogenic muon backgrounds which are significant at shallow depth experimental sites. the pmt linearity is demonstrated for signals in the dynamic range from 1 to 2*104 photoelectrons. impact of a photoelectric effect at the pmt first dynode to the capabilities of the red-100 photodetection system is studied and quantified. | performance of hamamatsu r11410-20 pmts under intense illumination in a two-phase cryogenic emission detector |
the snd@lhc detector experiment is located at the large hadron collider (lhc), about 480 m downstream of the atlas interaction point. the detector is designed to measure, for the first time ever, high-energy neutrinos produced at the lhc in the pseudorapidity region of 7.2<η<8.4, which is inaccessible to other lhc experiments. the detector comprises a hybrid system that incorporates multiple components. the detector includes a 830 kg target composed of tungsten plates arranged in alternating layers with nuclear emulsion and electronic trackers: this arrangement functions as an electromagnetic calorimeter. following the electromagnetic calorimeter, there is a hadronic calorimeter and a muon identification system. the detector possesses the ability to differentiate interactions involving all three neutrino flavours, enabling investigations into the physics of heavy flavour production in the forward region. this research is particularly significant for future circular colliders and high-energy astrophysical neutrino experiments. furthermore, the detector has the ability to search for the scattering of feebly interacting particles. the detector started operating during the lhc run 3, and it collected a total of ∼39 fb‑1 in 2022. the detector aims to collect approximately 250 fb‑1 in the whole of run 3. | snd@lhc: a new experiment in neutrino physics at the lhc |
the icecube collaboration has recently identified events due to ultrahigh-energy neutrino interactions. predictions of the neutrino-nucleon cross section at ultrahigh energies require a huge extrapolation of the cross sections experimentally measured at laboratory energies. upon relating neutrino scattering to deep inelastic electron scattering, we show that the empirically verified color dipole picture is well suited for such an extrapolation. the dominant contribution to the total neutrino-nucleon cross section, even at ultrahigh energies, is due to the kinematic range where color tranaparency is valid for the color dipole interaction. we deviate from various claims in the literature on the presence of screening effects due to non-linear evolution at ultrahigh neutrino energies. | problems with ultrahigh-energy neutrino interactions |
we investigate the phenomenology of a class of model that at the same time solves the tachyonic slepton problem of the pure anomaly mediated supersymmetry breaking (amsb) model and generates neutrino masses. we introduce heavy fields in the seesaw mechanism that are the messengers in the deflected amsb scenario. various theoretical and phenomenological constraints have been taken into account, especially the higgs mass limits. the viable parameter regions have been specified, and the properties of dark matter candidate have been studied. we point out that the type iii seesaw with three generations of 24-messenger is excluded, while the type ii seesaw and type iii seesaw with two generations of 24-messenger are still allowed. the sparticle masses are heavy as in usual susy models. the spin-independent crosssection of the scattering between the lightest neutralino and proton show the possibility to see evidences of new physics from future dark matter search experiments. we find that the lepton flavor violation effects caused by the yukawa mediation are suppressed due to the electroweak symmetry breaking condition. | seesaw-deflected anomaly mediation and the 125 gev higgs boson |
when studying neutrino oscillations an understanding of charged current quasielastic (ccqe) neutrino-nucleon scattering is imperative. this interaction depends on a nuclear model as well as knowledge of form factors. ccqe data from neutrino scattering off of carbon from the miniboone experiment is analyzed. like we use the z-expansion for the axial form factor, but instead of an rfg nuclear model, we use a correlated fermi gas nuclear model (cfg) to extract the axial radius. this project was supported through the wayne state university reu program under nsf grant phy-1460853. | determination of the axial radius in quasielastic neutrino-carbon scattering through z-expansion and the correlated fermi gas nuclear model |
next generation neutrino oscillation experiments are poised to answer key questions about the nature of the neutrino. the axial form factor is a vital ingredient in the nucleon amplitudes used to predict quasielastic scattering, the primary signal measurement process for dune, yet the form factor uncertainty is vastly underestimated by the dipole parameterization and a model independent parameterization is not well constrained by elementary target data. lattice qcd has the ability to make significant impact upon neutrino oscillation experiments by computing, from first principles, the interaction of a nucleon with a weak current in the absence of a nuclear medium. results from these lqcd calculations can significantly reduce the uncertainty for nucleon amplitudes and assign a robust, systematically-improvable error budget. recent calculations of the nucleon axial charge have demonstrated that sub-percent precision is possible on this vital quantity. in this talk, i will discuss preliminary results for the callat collaboration's calculation of the axial form factor of the nucleon and outline the path toward achieving a result with a complete error budget. results from lqcd will permit more complete factorization of uncertainties from nucleon and nuclear sources. | nucleon axial form factor for neutrino oscillation from lattice qcd |
minerνa is a neutrino-nucleus scattering experiment employing multiple nuclear targets. the experiment is studying neutral pion production due to coherent, resonant and deep-inelastic processes, from both charged current and neutral current reactions. neutral pions are detected through their two photon decay and the resultant electromagnetic showers. we will describe the analysis for the cross sections of inclusive and exclusive processes. | coherent and neutral pion production results from minerνa |
minerνa (main injector experiment for ν-a) is a dedicated neutrino-nucleus scattering experiment at fermilab. it uses a fine-grained fully active detector to make precision measurements of neutrino and antineutrino interactions on a variety of different nuclear targets (plastic scintillator, c, fe, pb, he and h2o) for energies up to few gev. an overview of the experiment and a description of the detector are presented. | the minerνa detector |
the coherent elastic neutrino-nucleus scattering (cenns) process is important to understand supernovae, nuclear form factors, and low-energy behavior of the standard model. it will also become more important as a background in direct-detection dark matter experiments. the process has yet to be observed because of the low-energy detection thresholds and neutron background reduction required. recent advances in cryogenic detector technology now make it possible. the cenns collaboration proposes to deploy a 1-ton-scale, single-phase, liquid argon scintillation detector near the fermilab booster neutrino beam (bnb) for a first measurement. a detector near the neutrino production target at 90 degrees off-axis will observe a low-energy flux of 10-50 mev stopped-pion neutrinos for cenns. the details of this effort including prototype detectors and neutron background measurements will be presented. | coherent elastic neutrino nucleus scattering (cenns) experiment at the fermilab booster neutrino beam |
one of the challenges in quantum many-body physics is calculating the electroweak response of a nucleus by fully accounting for the dynamics of its constituent nucleons. electron-scattering experiments have been pivotal to expose the role of nuclear correlations and in particular their spin-isospin dependence in the initial target state. besides, accurate calculations of lepton-nucleus scattering are of paramount importance to the accelerator-neutrino experimental program. greens function monte carlo (gfmc), using as inputs realistic hamiltonian and consistent electroweak currents, enables first-principles calculations of nuclear electroweak responses in the quasi-elastic region. i will present our gfmc results for electron and neutrino scattering on 12c, induced by electromagnetic-, neutral-, and charged-current transitions. i will argue how the strength and energy-dependence of two-nucleon processes associated with correlation effects and interaction currents are crucial in providing the most accurate description of lepton-nucleus scattering in the quasi-elastic regime. office of science, office of nuclear physics, under contract de-ac02-06ch11357. | inclusive lepton-nucleus scattering from quantum monte carlo |
the interpretation of results from current and future neutrino oscillation experiments will necessitate precision descriptions of neutrino-nucleus interactions. the achievement of this goal requires a multidisciplinary effort, with nuclear physics providing input to properly constrain leading systematics. collaboration between the electron and neutrino scattering communities has been developing to address this need. beyond oscillation experiments, differences between electron and neutrino experiments can provide insight into nucleon and nuclear structure. this talk will highlight some recent and anticipated results from electron scattering experiments of direct relevance to neutrino data, as well as discuss some synergistic studies of interest to both communities. | what can electron scattering tell us about neutrino physics? |
the extraction of neutrino mixing parameters from neutrino oscillation experiments relies on the reconstruction of the incident neutrino energy and knowledge of the neutrino-nuclei interaction cross-section. charged current quasi elastic (ccqe) scattering, in which the incoming neutrino knocks out a nucleon and leaves the rest of the nucleus intact, is the simplest inelastic interaction process. the incoming energy reconstruction for this type of process is also considered relatively simple. thus it is chosen by many accelerator based neutrino experiments as their signal or a dominant portion of it. microboone is the first liquid argon time projection chamber (lartpc) commissioned at fermilab. its excellent particle reconstruction capabilities allow the detection of neutrino interactions using exclusive final states, which will play a crucial role in the success of future kiloton lartpc detectors such as dune. this talk will present the recently published, first measurement of exclusive νµ ccqe-like flux integrated total and differential cross sections using single proton knock-out interactions recorded by the microboone lartpc detector with 4pi acceptance and a 300 mev/c proton threshold. the measurement is compared to several event generators and challenges their prediction in specific parts of the phase space | first measurement of differential charged current quasielastic-like νµ-argon scattering cross sections with the microboone detector |
amplitudes derived from scattering data on elementary targets are basic inputs to neutrino-nucleus cross section predictions. a prominent example is the isovector axial nucleon form factor, fa(q2) , which controls charged current signal processes at accelerator-based neutrino oscillation experiments. previous extractions of fa from neutrino-deuteron scattering data rely on a dipole shape assumption that introduces an unquantified error. a new analysis of world data for neutrino-deuteron scattering is performed using a model-independent, and systematically improvable, representation of fa. a complete error budget for the nucleon isovector axial radius leads to ra2 = 0 . 46(22) fm2 , with a much larger uncertainty than determined in the original analyses. the quasielastic neutrino-neutron cross section is determined as σ(νμ n ->μ- p) |eν = 1gev = 10 . 1(0 . 9) ×10-39cm2 . the propagation of nucleon-level constraints and uncertainties to nuclear cross sections is illustrated using minerva data and the genie event generator. these techniques can be readily extended to other amplitudes and processes. | deuterium target data for precision neutrino-nucleus cross sections |
neutrino oscillations are an active area of research, with experiments such as dune (deep underground neutrino experiment). dune will make use of large liquid argon detectors to perform a precision measurement of the cp violating phase. hence, an understanding of the argon nuclear ground state and its response to (anti-)neutrino interactions is of paramount importance. information about the nuclear ground state is encapsulated in the spectral function, s (k , e) , the joint probability of removing a nucleon of momentum k = |k | from the ground state leaving the residual (a-1) system with excitation energy e. e12-14-012 at jefferson lab ran in early 2017 and has measured the argon spectral function through coincidence (e ,e' p) scattering on 40ar and 48ti. the results of e12-14-012 are important to both the neutrino and nuclear physics communities. a direct measurement of the coincidence (e ,e' p) cross section from 40ar and 48ti will provide valuable information about the argon nucleus, as well as the experimental input necessary to constrain theoretical models used to calculate s (k , e) , paving the way for reliable estimates of the neutrino cross sections. data from e12-14-012 is currently being analyzed at uva and va. tech. supported in part by the department of energy grant no: de-fg02-96er40950. | coincidence (e,e'p) scattering on 40ar and 48ti to aid precision neutrino oscillation experiments |
germanium detectors with point contact configuration is an exciting detector technology which provides sub-kev sensitivities as low as 100 evee with kg-scale detector mass. this detector technique offers a unique opportunity to realize experiments on dark matter, to enhance the sensitivity of electromagnetic properties of neutrino and coherent elastic scattering of neutrino nucleus with reactor neutrino source. the texono collaboration have been pursuing this research program at the kuo-sheng neutrino laboratory (ksnl) in taiwan. we will highlight our results on neutrino electromagnetic properties, search of sterile neutrinos, as well as studies towards observation of neutrino-nucleus coherent scattering. the detector r&d programs which allow us to experimentally probe this new energy window will be discussed. the efforts set the stage and complement the cdex dark matter experiment at the new china jinping underground laboratory (cjpl) in china. | studies of neutrino interactions at the kuo-sheng neutrino laboratory with sub-kev ge-detectors |
we report new results for the exclusive and quasi-free cross sections off neutrons bound in deuterium γ* n(p) --> pπ-(p) , which are presented over a wide final hadron angle range with a kinematic coverage of the invariant mass (w) up to 1 . 825gev and the virtual photon four-momentum squared (q2) from 0 . 4 to 1 . 0gev2 . the experimental data were collected with the clas detector in hall b at jefferson laboratory. the exclusive structure functions have been extracted and their legendre moments were obtained. the exclusive quasi-free process has been kinematically isolated as successfully demonstrated by the comparison of the spectator momentum distribution of the simulation with the missing momentum distribution of the data. accordingly final-state-interaction contributions could be separated from the extracted quasi-free cross sections off bound neutrons solely based on the analysis of the experimental data. these new results will serve as long-awaited input for phenomenological analyses to extract the q2 evolution of previously unavailable n -->n* electroexcitation amplitudes and to improve state-of-the-art models of neutrino scattering off nuclei by augmenting the already available results from free protons. | exclusive π- electroproduction off the neutron in deuterium in the resonance region |
a good knowledge of both inclusive and exclusive neutrino interaction cross sections is one of the key issues for a precise determination of the neutrino oscillation parameters in the t2k experiment. these studies are performed at the near detector (nd280). its central tracker part equipped with a water target is used, among others, to study the νμccπ° reaction. at the energies of the t2k neutrino beam its contribution to the total cross section is relatively large, so the reaction is a potential source of the background for the quasi-elastic νμcc reaction. two different production mechanisms contribute to νμccπ°: single pion resonance production and deep inelastic scattering (dis). in addition, final state interactions (fsi) have to be considered. thus, the analysis of the νμccπ° reaction aims also at a better tuning of the monte carlo (mc) models used to describe neutrino interactions in t2k. this paper describes selection criteria leading to the determination of the inclusive and exclusive cross sections for the π° production in the νμcc interactions. | νμ ccπ° reaction in the tracker of the nd280 detector in the t2k experiment |
the coherent collaboration has proposed to measure coherent, elastic neutrino-nucleus scattering (ce νns) cross sections on several nuclear targets using neutrinos produced at the spallation neutron source (sns) located at the oak ridge national laboratory. the largest background of concern arises from beam-induced, fast neutrons that can mimic a nuclear recoil signal event in the detector. multiple technologies of neutron detection have been employed at prospective experiment sites at the sns. analysis of these data have produced a consistent picture of the backgrounds expected for a ce νns measurement. these background studies show that at suitable locations, the fast neutrons of concern arrive mainly in the prompt 1.3 μs window and the neutrons in the delayed window are primarily of lower energies that are relatively easier to shield. | background neutron studies for coherent elastic neutrino-nucleus scattering measurements at the sns |
previously, i have studied the photon production in neutral current (nc) neutrino-nucleon (nucleus) scattering, and addressed its relevance to the miniboone anomaly. (miniboone is a short baseline neutrino oscillation experiment at fnal.) in this talk i will review this topic, and discuss its connection to parity violating electron-nucleon scattering. such electron scattering has been used in qweak experiment at jlab to measure precisely the proton weak charge. in addition, the nucleon-to-resonance excitations induced by both weak and electromagnetic currents play important roles in the nc photon production process. understanding all these excitations in a unified microscopic framework is challenging. i will mention our effort along this line, and emphasize the complementarity between neutrino and electron scattering measurements of these excitations and their importance to improve our knowledge of nucleon structure. i acknowledge support from the us department of energy under grant de-fg02-93er-40756 and from fermi national accelerator laboratory under intensity frontier fellowship. | neutrino-nucleon (nucleus) scattering for non-neutrino physics: the case of neutral current induced photon production |
recent anti-neutrino data taken by the t2k experiment is used to measure the ratio of the cross sections for charged current interactions of muon type neutrinos relative to anti-neutrinos. theoretical estimates for charged current quasi-elastic neutrino-quark scattering predict this ratio should be approximately 1/3. this measurement used the π0 detector (p0d) and a time projection chamber (tpc1) directly downstream at the nd-280 complex of the t2k experiment. neutrino interactions occurring in the p0d with an exiting muon whose momentum is measured by tpc1 were selected. using these events, the ratio was calculated, and relevant systematic uncertainties were evaluated. | anit-nu/nu cross section ratio using p0d+tpc1 events |
this paper presents a design for a horizontal, adjustable path-length attenuation and scattering measurement device that has successfully observed attenuation lengths in excess of 130m in deionized (di) water. absolute measurements of attenuation and scattering in water have proven challenging, and values reported in literature show high variance. this system bypasses limitations on prior designs by using an optical path which remains purely in the liquid medium. path-length adjustment is performed using a hydraulic system to move an optical element (sensor or retroreflector) within the 5m fluid-filled cell. scattering measurements are performed at multiple ports along the beam axis, where a system of adjustable polarizers and attenuators allows separation of rayleigh and mie scattering components. attenuation measurements have been performed with di water which show excellent agreement with past experimental results across the visible spectrum. scattering measurements in optically pure water are ongoing. subsequently, the system will be used to characterize the optical properties of water-based liquid scintillator, a medium under consideration as a fill for large scale neutrino detectors. | an apparatus for light attenuation and scattering measurements in highly transparent media |
the suite of detector targets as part of the coherent experimental program includes a ton-scale array of nai[tl] crystals designed to measure coherent elastic-neutrino scattering (cevns) interactions on sodium and to study charged-current neutrino interactions on iodine. the 7.7 kg nai[ti] crystals being used are repurposed detector modules and must be characterized for quality and suitability for the measurement of low-energy signals. one set of detector modules has been characterized at the university of washington. the second set of modules is being characterized at the triangle universities nuclear laboratory (tunl) on duke university campus. the third set of modules is being characterized at oak ridge national laboratory (ornl). totaling 320 characterized modules that will be using in the construction of a ton-scale array of nai[ti] crystals. the characterization procedure uses known gamma-ray sources and background lines for testing the crystal quality, analyzing the gain response, determining energy resolution, and comparing the crystal response in different regions along its length. qualifying crystals will be deployed to ''neutrino alley'' located at ornl spallation neutron source (sns) experimental site. national science foundation (nsf), department of energy, and oak ridge national lab (ornl). | characterization of na[ti] crystals for ton-scale detector array |
the study of vector boson scattering (vbs) in zzjj events produced in proton-proton collisions at 13 tev will be reported. data used in analysis were collected by the atlas experiment during run ii and correspond to a total integrated luminosity of 140 fb-1. final states with four-charged lepton (4l) or two-charged lepton plus two neutrinos from the zz decays produced in association with two forward/backward jets are used to extract the vbs zzjj signal. the inclusive vbs zzjj production cross section will be measured. the electroweak vbs zz signal strength will be extracted with the bdt based analysis. national science foundation china scholarship council. | study vbs zz production with the atlas experiment |
the coherent collaboration operates a multi-target suite of low-threshold neutrino detectors at the spallation neutron source (sns) at oak ridge national laboratory. these detectors are uniquely equipped to observe the dominant low-energy (eν tens of mev) interaction of coherent elastic neutrino-nucleus scattering (cevns). cevns is a neutral-current process whose only experimental signal is scintillation from nuclear recoils of mere tens of kev. one characteristic of the standard model cross section for cevns is its dependence on the number of neutrons squared. in order to probe this n2 scaling with the relatively light 23na nucleus, coherent will deploy a tonne-scale detector with scintillating nai[tl] crystals, a successor to the naive detector. we will present the progress on construction and 2022 deployment for the nai neutrino experiment tonne-scale (naivete). | deployment of coherent multi-tonne nai[tl] detector (naivete) |
for scintillation based detectors, improving intrinsic light yield and light collection effeciency can directly improve sensitivity used in searches for rare physics processes. in my experimentation, a light yield of 23 pe/kev was found with an undoped cesium iodide (csi) crystal coupled to two photomultiplier tubes (pmts) at 77 kelvin. this could lower the energy threshold for future dark matter and neutrino-nucleus scattering experiments that use csi. by employing two pmts and requiring a coincident trigger, the background dark count created by the operating pmts can become negligible. this work was supported by nsf phy-1506036. | measuring the light yield of pure cesium iodide using two photomultiplier tubes at 77 kelvin |
the first observation of coherent elastic neutrino-nucleus scattering (cevns) was made by the coherent collaboration at the oak ridge national laboratory (ornl) spallation neutron source (sns) in august 2017 with a 14.6 kg csi(na) detector. one of the physics goals of the coherent experiment is to test the n2 dependence of the cevns cross section predicted in the standard model by observing cevns in multiple low-threshold detectors. to that end, the 24 kg cenns-10 liquid argon detector was deployed at the low-background neutrino alley at the sns. an observation of cevns with cenns-10 would provide a low n measurement to begin to map out the cevns cross section. cenns-10 was deployed in december 2016 for an initial engineering run ending in may 2017 and subsequently upgraded for a production run beginning in july 2017. in this talk, i will present the latest results from a cevns search with the cenns-10 liquid argon detector. this work is supported by the doe office of science graduate student research (scgsr) fellowship and the nsf office of nuclear physics. | results of a cevns search with the cenns-10 liquid argon detector |
the nature of dark matter is one of the fundamental questions to be answered. direct dark matter searches are focussed on the development, construction, and operation of detectors looking for the scattering of weakly interactive massive particles (wimps) with target nuclei. the measurement of the direction of wimp-induced nuclear recoils is a challenging strategy to extend dark matter searches beyond the neutrino floor and provide an unambiguous signature of the detection of galactic dark matter. current directional experiments are based on the use of gas tpc whose sensitivity is strongly limited by the small achievable detector mass. newsdm is an innovative directional experiment proposal based on the use of a solid target made by newly developed nuclear emulsion films and read-out systems achieving a position accuracy of 10 nm. | directional detection of dark matter with a nuclear emulsion based detector |
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