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coherent elastic neutrino-nucleus scattering (cevns) opens new approaches for the search of new physics beyond the standard model. the nucleus experiment aims to use the intense antineutrino flux produced from nuclear reactor cores to perform measurements of the cevns cross-section via gram-scale ultra-low threshold cryogenic detectors. a common problem with low threshold detectors is the calibration, since most radioactive sources tend to saturate the dynamical range of the sensors. in this dissertation, a photon-statistic based optical calibration setup has been developed and tested using detectors from the bullkid r&d project. both the developed hardware setup and the relative control software allow to automatically perform a full calibration of an array of detectors. during the development of this work, the diana analysis framework, developed for the cuore experiment, has been compatibilized with the nucleus daq and a new automatic analysis protocol was developed using the data from the nucleus prototype runs. this protocol proved to be accurate at reproducing the results obtained via a model dependent study performed with an almost event by event inspection that was carried out in the early stages of nucleus. particular focus was given to the development of an event reconstruction procedure used to measure the energy of events that lie outside the linear response region of the detector. the last activity done for the nucleus experiment was to develop a python based toolkit for the study of the discovery potential of the experiment. this toolkit was originally developed in the early stages of nucleus by j.rothe and has been intensely upgraded during the work presented in this thesis, in order to deal with different types of statistical checks and procedures. | development of energy calibration and data analysis systems for the nucleus experiment |
we analyze all available experimental data on the νμ and ν¯μ total and differential cross sections of charged-current single pion production through the decay of intermediate nucleon and baryon resonances measured on hydrogen and deuterium targets in the accelerator experiments at anl, bnl, fnal, and cern. these data are used to determine the current "resonance" axial-vector mass of the nucleon and to fine tune the nonresonance noninterfering background contribution which described within the rein-sehgal approach. for this analysis, we revise the phenomenological model and the experimental dataset for the fits, modify the method of likelihood analysis compared to the previous study. the obtained model parameters coming in combination with a revised strategy for the normalization of the breit-wigner distributions are slightly different from the values used by default. | resonance axial-vector mass from experiments on neutrino-hydrogen and neutrino-deuterium scattering |
minerνa (main injector experiment for ν-a) is a neutrino scattering experiment in the numi high-intensity neutrino beam at the fermi national accelerator laboratory. minerva was designed to make precision measurements of low energy neutrino and antineutrino cross sections on a variety of different materials (plastic scintillator, c, fe, pb, he and h2o). we present the current status of the charged current quasi-elastic scattering in plastic scintillator. | charged current quasi-elastic neutrino analysis at minerνa |
abelian dark sector scenarios embedded into the two-higgs doublet model are scrutinized within the coherent elastic neutrino-nucleus scattering experiment, which was first measured by the coherent collaboration in 2017 with an ongoing effort to improve it since then and recently released data for the csi target in 2022. in the theoretical framework, it is assumed that there is a u (1 ) gauge group in the dark sector with a nonzero kinetic mixing with the hypercharge field. the coherent data for the targets csi and liquid argon are treated in both single and multibin bases to constrain the multidimensional parameter space, spanned by the dark gauge coupling, kinetic mixing parameter and the dark photon mass, of totally seven different representative scenarios which are also compared and contrasted among each other to find out about the most sensitive one to the data. the effect of refined quenching factor is also addressed. | constraining nonminimal dark sector scenarios with the coherent neutrino scattering data |
we show that the b-l supersymmetric standard model with inverse seesaw (blssmis) provides new dark matter (dm) candidates (lightest right-handed sneutrino and lightest b-l neutralino) with mass of order few hundreds gev, while most of other susy spectrum can be quite heavy, consistently with the current large hadron collider (lhc) constraints. we emphasize that the thermal relic abundance and direct detection experiments via relic neutralino scattering with nuclei impose stringent constraints on the b-l neutralinos. these constraints can be satisfied by few points in the parameter space where the b-l lightest neutralino is higgsino-like, which cannot explain the observed galactic center (gc) gamma-ray excess measured by fermi-lat. the lightest right-handed sneutrino dm is analysed. we show that for a wide region of parameter space the lightest right-handed sneutrino, with mass between 80 gev and 1.2 tev, can satisfy the limits of the relic abundance and the scattering cross section with nuclei. we also show that the lightest right-handed sneutrino with mass script o(100) gev can account for the observed gc gamma-ray results. | dark matter in b-l supersymmetric standard model with inverse seesaw |
the ricochet experiment seeks to measure coherent (neutral-current) elastic neutrino-nucleus scattering (ceνns) using dark-matter-style detectors with sub-kev thresholds placed near a neutrino source, such as the mit (research) reactor (mitr), which operates at 5.5 mw generating approximately 2.2 × 1018 ν/second in its core. currently, ricochet is characterizing the backgrounds at mitr, the main component of which comes in the form of neutrons emitted from the core simultaneous with the neutrino signal. to characterize this background, we wrapped bonner cylinders around a 32he thermal neutron detector, whose data was then unfolded via a markov chain monte carlo (mcmc) to produce a neutron energy spectrum across several orders of magnitude. we discuss the resulting spectrum and its implications for deploying ricochet at the mitr site as well as the feasibility of reducing this background level via the addition of polyethylene shielding around the detector setup. | unfolding neutron spectrum with markov chain monte carlo at mit research reactor with he-3 neutral current detectors |
we report on epps16 - the first analysis of nlo nuclear pdfs where lhc p-pb data (z, w, dijets) have been directly used as a constraint. in comparison to our previous fit eps09, also data from neutrino-nucleus deeply-inelastic scattering and pion-nucleus drell-yan process are now included. much of the theory framework has also been updated from eps09, including a consistent treatment of heavy quarks in deeply-inelastic scattering. however, the most notable change is that we no longer assume flavour-blind nuclear modifications for valence and sea quarks. this significantly reduces the theoretical bias. all the analysed data are well reproduced and the analysis thereby supports the validity of collinear factorization in high-energy collisions involving heavy nuclei. however, flavour by flavour, the uncertainties are still rather large. | the epps16 nuclear pdfs |
in this paper, we study charged-current deep-inelastic scattering of muon neutrinos off 56fe nuclei by using the hirai, kumano, and saito model. the lha parton distribution functions (pdfs) - ct10 are used to describe the partonic content of hadrons. modification of pdfs inside the nuclei is done by using epps16 parametrization at next-to-leading order. target mass correction has also been incorporated in the calculations. we calculate the structure functions [f2(x ,q2) and x f3(x ,q2) ] , the ratios [r2(x ,q2) =f256fe/f2nucleon and r3(x ,q2) =f356fe/f3nucleon] , and the differential cross sections of νμ deep-inelastic scattering off nucleons and 56fe nuclei. we compare the results obtained with measured experimental data. the present theoretical approach gives a good description of data. | charged-current deep-inelastic scattering of muon neutrinos (νμ) off 56fe |
we propose to include in the analysis of borexino single event energy spectrum the scattering of $^{40}$k geo-antineutrinos by scintillator electrons. the hydridic earth model predicts the concentration of potassium in modern earth from 1\% to 4\% of the earth mass. we calculated contribution of $^{40}$k geo-antineutrino interactions in single borexino events for these concentrations. this contribution is comparable to the contribution from the interaction of cno neutrinos. we discuss the reasons for using the hydridic earth model. | on the contribution of the $^{40}$k geo-antineutrino to single borexino events |
the strange quark contribution to proton's spin ($\delta s$) is a fundamental quantity that is poorly determined from current experiments. neutrino-proton elastic scattering (pes) is a promising channel to measure this quantity, and requires an intense source of low-energy neutrinos and a low-threshold detector with excellent resolution. in this paper, we propose that neutrinos from a galactic supernova and their interactions with protons in large-volume scintillation detectors can be utilized to determine $\delta s$. the spectra of all flavors of supernova neutrinos can be independently determined using a combination of dune and super-(hyper-)kamiokande. this allows us to predict pes event rates in juno and theia, and estimate $\delta s$ by comparing with detected events. we find that the projected sensitivity for a supernova at 1 kpc (10 kpc), is approximately $\pm 0.01$ ($\pm 0.15$). interestingly, the limits from a nearby supernova would be comparable to the results from lattice qcd, and better than polarized deep-inelastic scattering experiments. using supernova neutrinos provides a true $q^2\rightarrow 0$ measurement, and thus an axial-mass independent determination of $\delta s$. | using supernova neutrinos to probe strange spin of proton with juno and theia |
the neutrino-nucleus reactions are studied at energies from 0 to 3 gev, using the crisp program. to simulate these reactions, crisp uses the monte carlo method through an intranuclear cascade model. quasielastic, baryonic resonance formation, and deep inelastic scattering channels for the neutrino-nucleon interaction are considered. the total and differential particle emission cross sections were obtained, resulting in a good agreement with the values reported by the miniboone experiment. the influence of nuclear effects on the studied reactions, such as fermionic motion and the pauli blocking mechanism, was shown. by using only neutrino-nucleon interactions (1p1h), it was necessary to modify the axial mass of the quasielastic channels to ma=1.35 gev (much higher than the value obtained in neutrino-deuterium reactions, ma=1.026 gev ). the problem in adjusting ma is the need for known ma(a ), where a is the mass number, in case we want to study another target nucleus. the introduction of the 2p2h processes solves this and also reproduces the experimental data with ma=1.026 gev . to show this, we use the transverse enhancement model to implement the 2p2h dynamic in crisp, in such a way that it can be used with any target nucleus. | study of neutrino-nucleus reactions with crisp model (0 <eν<3 gev ) |
we investigate the effect of one loop quantum corrections on the elastic scattering of dark matter off the nucleon in a fermionic dark matter model. the model introduces two new singlet fermions and a singlet scalar. the fermions communicate with the sm particles through a higgs portal. it is found that some viable regions in the parameter space respecting the bounds from the observed relic density, the higgs invisible decay width, and direct detection experiment, will be shrunk significantly when one loop effects are taken into account. the regions already resided below the neutrino floor, partly may come into regions which are testable by the current or future direct detection experiments. in addition, some regions being viable at tree level, may be excluded when quantum corrections are included. | loop enhancement of direct detection cross section in a fermionic dark matter model |
the discovery of coherent neutrino-nucleus scattering in the coherent experiment opened a source of new information for fundamental investigations in the realms of neutrino and nuclear physics, as well as in the realms of searches for new physics beyond the standard model. owing to substantial momentum transfers, a feature peculiar to the kinematical region of this experiment is that the effect of coherence is mixed with a sizable incoherent contribution rather than being seen in a pure form. on one hand, this leads to additional systematic uncertainties in studying the neutrino component of the coherence effect as such. on the other hand, this makes it possible to study a dynamical transition between the coherent and incoherent scattering modes and, in principle, to separate them experimentally. in our opinion, a consistent measurement of the coherent and incoherent cross sections for (anti)neutrino scattering on a nucleus in the same experiment seems a unique possibility, and its implementation would of course provide new data for neutrino physics, as well as for nuclear and new physics. in the present study, it is shown that this possibility is implementable not only in experiments that explore coherent neutrino and antineutrino scattering on various nuclei at accelerators, where the neutrino energy reaches several hundred mev units but also in reactor experiments, where antineutrino energies do not exceed 10 mev. the respective estimation is based on the approach that controls qualitatively a ``smooth transition'' of the cross section for (anti)neutrino-nucleus scattering from a coherent (or elastic) to an incoherent (inelastic) mode. in the former case, the target nucleus remains in the initial quantum state, while, in the latter case, its quantum state changes. observation of a specific number of photons that have rather high energies and which remove the excitation of the nucleus after its inelastic interaction with (anti)neutrinos is proposed to be used as a signal from such an inelastic process. an upper limit on the number of such photons is obtained in this study. | on the possibility of separating coherent and incoherent (anti)neutrino scattering on nuclei |
non-standard interactions (nsi) of the neutrino sector is studied in the framework of coherent elastic neutrino-nucleus scattering (ceν ns). differential and total cross sections of the ceν ns process for several nuclei are presented for different scale of incoming neutrino energy. behavior of form factor in accordance with the criteria of coherency process is also shown as a function of momentum transfer. several benchmarks were implemented according to the proposed advancement of ceν ns experiments. using recently analyzed bound, we forecast that the nsi cross section spectrum is larger than the standard model (sm) ones and increased for heavier nuclei. prediction of the nsi bounds is also given in the parameter space of the new interaction strengths by utilizing the deviation of nsi and sm spectrum ratio. all possibilities of non-universal flavor conserving (fc) and flavor violating (fv) process are considered as neutrino interact with the quark constituent of nucleus. | study of non-standard neutrino interactions in future coherent elastic neutrino-nucleus scattering experiments |
core collapse supernova simulations can be sensitive to neutrino interactions near the neutrinosphere. this is the surface of last scattering. we model the neutrinosphere region as a warm unitary gas of neutrons. a unitary gas is a low density system of particles with large scattering lengths. we calculate modifications to neutrino scattering cross sections because of the universal spin and density correlations of a unitary gas. these correlations can be studied in laboratory cold atom experiments. we find significant reductions in cross sections, compared to free space interactions, even at relatively low densities. these reductions could reduce the delay time from core bounce to successful explosion in multidimensional supernova simulations. | neutrino scattering in supernovae and the universal spin correlations of a unitary gas |
the spallation neutron source (sns) is a pulsed source of neutrons and, as a byproduct of this operation, an intense source of neutrinos via stopped-pion decay. the coherent collaboration uses this source to investigate coherent elastic neutrino-nucleus scattering (cevns) with a suite of detectors. to enable precise cross-section measurements, we must address an estimated 10\% uncertainty in our flux calculation associated with the lack of data for $\pi^\pm$ production from 1 gev protons on an hg target. we present here our geant4 simulation of neutrino production at the sns and our plans to experimentally normalize this flux with the development of a 670 kg d$_2$o detector. using the precise cross section calculations for neutrino interactions on deuterium, we will dramatically reduce our flux uncertainty. | coherent plans for d$_2$o at the spallation neutron source |
a non-relativistic effective field theory (nreft) offers a bottom-up framework to classify dark matter (dm) - nucleon interactions relevant for scattering at direct detection experiments by organizing the interactions in powers of the momentum transfer q → and dm velocity v → . this approach generates a number of operators including p-odd and t-odd operators; these can only be generated from a relativistic theory with cp violating interactions. we consider the leading order p-odd, t-odd operators viz. o10, o11 and o12 and compare the constraints on these operators from leading direct detection searches and from the bound on the neutron edm (nedm). we perform our analysis using simplified models with charged mediators and compute the loop diagrams contributing to the nedm. we find that constraints on the dm scattering cross section from the bound on the nedm are several orders of magnitude stronger than the limits from direct searches, and even well below the neutrino floor for such nreft operators, for the entire sub-gev to tev dm mass range. we conclude that one may not need to consider these operators when analyzing data from present or future direct dark matter detection experiments. | neutron edm constrains direct dark matter detection prospects |
the roles of strange axial form factor and axial mass for both neutral-current and charged-current reactions are investigated in the quasi-elastic neutrino-nucleus scattering within a relativistic single-particle model. the calculation is performed for various target nuclei like 12c, 40ca, 56fe, and 208pb at the incident neutrino (antineutrino) energies of 1.0 and 2.0 gev. then we discuss the dependence of differential cross section on the role of axial mass and strange axial form factor with different target nuclei on both neutral-current and charged-current reactions. finally we compare our results with the miniboone, t2k, and miner ν a experimental data for the double-differential cross section and the scaled total cross section. | role of axial mass and strange axial form factor from various target nuclei in neutrino-nucleus scattering |
this thesis describes the experimental work that finally led to a successful measurement of coherent elastic neutrino-nucleus scattering—a process proposed forty-three years ago. the experiment was performed at the spallation neutron source facility, sited at oak ridge national laboratory, in tennessee. of all known particles, neutrinos distinguish themselves for being the hardest to detect, typically requiring large multi-ton devices for the job. the process measured here involves the difficult detection of very weak signals arising from nuclear recoils (tiny neutrino-induced "kicks" to atomic nuclei), but leads to a much larger probability of neutrino interaction when compared to all other known mechanisms. as a result of this, "neutrino technologies" using miniaturized detectors (the author's was handheld and weighed only 14 kg) become a possibility. a large community of researchers plans to continue studying this process, facilitating an exploration of fundamental neutrino properties that is presently beyond the sensitivity of other methods. | first observation of coherent elastic neutrino-nucleus scattering |
nonlinearity of the liquid scintillator energy response is a key to measuring the neutrino energy spectrum in reactor neutrino experiments such as daya bay and juno. we measured the nonlinearity of the linear alkyl benzene based liquid scintillator in the laboratory, which is used in daya bay and will be used in juno, via the compton scattering process. by tagging the scattered gamma from the liquid scintillator sample simultaneously at seven angles, the instability of the system was largely cancelled. the accurately measured nonlinearity will improve the precision of the θ13, δm2, and reactor neutrino spectrum measurements at daya bay. | measurement of the liquid scintillator nonlinear energy response to electron |
the concept of coherence in the scattering of neutrinos and antineutrinos off nuclei is discussed. motivated by the results of the coherent experiment, a new approach to coherence in these processes is proposed, which allows a unified description of the elastic (coherent) and inelastic (incoherent) contributions to the total cross section for neutrino and antineutrino scattering off nuclei at energies below 100 mev. experiments and physical problems for coherent scattering of (anti)neutrinos off nuclei are briefly discussed. the extended appendix covers the main points and conclusions of the proposed approach in pedagogical detail. | concept of coherence in neutrino and antineutrino scattering off nuclei |
multiple coulomb scattering (mcs) is a well-known phenomenon occurring when charged particles traverse materials. measurements of muons traversing low z materials made in the muscat experiment showed that theoretical models and simulation codes, such as geant4 (v7.0), over-estimated the scattering. the muon ionization cooling experiment (mice) measured the cooling of a muon beam traversing a liquid hydrogen or lithium hydride (lih) energy absorber as part of a programme to develop muon accelerator facilities, such as a neutrino factory or a muon collider. the energy loss and mcs that occur in the absorber material are competing effects that alter the performance of the cooling channel. therefore measurements of mcs are required in order to validate the simulations used to predict the cooling performance in future accelerator facilities. we report measurements made in the mice apparatus of mcs using a lih absorber and muons within the momentum range 160 to 245 mev /c . the measured rms scattering width is about 9% smaller than that predicted by the approximate formula proposed by the particle data group, but within the latter's stated uncertainty. data at 172, 200 and 240 mev /c are compared to the geant4 (v9.6) default scattering model. these measurements show agreement with this more recent geant4 (v9.6) version over the range of incident muon momenta. | multiple coulomb scattering of muons in lithium hydride |
the wimp-nucleon scattering cross section in a simple dark matter model and its constraints from the latest direct detection experiment are treated here at the loop level. we consider a scenario with an emerging vector dark matter field that interacts with the standard model quarks, via loop contributions that are sourced from a scalar mediator. the involved parameter space for the dark matter-mediator masses is constrained by the xenon1t limit and the neutrino floor. the current direct detection bounds are eluded by invoking the top partners in a composite higgs model, whose scale mass helps us in suppressing the wimp-nucleon cross section. | top partners tackling vector dark matter |
recent high-precision measurements of nuclear deep inelastic scattering at high x and moderate 6 < q$^2$ < 9gev$^2$ give a rare opportunity to reach the quark distributions in the {\it superfast} region, in which the momentum fraction of the nucleon carried by its constituent quark is larger than the total fraction of the nucleon at rest, x>1. we derive the leading-order qcd evolution equation for such quarks with the goal of relating the moderate-q$^2$ data to the two earlier measurements of superfast quark distributions at large 60 < q$^2$ < 200~gev$^2$. since the high-q$^2$ measurements gave strongly contradictory estimates of the nuclear effects that generate superfast quarks, relating them to the high-precision, moderate-q$^2$ data through qcd evolution allows us to clarify this longstanding issue. our calculations indicate that the moderate-q$^2$ data at $x\lesssim 1.05$ are in better agreement with the high-q$^2$ data measured in (anti)neutrino-nuclear reactions which require substantial high-momentum nuclear effects in the generation of superfast quarks. our prediction for the high-q$^2$ and x>1.1 region is somewhat in the middle of the neutrino-nuclear and muon-nuclear scattering data. | qcd evolution of superfast quarks |
recently hints of lepton flavor nonuniversality emerged in the babar and lhcb experiments. in this paper we propose tests of lepton universality in ντ scattering. to parametrize the new physics we adopt an effective lagrangian approach and consider the neutrino deep inelastic scattering processes ντ+n →τ +x and νμ+n →μ +x where we assume the largest new physics effects are in the τ sector. we also consider an explicit leptoquark model in our calculations. in order to make comparison with the standard model and also in order to cancel out the uncertainties of the parton distribution functions, we consider the ratio of total and differential cross sections of tau-neutrino to muon-neutrino scattering. we find new physics effects that can possibly be observed at the proposed search for hidden particles (ship) experiment at cern. | probing lepton nonuniversality in tau neutrino scattering |
icecube is a neutrino observatory at earth's south pole that uses glacial ice as detector medium. secondary particles from neutrino interactions produce cherenkov light, which is detected by an array of photo detectors deployed within the ice. in distinction from the glacial bulk ice, hole ice is the refrozen water in the drill holes around the detector modules, and is expected to have different optical properties than the bulk ice. aiming to improve detector precision, this study presents a new method to simulate the propagation of light through the hole ice, introducing several new calibration parameters. the validity of the method is supported by a series of statistical cross checks, and by comparison to measurement and simulation results from other calibration studies. evaluating calibration data indicates a strongly asymmetric shielding of the detector modules. a preliminary analysis suggests that this cannot be accounted for by the shadow of cables, but can be explained by hole ice with a suitable scattering length, size, and position relative to the detector modules. the hole-ice approximation, which is used in the standard simulation chain is found to disagree with all existing direct-propagation methods and should be recalculated with a new direct-simulation run. | the effect of hole ice on the propagation and detection of light in icecube |
we study the effects of density-dependent weak vector form factors on the inclusive neutral-current-neutrino (antineutrino)-nucleus scattering in the quasi-elastic region within the framework of a relativistic single-particle model. the density-dependent weak form factors are obtained from a quark-meson coupling model. the density-dependence effects are studied separately in protons and neutrons participating in the reactions, in each response cross section, and with regard to asymmetry. these density effects reduce the cross section at high densities and show different behavior with regard to asymmetry. furthermore we calculate flux-averaged differential cross sections and compare them with the experimental data. | effects of density-dependent weak form factors on neutral-current neutrino (antineutrino)-neucleus scattering in the quasi-elastic region |
to describe low-energy (anti)neutrino fluxes in modern coherent elastic neutrino-nucleus scattering experiments as well as high-energy fluxes in precision-frontier projects such as the enhanced neutrino beams from kaon tagging (enubet) and the neutrinos from stored muons (nustorm), we evaluate (anti)neutrino energy spectra from radiative muon (μ- →e-νbareνμ (γ) ,μ+ →e+νeνbarμ (γ)), pion πℓ2 (π- →μ-νbarμ (γ) ,π+ →μ+νμ (γ)), and kaon kℓ2 (k- →μ-νbarμ (γ) ,k+ →μ+νμ (γ)) decays. we compare detailed o (α) distributions to the well-known tree-level results, investigate electron-mass corrections and provide energy spectra in analytical form. radiative corrections introduce continuous and divergent spectral components near the endpoint, on top of the monochromatic tree-level meson-decay spectra, which can change the flux-averaged cross section at 6 ×10-5 level for the scattering on 40ar nucleus with (anti)neutrinos from the pion decay at rest. radiative effects modify the expected (anti)neutrino fluxes from the muon decay around the peak region by 3 - 4 permille, which is a precision goal for next-generation artificial neutrino sources. | radiative (anti)neutrino energy spectra from muon, pion, and kaon decays |
we report the first demonstration of a phonon-mediated silicon detector technology that provides a primary phonon measurement in a low-voltage region, and a simultaneous indirect measurement of the ionization signal through neganov-trofimov-luke amplification in a high voltage region, both in a monolithic crystal. we present characterization of charge and phonon transport between the two stages of the detector and the resulting background discrimination capability at low energies. this new detector technology has the potential to significantly enhance the sensitivity of dark matter and coherent neutrino scattering experiments beyond the capabilities of current technologies that have limited discrimination at low energies. | phonon-mediated high-voltage detector with background rejection for low-mass dark matter and reactor coherent neutrino scattering experiments |
a technique using layered wavelength shifting, scintillating and non-scintillating films is presented to achieve discrimination of surface α events from low-energy nuclear recoils in liquid argon detectors. a discrimination power greater than 108 , similar to the discrimination possible for electronic recoils in argon, can be achieved by adding a 50 μm layer of scintillator with a suitably slow decay time, approximately 300 ns or greater, to a wavelength-shifter coated surface. the technique would allow suppression of surface α events in a very large next-generation argon dark matter experiment (with hundreds of square meters of surface area) without the requirement for position reconstruction, thus allowing utilization of more of the instrumented mass in the dark matter search. the technique could also be used to suppress surface backgrounds in compact argon detectors of low-energy nuclear recoils, for example in measurements of coherent neutrino-nucleus scattering or for sensitive measurements of neutron fluxes. | technique for surface background rejection in liquid argon dark matter detectors using layered wavelength-shifting and scintillating thin films |
there is a proposal to search for a sterile neutrino in a few kev mass range by the "troitsk nu-mass" facility. in order to estimate sterile neutrino mixing one needs to make precision spectrum measurements well below the endpoint using the existing electrostatic spectrometer with a magnetic adiabatic collimation, or mac-e filter. the expected signature will be a kink in the electron energy spectrum in tritium beta-decay. in this paper we consider the systematic effect of electron backscattering on the detector used in the spectrometer. for this purpose we provide a set of monte-carlo simulation results of electron backscattering on a silicon detector with a thin golden window with realistic electric and magnetic fields in the spectrometer. we have found that the probability of such an effect reaches up to 20-30%. the scattered electron could be reflected backwards to the detector by electrostatic field or by magnetic mirror. there is also a few percent probability to escape from the spectrometer through its entrance. a time delay between the scattering on the detector and the return of the reflected electron can reach a couple of microseconds in the troitsk spectrometer. such estimations are critical for the planning upgrades of the detector and the registration electronics. all considered effects are relevant to any mac-e type spectrometer with solid detector. | the role of electron scattering from registration detector in the "troitsk nu-mass" mac-e type spectrometer |
in this paper, we indicate a possibility of utilizing the intense chromium source (∼ 370 pbq) in probing the neutrino nature in low energy neutrino experiments with the ultra-low threshold and background real-time borexino detector located near the source (∼ 8 m). we analyse the elastic scattering of electron neutrinos (dirac or majorana, respectively) on the unpolarised electrons in the relativistic neutrino limit. we assume that the incoming neutrino beam is the superposition of left-right chiral states produced by the chromium source. left chiral neutrinos may be detected by the standard v - a and non-standard scalar s_l, pseudoscalar p_l, tensor t_l interactions, while right chiral ones partake only in the exotic v + a and s_r, p_r, t_r interactions. our model-independent study is carried out for the flavour (current) neutrino eigenstates. we compute the expected event number for the standard v-a interaction of the left chiral neutrinos using the current experimental values of standard couplings and in the case of left-right chiral superposition. we show that the significant decrement in the event number due to the interference terms between the standard and exotic interactions for the majorana neutrinos may appear. we also demonstrate how the presence of the exotic couplings affects the energy spectrum of outgoing electrons, both for the dirac and majorana cases. the 90~% c.l. sensitivity contours in the planes of corresponding exotic couplings are found. the presence of interferences in the majorana case gives the stronger constraints than for the dirac neutrinos, even if the neutrino source is placed outside the detector. | probing neutrino nature at borexino detector with chromium neutrino source |
we present a detailed qcd analysis of nucleon structure functions $xf_3 (x, q^2)$, based on laplace transforms and jacobi polynomials approach. the analysis corresponds to the next-to-leading order and next-to-next-to-leading order approximation of perturbative qcd. the laplace transform technique, as an exact analytical solution, is used for the solution of nonsinglet dokshitzer-gribov-lipatov-altarelli-parisi evolution equations at low- and large-$x$ values. the extracted results are used as input to obtain the $x$ and q$^2$ evolution of $xf_3(x, q^2)$ structure functions using the jacobi polynomials approach. in our work, the values of the typical qcd scale $\lambda_{\overline{\rm ms}}^{(n_f)}$ and the strong coupling constant $\alpha_s(m_z^2)$ are determined for four quark flavors ($n_f=4$) as well. a careful estimation of the uncertainties shall be performed using the hessian method for the valence-quark distributions, originating from the experimental errors. we compare our valence-quark parton distribution functions sets with those of other collaborations; in particular with the {\tt bbg}, {\tt ct14}, {\tt mmht14} and {\tt nnpdf} sets, which are contemporary with the present analysis. the obtained results from the analysis are in good agreement with those from the literature. | qcd analysis of nucleon structure functions in deep-inelastic neutrino-nucleon scattering: laplace transform and jacobi polynomials approach |
in this paper, we propose a scotogenic extension of the standard model (sm) which can provide a scalar dark matter (dm) candidate in the new, theoretically previously unaddressed, intermediate region (200≤mdm≤550gev) and also generate light dirac neutrino masses. in this framework, the sm is extended by three gauge singlet fermions, two singlet scalar fields and one additional scalar doublet along with a continuous global symmetry u(1)b−l and discrete symmetries z2 and z4. these additional symmetries prevent the singlet fermions from obtaining majorana mass terms along with providing the stability to the dm candidate. it is known that in the case of the scalar singlet dm model, the only region which is not yet excluded is a narrow region close to the higgs resonance ms≃mh2 — others ruled out from different experimental and theoretical bounds. in the case of the inert doublet model, the mass region (∼60-80gev) and the high-mass region (heavier than 550gev) are allowed. this motivates us to explore a parameter range in the intermediate-mass region mw≤mdm≤550gev, which we do in a scotogenic extension of sm with a scalar doublet and scalar singlets. the dm in our model is a mixture of singlet and doublet scalars, in the freeze-out scenario. we constrain the allowed parameter space of the model using the planck bound on present dm relic abundance, neutrino mass and the latest bound on spin-independent dm-nucleon scattering cross-section from the xenon1t experiment. further, we constrain the dm parameters from the indirect detection bounds arising from the global analysis of the fermi-lat observations of dwarf spheroidal satellite (dsphs) galaxies, higgs invisible decay and electroweak precision test (ewpt) as well. we find that our model findings may provide a viable dm candidate satisfying all the constraints on dm parameters in the new, previously unexplored mass range (200≤mdm≤550gev). this new window for the dm candidate could be searched in future experiments along with an explanation of the dirac mass of neutrinos since so far there is no strong evidence in support of the majorana nature of neutrino mass. | a new viable mass region of dark matter and dirac neutrino mass generation in a scotogenic extension of sm |
two-phase cryogenic avalanche detectors (crads) with combined thgem/gapd-matrix multiplier have become an emerging technique in rare-event experiments such as those of coherent neutrino-nucleus scattering and dark matter search. in this work we continue to study the performance of the two-phase crad in ar with thgem/gapd-matrix charge/optical readout. the matrix was composed of a 3×3 array of gapds (geiger-mode apds), optically recording thgem-hole avalanches in the near infrared (nir). gain, time, amplitude and spatial resolution properties of the combined multiplier are described. | study of combined thgem/gapd-matrix multiplier in a two-phase cryogenic avalanche detector in ar |
in this paper, we study the cofactor 2 zero neutrino mass matrices with the fritzsch-type structure in charged lepton mass matrix (clmm). in the numerical analysis, we perform a scan over the parameter space of all the 15 possible patterns to get a large sample of viable scattering points. among the 15 possible patterns, three of them can accommodate the latest lepton mixing and neutrino mass data. we compare the predictions of the allowed patterns with their counterparts with diagonal clmm. in this case, the severe cosmology bound on the neutrino mass set a strong constraint on the parameter space, rendering two patterns only marginally allowed. the fritzsch-type clmm will have impact on the viable parameter space and give rise to different phenomenological predictions. each allowed pattern predicts the strong correlations between physical variables, which is essential for model selection and can be probed in future experiments. it is found that under the no-diagonal clmm, the cofactor zeros structure in neutrino mass matrix is unstable as the running of renormalization group (rg) from seesaw scale to the electroweak scale. a way out of the problem is to propose the flavor symmetry under the models with a tev seesaw scale. the inverse seesaw model and a loop-induced model are given as two examples. | neutrino mass matrices with two vanishing cofactors and fritzsch texture for charged lepton mass matrix |
a search for heavy resonances decaying to a pair of z bosons is performed using data collected with the cms detector at the lhc. events are selected by requiring two oppositely charged leptons (electrons or muons), consistent with the decay of a z boson, and large missing transverse momentum, which is interpreted as arising from the decay of a second z boson to two neutrinos. the analysis uses data from proton-proton collisions at a center-of-mass energy of 13 tev, corresponding to an integrated luminosity of 35.9 fb-1. the hypothesis of a spin-2 bulk graviton (x) decaying to a pair of z bosons is examined for 600 ≤ m x ≤ 2500 gev and upper limits at 95% confidence level are set on the product of the production cross section and branching fraction of x → zz ranging from 100 to 4 fb. for bulk graviton models characterized by a curvature scale parameter \tilde{k}=0.5 in the extra dimension, the region m x < 800 gev is excluded, providing the most stringent limit reported to date. variations of the model considering the possibility of a wide resonance produced exclusively via gluon-gluon fusion or q\overline{q} annihilation are also examined. | search for zz resonances in the 2 ℓ2 ν final state in proton-proton collisions at 13 tev |
the paper describes the matching of tracks in a nuclear emulsion detector interleaved with scintillating optical fiber (scifi) planes. this technology is planned to be used in the scattering and neutrino detector (snd) of the new experiment ship (search for hidden particles) being developed in cern. the experiment ship aimed on the search of very weakly interacting particles in the poorly studied region of the particle masses below 10 gev will be installed in a beam dump facility at the super proton synchrotron (sps). the snd detector is aimed to provide temporal and spatial analysis of the particle showers and isolated tracks to separate and reconstruct events in nuclear emulsion. snd design includes emulsion cloud chamber (ecc) and scifi tracker. motivation for using the combination of ecc and scifi is to obtain the "real-time" information for the prompt and high-accuracy event analysis. the algorithm presented in the article provides a track matching accuracy not less than 50 μm with an efficiency of (89±8)%. | high resolution track matching in a hybrid scifi-emulsion detector |
in this article, we study the coherent pion production in the neutrino-nucleus interaction in the resonance region using the formalism based on the partially conserved axial current (pcac) theorem which relates the neutrino-nucleus cross section to the pion-nucleus elastic cross section. the pion-nucleus elastic cross section is calculated using the glauber model in terms of pion-nucleon cross sections obtained by parametrizing the experimental data. we calculate the differential and integrated cross sections for charged current coherent pion production in neutrino-carbon scattering. the results of integrated cross-section calculations are compared with the measured data. predictions for the differential and integrated cross sections for coherent pion productions in neutrino-iron scattering using the above formalism are also made. | coherent pion production in neutrino-nucleus scattering |
elastic scattering between dark matter particles and a relativistic species such as photons or neutrinos leads to a transfer of energy from the latter due to their intrinsically different temperature scaling relations. in this work, we point out that this siphoning of energy from the radiation bath manifests as a change in the effective number of neutrinos neff, and compute the expected shift δ neff for dark matter-photon and dark matter-neutrino elastic scattering as a function of the dark matter mass mψ and scattering cross section σψ-x. for (mψ,σψ-x)-parameter regions already explored by nonlinear probes such as the lyman-α forest through collisional and/or free-streaming damping, we find shifts of |δ neff| simeq o(10-2), which may be within the reach of the proposed cmb-s4 experiment. for most of the as-yet-unexplored parameter space, however, we expect |δ neff| lesssim o(10-3). an ideal 21 cm tomography survey of the dark ages limited only by cosmic variance is potentially sensitive to |δ neff| simeq o(10-6), in which case dark matter masses up to mψ ~ 10 mev may be probed via their effect on neff. | trading kinetic energy: how late kinetic decoupling of dark matter changes neff |
we present a novel analysis method for the determination of the neutrino-nucleon deep inelastic scattering (dis) cross section in the tev - pev energy range utilizing neutrino absorption by the earth. we analyze five years of data collected with the complete icecube detector from may 2011 to may 2016. this analysis focuses on electromagnetic and hadronic showers (cascades) mainly induced by electron and tau neutrinos. the applied event selection features high background rejection (< 10% background contamination below 60 tev, background free above 60 tev) of atmospheric muons and high signal efficiency (~ 80%). the final neutrino sample consists of 4808 events, with 402 events above 10 tev reconstructed energy. an unfolding method was applied to enable the mapping from reconstructed cascade parameters such as energy and zenith to true neutrino variables. the analysis was performed assuming isotropic astrophysical neutrino flux, in seven energy bins, and in two zenith bins ("down-going" from the south-hemisphere and "up-going" from the north-hemisphere). the ratio of down-going to up-going events (which are absorbed by the earth at high energies) is sensitive to the neutrino-nucleon cross section but insensitive to the astrophysical neutrino flux uncertainties. | tev-pev neutrino-nucleon cross section measurement with 5 years of icecube data |
we have designed and tested a large-area (0.15 m2) neutron detector based on neutron capture on 6li. the neutron detector design has been optimized for the purpose of tagging the scattering angle of kev-scale neutrons. these neutron detectors would be employed to calibrate the low-energy (<100 ev) nuclear recoil in detectors for dark matter and coherent elastic neutrino nucleus scattering (ce νns). we describe the design, construction, and characterization of a prototype. the prototype is designed to have a tagging efficiency of ∼25% at the relevant o(kev) neutron energies, and with a mean capture time of ∼ 17 μs . the prototype was characterized using a 252cf neutron source and agreement with the simulation was observed within a few percent level. | a backing detector for order-kev neutrons |
at the katrin experiment, the electron antineutrino mass is inferred from the shape of the β-decay spectrum of tritium. important systematic effects in the windowless gaseous tritium source (wgts) of the experiment include the energy loss by electron scattering, and the extended starting potential. in the wgts, primary high-energy electrons from β-decay produce an extended secondary spectrum of electrons through various atomic and molecular processes including ionization, recombination, cluster formation and scattering. in addition to providing data essential to the simulation of energy loss processes, the electron spectrum also provides information important in the simulation of plasma processes. these simulations will then provide an insight on the starting potential. here, a monte carlo approach is used to model the electron spectrum in the source for a given magnetic and electric field configuration. the spectrum is evaluated at different positions within the wgts, which allows for a direct analysis of the spectrum close to the rear wall and detector end of the experiment. alongside electrons, also ions are tracked by the simulation, resulting in a full description of the currents in the source. | monte carlo simulations of the electron - gas interactions in the katrin experiment |
finding unequivocal evidence of dark matter interactions in a particle detector is a major goal of research in physics. liquid argon time projection chambers offer a path to probe weakly interacting massive particles scattering cross sections on nuclei down to the so-called neutrino floor, in a mass range from a few gev to hundreds of tev. based on the successful operation of the darkside-50 detector at lngs, a new and more sensitive experiment, darkside-20k, has been designed and is now under construction. a thorough understanding of the darkside-50 detector response and, therefore, of all types of events observed in the detector, is essential for the optimal design of the new experiment. in this article, we report on a specific set of events, namely, standard two-pulse scintillation-ionization signals with a third small amplitude pulse, occurring within the 440 μs data acquisition window of standard events. some of these events are due to the photoionization of the tpc cathode. we compare our results with those published by collaborations using liquid xenon time projection chambers, which observed a similar phenomenon, and, in particular, with a recent paper by the lux collaboration (d.s. akerib et al. phys.rev.d 102, 092004 (2020)) from the measured rate of these events, we estimate for the first time the quantum efficiency of the tetraphenyl butadiene deposited on the darkside-50 cathode at wavelengths of around 128 nm, in liquid argon. also, both experiments observe events likely related to the photoionization of impurities in the liquid. the probability of photoelectron emission per unit length turns out to be an order of magnitude lower in darkside-50 than in lux. | a study of events with photoelectric emission in the darkside-50 liquid argon time projection chamber |
coherent elastic neutrino-nucleus scattering (ce υns) has an important role in measuring neutrino properties and proving non-standard interactions. neutrino elastic-scattering observation with nai(tl) experiment (neon) aims to detect this ce υns in a nai(tl) crystal using reactor anti-electron neutrino at hanbit nuclear power plant. neon detector, which is installed 24 m distance away from the active reactor core, consists of a 15 kg nai(tl) in the radiation shielding structures including a 700 l liquid scintillator. data taking has started from december 2020, which includes 1-month reactor-off period. we report the current status of neon experiment in this talk. | status of neutrino elastic-scattering observation with nai(tl) experiment |
we propose a novel scheme for distinguishing between the dirac and majorana nature of neutrinos via interaction of a neutrino beam with microwave photons inside a cavity. we study the effective photon-photon polarization exchange induced by the photon-neutrino scattering. the quantum field theoretical studies of such effective picture are presented for both dirac and majorana neutrinos. our phenomenological analyses show that the difference between dirac and majorana neutrinos can manifest itself in scattering rate of the photons. to enhance the effect a cavity scheme is employed. an experimental setup based on microwave cavities is then designed and simulated by finite element method to measure the scattering rate. our results suggest that an experiment based on the current state-of-the-art technology will be able to probe the difference in about one year. however, it can be done in a few days by enhancing the neutrino beam flux or implementing with the near future equipments. therefore, our work provides the possibility %puts the grounds for solving the long lasting puzzle of dirac or majorana nature of neutrinos. | distinguishing dirac from majorana neutrinos in a microwave cavity |
the discovery of the higgs boson has fully confirmed the standard model of particles and fields. nevertheless, there are still fundamental phenomena, like the existence of dark matter and the baryon asymmetry of the universe, deserving an explanation that could come from the discovery of new particles. searches for new physics with accelerators are performed at the lhc, looking for high massive particles coupled to matter with ordinary strength. a new experiment at cern meant to search for very weakly coupled particles in the few gev mass domain has been recently proposed. the existence of such particles, foreseen in different theoretical models beyond the standard model, is largely unexplored. a beam dump facility using high intensity 400 gev protons is a copious source of such unknown particles in the gev mass range. the beam dump is also a copious source of neutrinos and in particular it is an ideal source of tau neutrinos, the less known particle in the standard model. the neutrino detector can also search for dark matter through its scattering off the electrons. we report the physics potential of the ship experiment. | the ship experiment at cern |
a new measurement of coherent elastic neutrino-nucleus scattering (cevns) on liquid argon (lar) has been recently reported by the coherent experiment. relying on the new data, we update the status of cevns-induced constraints by considering various physics applications, within and beyond the standard model. in particular, we explore the implications of the coherent-lar data for electroweak and nuclear physics as well as for interesting scenarios beyond the sm such as nsis and electromagnetic neutrino properties. we show that compared to the existing constraints derived from the first cevns measurement on csi, the new lar-dataset yields improved constraints in all cases. | probing exotic neutrino physics with cevns |
kinematic imbalance of the final-state particles in the plane transverse to the neutrino direction provides a sensitive probe of nuclear effects. in this contribution, we report the minerva measurement of the single-transverse kinematic imbalance in neutrino charged-current quasielastic-like events on ch targets. to improve the momentum measurements of the final-state particles, we develop a method to select elastically scattering contained (esc) protons and a general procedure to correct the transverse momentum scales. | probing nuclear effects using single-transverse kinematic imbalance with minerva |
algorithms for neutrino-matter coupling in core-collapse supernovae (ccsne) are investigated in the context of a spectral two-moment model, which is discretized in space with the discontinuous galerkin method, integrated in time with implicit-explicit (imex) methods, and implemented in the toolkit for high-order neutrino-radiation hydrodynamics (thornado). the model considers electron neutrinos and antineutrinos and tabulated opacities from bruenn (1985), which includes neutrino-electron scattering and pair processes. the nonlinear system arising from implicit time discretization of the equations governing neutrino-matter coupling is iterated to convergence using anderson-accelerated fixed-point methods, which avoid formation of jacobians and inversion of dense linear systems. numerical experiments show that, for a given tolerance, a nested iteration scheme which aims to reduce opacity evaluations can lower the computational cost. our initial port to gpus, using both openmp and openacc, shows an overall speedup of up to ∼ 100× when compared to results using a single cpu core. these results indicate that the algorithms implemented in thornado are well-suited to gpu acceleration. this manuscript has been authored by ut-battelle, llc under contract no. de-ac05-00or22725 with the u.s. department of energy. the united states government retains and the publisher, by accepting the article for publication, acknowledges that the united states government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for united states government purposes. the department of energy will provide public access to these results of federally sponsored research in accordance with the doe public access plan (http://energy.gov/downloads/doe-public-access-plan). | thornado-transport: anderson- and gpu-accelerated nonlinear solvers for neutrino-matter coupling |
motivated by the recent measurement of the neutron distribution radius of 208pb from the prex-2 data, i study the effects of the new g3(m) parameter set constrained by prex-2 data on the electron-neutrino scattering in dense matter using the extended relativistic mean-field (e-rmf) model. i employ the g3(m) parameter set to describe the nuclear matter. the obtained equation of state for the g3(m) parameter set has an excellent agreement with experimental data and the chiral effective field theory calculation with n3lo 3n forces. i analyze both the differential cross section of the electron-neutrino and electron-neutrino mean free path to observe their sensitivity to the g3(m) parameter set. one finds that the differential cross sections of electron-neutrinos for different baryon densities have higher values compared with those obtained for the tm1e and fsu garnet parameter sets. the higher cross section decreases the electron-neutrino mean free path. | implications of prex-2 data on the electron-neutrino opacity in dense matter |
the cross sections of elastic neutrino scattering on electrons and nuclei in the regime of low-energy transfer are known to be very sensitive to neutrino electromagnetic properties. in particular, the magnetic moment of the neutrino can be effectively searched using liquid or solid detectors with a very low energy threshold. we present the formalism that incorporates the neutrino magnetic moment contribution in the theoretical treatment of the low-energy elastic neutrino scattering on a condensed-matter target. the concept of the dynamic structure factor is employed to describe the collective effects in the target. the differential cross section for tritium antineutrino scattering on the superfluid 4he is calculated numerically. we find that the neutrino magnetic moment of the order of 10-11μbstrongly affects the cross section. our results can be used in the search of neutrino magnetic moments in future low-energy neutrino scattering experiments with liquid or solid targets. | neutrino magnetic moments in low-energy neutrino scattering on condensed matter systems |
snd@lhc is a compact experiment that will detect high energy neutrinos produced by heavy flavour quarks at the lhc in the pseudo-rapidity region 7.2 $< \eta <$ 8.6. it is an hybrid system, comprising nuclear emulsions and electronic detectors, that allows all three $\nu$ flavours to be distinguished, thus opening an unique opportunity to probe the physics of charm production in the very forward region. the first phase aims at operating the detector throughout lhc run 3 collecting a total of 150 fb$^{-1}$. the electronic subdetectors were assembled in the summer and recently operated in test beams. | the scattering and neutrino detector at the lhc |
we present a model to calculate heat signal shapes from low-temperature bolometer attached to a crystal. this model is based on the elementary acoustic wave theory at low temperature and has been developed using modern monte carlo techniques. physical processes in phonon propagation, such as transmission, scattering and reflection are considered. using our model, the calculated time dependence of signal agrees with real experimental data. this model has applications in low-temperature rare event particle detectors for dark matter and neutrinos. | a model on heat signal of crystal detector at low temperature |
we summarise here the main differences of three models of neutrino-induced coherent pion production, namely the rein-sehgal and berger-sehgal models based on the partially conserved axial current theorem and the alvarez-ruso \textit{et al.} model which is using a microscopic approach. their predictions in the event generators are compared against recent experimental measurements for a neutrino energy from 0.5 to 20 gev. | charged current coherent pion production in neutrino scattering |
we present a detailed study of charged-current quasielastic (anti)neutrino scattering cross sections on a 12c target obtained using a spectral function s (p, e) that gives a scaling function in accordance with the electron scattering data. the spectral function accounts for the nucleon-nucleon (nn) correlations, it has a realistic energy dependence and natural orbitals (no's) from the jastrow correlation method are used in its construction. the results are compared with those when nn correlations are not included, namely harmonic-oscillator single-particle wave functions are used instead of no's. a comparison of the results with recent experiments, as well as to results from the superscaling approach is done. the contribution of two-particle two-hole meson-exchange currents on neutrino-nucleus interactions is also considered within a fully relativistic fermi gas. the results show a good agreement with the experimental data over the whole range of neutrino energies. | charged-current quasielastic (anti)neutrino cross sections on 12c with realistic spectral functions including meson-exchange contributions |
the microboone experiment at the fermi national accelerator laboratory, an 89-ton active mass liquid argon time projection chamber, affords a unique opportunity to observe low-$q^2$ neutral-current neutrino-proton scattering events. neutral-current neutrino-proton scattering at $q^2 < 1$ gev$^2$ is dominated by the proton's axial form factor, which can be written as a combination of contributions from the up, down, and strange quarks: $g_a(q^2) = \frac{1}{2}[-g_a^u(q^2)+g_a^d(q^2)+g_a^s(q^2)]$. the contribution from up and down quarks has been established in past charged-current measurements. the contribution from strange quarks at low $q^2$ remains unmeasured; this is of great interest since the strange quark contribution to the proton spin can be determined from the low-$q^2$ behavior: $\delta s = g_a^s(q^2=0)$. microboone began operating in the booster neutrino beam in october 2015. i will present the status in observing isolated proton tracks in the microboone detector as a signature for neutral-current neutrino-proton events. the sensitivity of the microboone experiment for measuring the strange quark contribution to the proton spin will be discussed. | progress on neutrino-proton neutral-current scattering in microboone |
in this work, we study charged current quasi-elastic scattering (qes) of {\bar{ν }}μoff nucleon and nucleus using a formalism based on the llewellyn smith (ls) model. parameterizations by galster et al. are used for electric and magnetic sach´s form factors of the nucleons. we use the fermi gas model along with the pauli suppression condition to take into account the nuclear effects in the anti-neutrino-nucleus qes. we calculate {\bar{ν }}μ -p and {\bar{ν }}μ -{}12{{c}} charged current quasi-elastic scattering differential and total cross sections for different values of axial mass ma , and compare the results with data from the ggm, skat, bnl, nomad, minerνa and miniboone experiments. the present theoretical approach gives a good description of differential cross section data. the calculations with axial mass {m}a=0.979 and 1.05 gev are compatible with data from most of the experiments. supported by department of science and technology, new delhi, india | charged current quasi-elastic scattering of {\\bar{\\nu }}_{\\mu } off 12c |
nuclear and particle physics provides an introductory course on nuclear and particle physics for undergraduate and early-graduate students, which the author has taught for several years at the university of zurich. it contains fundamentals on both nuclear and particle physics, giving emphasis to the discovery and history of developments in the field, and is experimentally/phenomenologically oriented. it contains detailed derivations of formulae such as 2-3 body phase space, the weinberg-salam model, and neutrino scattering. originally published in german as kern- und teilchenphysik, several sections have been added to this new english version to cover modern topics, including updates on neutrinos, the higgs boson, the top quark and bottom quark physics. | nuclear and particle physics |
a supernova event in our own galaxy will result in a large number of neutrinos detected on earth within the time-frame of a few seconds. these neutrinos will have been produced thermally with, in principle, three distinct temperatures for the electron, anti-electron and remaining heavy flavours respectively. we revisit the possibility that new mev-mass particles $\chi$ are also produced thermally during the event, which scatter with the neutrinos and alter their temperatures. our main emphasis is on the detectability of this effect using the neutrino spectrum, given the large uncertainty on the temperature and density profiles of the stellar matter. by marginalising over the parameters of a simple analytic model for the stellar profile, we find that super kamiokande could place an upper limit on the scattering cross section at the level of $\sigma_{\chi \nu} \sim 10^{-40} \cdot (t / \mathrm{mev})^2$ cm$^2$ for 10 mev mass particles at 90% confidence. a direct-detection-like experiment would be less susceptible to systematic uncertainties in the neutrino production and mixing, but this would need a target mass around 100 tonnes in order to acquire enough statistics to compete with super kamiokande. | how well can new particles interacting with neutrinos be constrained after a galactic supernova? |
the coherent elastic neutrino-nucleus scattering (cevns) plays a crucial role at the final evolution of stars. the detection of it would be of importance in astroparticle physics. among all available neutrino sources, galactic supernovae give the highest neutrino flux in the mev range. among all liquid xenon dark matter experiments, xmass has the largest sensitive volume and light yield. the possibility to detect galactic supernova via the cevns-process on xenon nuclei in the current xmass detector was investigated. the total number of events integrated in about 18 seconds after the explosion of a supernova 10~kpc away from the earth was expected to be from 3.5 to 21.1, depending on the supernova model used to predict the neutrino flux, while the number of background events in the same time window was measured to be negligible. all lead to very high possibility to detect cevns experimentally for the first time utilizing the combination of galactic supernovae and the xmass detector. in case of a supernova explosion as close as betelgeuse, the total observable events can be more than ten thousand, making it possible to distinguish different supernova models by examining the evolution of neutrino event rate in xmass. | detectability of galactic supernova neutrinos coherently scattered on xenon nuclei in xmass |
finding unequivocal evidence of dark matter interactions in a particle detector is a major objective of physics research. liquid argon time projection chambers offer a path to probe weakly interacting massive particles scattering cross sections on nucleus down to the so-called neutrino floor, in a mass range from few gev's to hundredths of tev's. based on the successful operation of the darkside-50 detector at lngs, a new and more sensitive experiment, darkside-20k, has been designed and is now under construction. a thorough understanding of the darkside-50 detector response and, therefore, of all kind of observed events, is essential for an optimal design of the new experiment. in this paper, we report on a particular set of events, which were not used for dark matter searches. namely, standard two-pulse scintillation-ionization signals accompanied by a small amplitude third pulse, originating from single or few electrons, in a time window of less than a maximum drift time. we compare our findings to those of a recent paper of the lux collaboration (d.s.akerib et al. phys.rev.d 102, 092004). indeed, both experiments observe events related to photoionization of the cathode. from the measured rate of these events, we estimate for the first time the quantum efficiency of the tetraphenyl butadiene deposited on the darkside-50 cathode at wavelengths around 128 nm, in liquid argon. also, both experiments observe events likely related to photoionization of impurities in the liquid. the probability of photoelectron emission per unit length turns out to be one order of magnitude smaller in darkside-50 than in lux. this result, together with the much larger measured electron lifetime, coherently hints toward a lower concentration of contaminants in darkside-50 than in lux. | a study of events with photoelectric emission in the darkside-50 liquid argon time projection chamber |
the reaction mechanisms for neutrino interactions with an 40ar nucleus with the lbnf flux are calculated with the giessen-boltzmann-uehling-uhlenbeck (gibuu) transport-theoretical implementation of these interactions. quasielastic scattering, many-body effects, pion production and absorption and deep inelastic scattering are discussed; they all play a role at the lbnf energies and are experimentally entangled with each other. quasielastic scattering makes up for only about 1/3 of the total cross section whereas pion production channels make up about 2/3 of the total. this underlines the need for a consistent description of the neutrino-nucleus reaction that treats all channels on an equal, consistent footing. the results discussed here can also serve as useful guideposts for the intermediate neutrino program. | neutrino-nucleus interactions at the lbnf near detector |
gravitational wave detector technology provides high-precision measurement apparatuses that, if combined with a modulated particle source, have the potential to measure and constrain particle interactions in a novel way, by measuring the pressure caused by scattering particle beams off the mirror material. such a measurement does not rely on tagging a final state. this strategy has the potential to allow us to explore novel ways to constrain the presence of new interactions beyond the standard model of particle physics and provide additional constraints to poorly understood cross-sections in the non-perturbative regime of qcd and nuclear physics, which are limiting factors of dark matter and neutrino physics searches. beyond high-energy physics, if technically feasible, the proposed method to measure nucleon-nucleon interactions can lead to practical applications in material and medical sciences. | particle physics with gravitational wave detector technology |
status of search of coherent elastic neutrino-nucleus scattering (ceνns) for reactor neutrino flux at kuo-sheng nuclear laboratory is discussed. different detector candidates being used for ceνns detection across the globe while germanium detector with its well matured technology and sub-kev threshold, seem to open unseen experimental approach to ceνns is widely discussed. reactor neutrinos having energy below 10 mev are ideal source for the study of ceνns interaction. we studied about the possible ceνns signals with associated uncertainties and limit on percentage of channeled nuclei in germanium crystal is quoted. detection of flavourless ceνns interaction can play a key role to open the new window on understanding of some unknown processes of the nature. | status of the search of coherent neutrino nucleus elastic scattering at ksnl |
we study the effects of the strange axial form factor and axial mass on both neutral- and charged-current reactions in the quasielastic region within the framework of a relativistic single-particle model. for this purpose, we calculate the differential cross section, the separated cross sections associated with the longitudinal and transverse response functions, the asymmetry for the neutral-current reaction, and the various ratios of the neutral- to charged-current reactions. the calculations are performed for a 12c target at specific incident neutrino (antineutrino) energies of 0.5 and 1.5 gev, or with the flux-averaged incident energies of the miniboone experiment. then, we discuss the dependence of the cross sections, asymmetry, and ratios on the axial mass and strange axial form factor. finally, we compare our calculations with the miniboone experimental data. | influence of axial mass and strange axial form factor on neutrino-nucleus scattering in the quasielastic region |
we consider the neutrino-nucleon scattering to analyse the xf 3 structure function. we solve first numerically the dglap evolution equation, using the laguerre polynomials expansion and monte carlo calculations. what we get for the evolved parton densities is in good agreement with the fitting grsv and cetq parameterizations. we then construct the xf 3 structure function in the bjorken x-space using the laguerre polynomials expansion while we achieve this structure function initially in the mellin moment space. the relations which convert the structure function from the mellin moment space to the bjorken x-space, using the laguerre polynomials, are introduced for the first time in this article. these relations enable us to do the fitting and extract the qcd cut-off parameter which is in good agreement with what is expected. to confirm the calculation we reconstruct the xf 3 structure function directly in bjorken x-space using the evolved parton densities which are obtained, themselves, based on the laguerre expansion. at this stage, to get the evolved parton densities, we employ the qcd cut-off parameter which we get from the fitting. the results for the xf 3 structure function, using the two different described methods, are in good agreement with each other and also with the available experimental data which confirms the validity of our calculations. | analyzing the parton densities and constructing the xf3 structure function, using the laguerre polynomials expansion and monte carlo calculations |
coherent elastic neutrino-nucleus scattering (cevns), the gentlest kind of interaction of a neutrino with an entire nucleus, was first predicted in 1974, but not observed until 2017 by the coherent collaboration. coherent and many other experiments are pursuing further measurements of this low momentum transfer process. we review the physics motivations for these measurements and prospects and status of current and future cevns experiments. | coherent elastic neutrino-nucleus scattering |
in a dedicated run where protons from the fermilab booster were delivered directly to the steel beam dump of the booster neutrino beamline (bnb), the miniboone detector was used to search for the production of sub-gev dark matter particles via vector-boson mediators. the signal searched for was the elastic scattering of dark matter particles off nucleons in the detector mineral oil, with neutrinos being an irreducible background. a review of the experiment, its analysis methods, its results and future perspectives are summarized, demonstrating that beam dump experiments provide a novel and promising approach to dark matter searches. | miniboone-dm: a dark matter search in a proton beam dump |
we propose to detect and study neutrino neutral elastic coherent scattering off atomic nuclei with two-phase emission detector with liquid xenon as a target medium. one of the possible experimental site is a kalinin nuclear power plant (knpp) situated in the russian federation. in this paper we discuss the design of the detector and expected signals and background for this site. | search for elastic coherent neutrino scattering off atomic nuclei at the kalinin nuclear power plant |
exclusive electro-weak processes have peculiar features which make them complementary to usually discussed deeply virtual electroproduction processes such as deep virtual compton scattering or meson production (and the corresponding crossed reactions). they allow in particular single charmed meson production, which we study in two different contexts : electroproduction at an electron ion collider and neutrino-production at a medium energy neutrino facility. we rely on the qcd collinear factorization framework where generalized parton distributions allow physicists to perform a nucleon tomography. | exclusive electro-weak production of a charmed meson at high energy |
new experimental research programs in the field of neutrino physics are calling for new detectors with large masses, high energy resolution and good background rejection capabilities. this paper presents a novel hybrid organic/inorganic scintillator, which is able to improve on all three aspects simultaneously. this scintillator consists of microscopic grains of inorganic crystals suspended in an organic scintillating carrier medium. due to multiple scattering off the crystals, this scintillator appears opaque over longer distances and is intended for use in specialized detectors. thanks to the crystal phase it can natively incorporate a large variety of elements in large quantities, so that a sufficiently large detector can reach elemental loadings on the ton- or multiton scale. at the same time, this composition can produce very high light outputs and provides additional particle identification capabilities. this scintillator concept is expected to provide significant advantages for future neutrino experiments, like searches of neutrinoless double beta experiments and reactor antineutrino physics. | a hybrid organic/inorgaic scintillator for high performance measurements |
good optical transparency is a fundamental requirement of liquid scintillator (ls) detectors. characterizing the transparency of a liquid scintillator to its own emitted light is a key parameter to determine the overall sensitivity of a large-volume detector. the attenuation of light in an optical-pure ls is dominated by rayleigh scattering, which poses an intrinsic limit to the transparency of ls. this work presents a spectrometric approach of measuring the wavelength-dependent scattering length of liquids by applying the einstein-smoluchowski theory to a measurement of scattered light intensity. the scattering lengths of linear alkyl benzene (lab) and ej309-base (di-isopropylnaphthalene, din) were measured and are reported in the wavelength range of 410-520 nm. the spectral peak of scintillation light emitted by a nominal ls is around 430 nm at which the scattering lengths for lab and ej-309-base were determined to be 27.9 ± 2.3 m and 6.1 ± 0.6 m. | a spectrometric approach to measuring the rayleigh scattering length for liquid scintillator detectors |
the katrin experiment aims at a direct and model independent determination of the neutrino mass with 0.2 ev/c2 sensitivity (at 90% c.l.) via a measurement of the endpoint region of the tritium beta-decay spectrum. the main components of the experiment are a windowless gaseous tritium source (wgts), differential and cryogenic pumping sections and a tandem of a pre- and a main-spectrometer, applying the concept of magnetic adiabatic collimation with an electrostatic retardation potential to analyze the energy of beta decay electrons and to guide electrons passing the filter onto a segmented silicon pin detector. one of the important systematic uncertainties of such an experiment are due to energy losses of β-decay electrons by elastic and inelastic scattering off tritium molecules within the source volume which alter the shape of the measured spectrum. to correct for these effects an independent measurement of the corresponding energy loss function is required. in this work we describe a deconvolution method to extract the energy loss function from measurements of the response function of the experiment at different column densities of the wgts using a monoenergetic electron source. | deconvolution of the energy loss function of the katrin experiment |
solid state detectors and cryogenic detectors are widely employed in rare event searches, such as direct dark matter detection or coherent neutrino nucleus scattering experiments. the excellent sensitivity and, consequently, their low energy thresholds are among the most appealing features of such detectors. we present a method to quantify the lowest trigger threshold achievable as a function of the acceptable amount of noise events triggered for the physics case under investigation. we then apply this novel method to existing experimental and simulated data to validate the model we presented. | a method to define the energy threshold depending on noise level for rare event searches |
we present a study on the charge current quasi elastic scattering of ν _μ from nucleon and nuclei which gives a charged muon in the final state. to describe nuclei, the fermi gas model has been used with proposed pauli suppression factor. the diffuseness parameter of the fermi distribution has been obtained using experimental data. we also investigate different parametrizations for electric and magnetic sach's form factors of nucleons. calculations have been made for ccqes total and differential cross-sections for the cases of ν _{μ }-n, ν _{μ }-{^{12}}c and ν _{μ }-{^{56}}fe scatterings and are compared with the data for different values of the axial mass. the present model gives excellent description of measured differential cross-section for all the systems. | charged current quasi elastic scattering of muon neutrino with nuclei |
cosmological observations indicate that our universe contains dark matter (dm), yet we have no measurements of its microscopic properties. whereas the gravitational interaction of dm is well understood, its interaction with the standard model is not. direct detection experiments, the current standard, search for a nuclear recoil interaction and have a low-mass sensitivity edge of order 1 gev. a path to detect dm with mass below 1 gev is the use of accelerators producing boosted low-mass dm. using neutrino detectors to search for low-mass dm is logical due to the similarity of the dm and neutrino signatures in the detector. the miniboone experiment, located at fermilab on the booster neutrino beamline, has produced the first proton beam-dump light dm search results. using dark matter scattering from nucleons 90% confidence limits were set over a large parameter space and, to allow tests of other theories, a model independent dm rate was extracted. | search for light dark matter produced in a proton beam dump |
effects of neutrino charge radius and magnetic moment constraints obtained from the astrophysical observations and reactor experiments, as well as in-medium modifications of the weak and electromagnetic nucleon form factors of the matter on the neutrino electroweak interaction with dense matter, are estimated. we use a relativistic mean-field model for the in-medium effective nucleon mass and quark-meson coupling model for nucleon form factors. we analyze the neutrino scattering cross section and mean free path in cold nuclear matter. we find that the increase of the cross section relative to that without neutrino form factors results in the decrease of the neutrino mean free path when neutrino form factors and the in-medium modifications of the nucleon weak and electromagnetic form factors are simultaneously considered. the quenching of the neutrino mean free path is evaluated to be about 12-58\% for the values of $\mu_\nu = 3 \times 10^{-12} \mu_b$ and $r_\nu = 3.5 \times 10^{-5}~\textrm{mev}^{-1}$ compared with that obtained for the $\mu_\nu =0$ and $r_\nu =0$. the decrease of the neutrino mean free path is expected to decelerate the cooling of neutron stars. each contribution of the neutrino form factors to the neutrino mean free path is discussed. | effects of neutrino magnetic moment and charge radius constraints and medium modifications of the nucleon form factors on the neutrino mean free path in dense matter |
we propose to measure the coherent elastic neutrino nucleus scattering (ce$\nu$ns) using a dual-phase liquid argon time projection chamber (tpc) with 200kg fiducial mass. the detector is expected to be adjacent to the juno-tao experiment and to be about 35m from a reactor core with 4.6gw thermal power at taishan. the antineutrino flux is approximately 6$\times10^{12}$cm$^{-1}$s$^{-1}$ at this location, leading to more than 11,000 coherent scattering events per day in the fiducial mass. however, the nuclear recoil energies concentrate in the sub-kev region, corresponding to less than ten ionisation electrons in the liquid argon. the detection of several ionisation electrons can be achieved in the dual-phase tpc due to the large amplification in the gas region. with a feasible detection threshold of four ionisation electrons, the signal rate is 955 per day. the detector is designed to be shielded well from cosmogenic backgrounds and ambient radioactivities to reach a 16% background-to-signal ratio in the energy region of interest. with the large ce$\nu$ns sample, the expected sensitivity of measuring the weak mixing angle $\sin^{2}\theta_{w}$, and of limiting the neutrino magnetic moment are discussed. in addition, a synergy between the reactor antineutrino ce$\nu$ns experiment and the dark matter experiment is foreseen. | prospects of detecting the reactor $\\bar{\\nu_e}$-ar coherent elastic scattering with a low threshold dual-phase argon time projection chamber at taishan |
nuclear recoils in germanium and silicon are shown to have much larger variance in electron-hole production than their electron recoil counterparts for recoil energies between 10 and 200 kev. this effect—owing primarily to deviations in the amount of energy given to the crystal lattice in response to a nuclear recoil of a given energy—has been predicted by the lindhard model. we parametrize the variance in terms of an intrinsic nuclear recoil fano factor that is 24.3 ±0.2 and 26 ±8 at around 25 kev for silicon and germanium, respectively. the variance has important effects on the expected signal shapes for experiments utilizing low-energy nuclear recoils such as direct dark matter searches and coherent neutrino-nucleus scattering measurements. | intrinsic fano factor of nuclear recoils for dark matter searches |
within weeks of the start of the data taking at the lep accelerator, the aleph, delphi, l3 and opal experiments were able to confirm the existence of just three light neutrino species. this measurement relies on the standard model relation between the `invisible' width of the z-boson and the cross-sections for z-boson production and subsequent decay into hadrons. the full data sample collected by the experiments at and around the z-boson resonance allows a high-precision measurement of the number of light neutrino species as 2.9840 ± 0.0082. the uncertainty is mostly due to the understanding of the low-angle bhabha scattering process used to determine the experimental luminosity. this result is independently confirmed by the elegant direct observation of the e^-e^+ to ν bar{ν}γ process, through the detection of an initial-state-radiation photon in otherwise empty detectors. this result confirms expectations from the existence of three charged leptons species, and contributes to the fields of astrophysics and cosmology. alongside other lep achievements, the precision of this result is a testament to the global cooperation underpinning cern's fourth decade. lep saw the onset of large-scale collaboration across experiments totaling over 2000 scientists, together with a strong partnership within the wider high-energy physics community: from accelerator operations to the understanding of theoretical processes. | the measurement of the number of light neutrino species at lep |
we perform a detailed study of individual hadrons produced in νμ deep inelastic scattering (dis) events reconstructed in the nomad detector. in particular, we analyze the inclusive properties of charged hadrons and the yields of strange particles and resonances. we tune the free parameters which are used to describe the hadronization in the jetset simulation code in order to reproduce the distributions and multiplicities measured in charged current (cc) events. as a result, we obtain an improved description of available data for both charged and neutral current (nc) interactions. our results can be used for the simulation of neutrino interactions in future experiments and for low energy applications. | study of fragmentation parameters in deep inelastic scattering neutrino interactions |
neutrino-electron scattering is a purely leptonic fundamental interaction and therefore provides an important channel to test the standard model, especially at the low energy-momentum transfer regime. we derived constraints on neutrino nonstardard interaction couplings depending on model-independent approaches which are described by a four-fermi pointlike interaction and unparticle physics model with tensorial components. data on $\bar{\nu}_{e}-e$ and $\nu_{e}-e$ scattering from the texono and lsnd experiments, respectively, are used. the upper limits and the allowed regions of scalar, pseudoscalar, and tensorial nonstandard interaction couplings of neutrinos are derived at 90\% confidence level in both one-parameter and two-parameter analysis. new upper limits for tensorial unparticle physics coupling constants and mass parameters are also placed. | constraints on scalar-pseudoscalar and tensorial non-standard interaction and tensorial unparticle couplings from neutrino-electron scattering |
the problem of internal ionization in the beta decay of tritium due to the scattering of a β electron off a bound electron is discussed. the total probability of the process per a single decay event is calculated. the distributions over the momentum and the kinetic energy of a liberated electron are plotted. a correction to the β spectrum produced by internal ionization is determined. the identity of electrons is taken into account in all calculations. the results of calculations of the modified spectrum are of interest for the katrin experiment aimed at measuring the mass of an electron antineutrino. the high-luminosity source also makes it possible to search for kev-scale sterile neutrinos in the middle part of the β spectrum, where the internal ionization effect is significant. | internal ionization of an atom in the β decay of tritium |
in this talk we shortly describe the physics contents of the gibuu transport code, used to describe lepton scattering off nuclei. particular attention will be given to validation of the gibuu in pion-, electron- and photon-induced reactions, which serve as a benchmark for neutrino-induced ones. we mainly concentrate on those properties of benchmark reactions, which are relevant to the region of shallow inelastic scattering (sis). our results in this region are presented for integrated and differential cross sections. comparison with recent minos inclusive data, as well as predictions for the differential cross sections measurable in minerνa and noνa experiments are made. | gibuu and shallow inelastic scattering |
we consider possible effects of neutrino electric charge (millicharge) and charge radius on the neutrino-atom interaction processes such as (i) atomic ionization by neutrino impact and (ii) coherent elastic neutrino-nucleus scattering. the bounds on the neutrino millicharge and charge radius that follow from, respectively, the gemma and coherent experiments are presented and discussed. | constraints on neutrino millicharge and charge radius from neutrino-atom scattering |
we performed a search for event bursts in the xmass-i detector associated with 11 gravitational-wave events detected during ligo/virgo's o1 and o2 periods. simple and loose cuts were applied to the data collected in the full 832 kg xenon volume around the detection time of each gravitational-wave event. the data were divided into four energy regions ranging from kev to mev. without assuming any particular burst models, we looked for event bursts in sliding windows with various time width from 0.02 to 10 s. the search was conducted in a time window between $-$400 and $+$10,000 s from each gravitational-wave event. for the binary neutron star merger gw170817, no significant event burst was observed in the xmass-i detector and we set 90% confidence level upper limits on neutrino fluence for the sum of all the neutrino flavors via coherent elastic neutrino-nucleus scattering. the obtained upper limit was (1.3-2.1)$\times 10^{11}$ cm$^{-2}$ under the assumption of a fermi-dirac spectrum with average neutrino energy of 20 mev. the neutrino fluence limits for mono-energetic neutrinos in the energy range between 14 and 100 mev were also calculated. among the other 10 gravitational wave events detected as the binary black hole mergers, a burst candidate with a 3.0$\sigma$ significance was found at 1801.95-1803.95 s in the analysis for gw151012. however, no significant deviation from the background in the reconstructed energy and position distributions was found. considering the additional look-elsewhere effect of analyzing the 11 gw events, the significance of finding such a burst candidate associated with any of them is 2.1$\sigma$. | search for event bursts in xmass-i associated with gravitational-wave events |
the red100 two-phase liquid xenon emission detector for neutrino coherent scattering experiments is equipped with 38 hamamatsu r11410-20 photomultiplier tubes capable to operate at cryogenic temperatures and made of low background materials. a dedicated characterization procedure has been carried out for each pmt unit to be installed into the detector. the results presented here include single photoelectron analysis, gain curves for a wide range of the bias voltage values, data on dark count rate for 34 pmt samples. peculiar noise characteristics of selected pmt units are analysed and discussed. | characterization of the low-background hamamatsu r11410- 20 cryogenic pmts for the red100 detector |
we present low energy recoil detection results in the kev energy region, from measurements performed with the spherical proportional counter (spc). an ${}^{241}am-{}^{9}{be}$ fast neutron source is used in order to obtain neutron-nucleus elastic scattering events inside the gaseous volume of the detector. the detector performance in the $kev$ energy region was resolved by observing the $5.9\ kev$ line of a ${}^{55}fe$ x-ray source, with energy resolution of $9\%$ ($\sigma$). the toolkit geant4 was used to simulate the irradiation of the detector by an ${}^{241}am-{}^{9}{be}$ source, while srim was used to calculate the ionization quenching factor (iqf). the geant4 simulated energy deposition spectrum in addition with the srim calculated quenching factor provide valuable insight to the experimental results. the performance of the spc in low energy recoil detection makes the detector a good candidate for a wide range of applications, including supernova or reactor neutrino detection and dark matter (wimp) searches (via coherent elastic scattering). | low energy recoil detection with a spherical proportional counter |
the study of neutrino interactions has recently experienced a renaissance, motivated by the fact that neutrino oscillation experiments depend critically on an accurate models of neutrino interactions. these models have to predict not only the signal and background populations that oscillation experiments see at near and far detectors, but they must also predict how the neutrino's energy which enters a nucleus gets transferred to energies of the particles that leave the nucleus after the neutrino interacts. over the past year there have been a number of new results on many different neutrino (and antineutrino) interaction channels using several different target nuclei. these results are often not in agreement with predictions extraolated from charged lepton scattering measurements, or even from predictions anchored to neutrino measurements on deuterium. these new measurements are starting to give the community the handles needed to improve the theoretical description of neutrino interactions, which ultimately pave the way for precision oscillation measurements. this report briefly summarizes recent results and points out where those results differ from the predictions based on current models. | the state of the art of neutrino cross section measurements |
we present our recent progress in the description of neutrino-nucleus interaction in the gev region, of interest for ongoing and future oscillation experiments. in particular, we discuss the weak excitation of two-particle-two-hole states induced by meson exchange currents in a fully relativistic framework. we compare the results of our model with recent measurements of neutrino scattering cross sections, showing the crucial role played by two-nucleon knockout in the interpretation of the data. | the role of meson exchange currents in charged current (anti)neutrino-nucleus scattering |
we present studies of proton fluxes in the t10 beamline at cern. a prototype high pressure gas time projection chamber (tpc) was exposed to the beam of protons and other particles, using the 0.8 gev/c momentum setting in t10, in order to make cross section measurements of low energy protons in argon. to explore the energy region comparable to hadrons produced by gev-scale neutrino interactions at oscillation experiments, i.e., near 0.1 gev of kinetic energy, methods of moderating the t10 beam were employed: the dual technique of moderating the beam with acrylic blocks and measuring scattered protons off the beam axis was used to decrease the kinetic energy of incident protons, as well as change the proton/minimum ionising particle (mip) composition of the incident flux. measurements of the beam properties were made using time of flight systems upstream and downstream of the tpc. the kinetic energy of protons reaching the tpc was successfully changed from $\sim0.3$ gev without moderator blocks to less than 0.1 gev with four moderator blocks (40 cm path length). the flux of both protons and mips off the beam axis was increased. the ratio of protons to mips vary as a function of the off-axis angle allowing for possible optimisation of the detector to select the type of required particles. simulation informed by the time of flight measurements show that with four moderator blocks placed in the beamline, ($5.6 \pm 0.1$) protons with energies below 0.1 gev per spill traversed the active tpc region. measurements of the beam composition and energy are presented. | off-axis characterisation of the cern t10 beam for low momentum proton measurements with a high pressure gas time projection chamber |
we determine the effective theory of neutrino-electron and neutrino-quark scattering and provide the most precise up-to-date prediction for neutrino-electron scattering cross sections quantifying errors for the first time to be of order $0.2-0.4~\%$. radiative corrections in the theory with electron and neutrinos only involve three effective couplings. one is the fermi constant which is known with sub-ppm accuracy. another one has a small error of order $0.02~\%$. the uncertainty of the third one is limited by the knowledge of hadronic contributions to charge-isospin vector-vector correlation function. | how well do we know neutrino-electron scattering? eft approach |
the synthesis of hyper-heavy elements is investigated under conditions simulating neutron star environment. the constrained molecular dynamics approach is used to simulate low energy collisions of extremely n -rich nuclei. a new type of the fusion barrier due to a "neutron wind" is observed when the effect of neutron star environment (screening of coulomb interaction) is introduced implicitly. when introducing also a background of surrounding nuclei, the nuclear fusion becomes possible down to temperatures of 108 k and synthesis of extremely heavy and n -rich nuclei appears feasible. a possible existence of hyper-heavy nuclei in a neutron star environment could provide a mechanism of extra coherent neutrino scattering or an additional mechanism, resulting in x-ray burst or a gravitational wave signal and, thus, becoming another crucial process adding new information to the suggested models on neutron star evolution. | investigating the possible existence of hyper-heavy nuclei in a neutron-star environment |
the rotating lepton model (rlm) of composite particles is used in conjunction with special relativity, the equivalence principle of inertial and gravitational mass, and the de broglie wavelength equation, to compute analytically the masses, potential energies and hamiltonians of 9 hadrons, 3 mesons and 3 bosons without any adjustable parameters. the model is also used to derive analytical formulae for their confining force and internal pressure and to compare with the experimental values measured recently via deeply virtual compton scattering (dvcs) and computed via lattice quantum chromodynamics (lqcd) calculations. agreement between the rlm computed masses and the experimental ones is, surprisingly, within 1% and supports the previously proposed notion that the strong force can be modeled as a relativistic gravitational force between neutrinos, and that the weak force can be modeled as a relativistic gravitational force between electrons or positrons with neutrinos or antineutrinos. | computation of the masses, energies and internal pressures of hadrons, mesons and bosons via the rotating lepton model |
spin-m1 excitations of nuclei are important for describing neutrino reactions in supernovae or in neutrino detectors since they are allowed transitions mediated by neutral current neutrino interactions. the spin-m1 excitation strength distributions in self-conjugate n = z nuclei were studied by proton inelastic scattering at forward angles for each of isovector and isoscalar excitations as reported in h. matsubara et al., phys. rev. lett. 115, 102501 (2015). the experiment was carried out at the research center for nuclear physics, osaka university, employing a proton beam at 295 mev and the high-resolution spectrometer grand raiden. the measured cross-section of each excited state was converted to the squared nuclear matrix elements of spin-m1 transitions by applying a unit cross-section method. comparison with predictions by a shell-model has revealed that isoscalar spin-m1 strengths are not quenched from the prediction although isovector spin-m1 strengths are quenched similarly with gamow-teller strengths in charged-current reactions. this finding hints at an important origin of the quenching of the strength relevant to neutrino scattering, that is, the proton-neutron spin-spin correlation in the ground state of the target nucleus. in this manuscript we present the details of the unit cross-section method used in the data analysis and discuss the consistency between the quenching of the isoscalar magnetic moments and that of the isoscalar spin-m1 strengths. | quenching of isovector and isoscalar spin-m1 excitation strengths in n=z nuclei |
the connie experiment (coherent neutrino nucleus interaction experiment) is currently collecting reactor neutrino data to search for the undiscovered standard model process of coherent neutrino-nucleus scattering (cnns). the detector is composed of a silicon target of thick, fully-depleted, low-noise ccd detectors. results from data collected in 2015 indicate backgrounds are controlled, and allow an estimate of sensitivity to be presented for a larger scale detector. a 2016 upgrade, adding additional target mass, and reducing readout noise, has been performed, increasing the total yield of signal events by a factor of 30, and already yielding science-quality data. low-energy nuclear calibrations have been performed, enabling calibration down to the device energy threshold. an estimate of the sensitivity expected for measuring the coherent neutrino process is presented. future prospects with improved detector energy thresholds are estimated. | results from 2015 and the 2016 upgrade of the connie experiment for detecting coherent neutrino nucleus scattering |
the mössbauer spectroscopy is proposed as an alternative experimental technique to be pursued in the detection of coherent elastic ν-nucleus scattering (cenns). the neutrino transferred energy in the neutrino-nucleus interaction causes a perturbation at the nuclear level structure of the mössbauer isotope, leading to a displacement of the isomeric peak of the electromagnetic resonance. we calculate this isomeric shift correction due to the occurrence of cenns and show that this quantity can be measured with enough precision in a typical mössbauer spectroscopic experiment. we also shown that a reasonable number of events is expected and allow to extract the correction in the isomeric shift in a typical neutrino reactor flux. this isomeric shift correction is pointed out as a figure of merit for signature of cenns in our proposal. | searching signature of neutrino-nucleus coherent scattering with mössbauer spectroscopy |
comet (coherent muon to electron transition, j-parc, japan) is one of the experiments that studies extensions of the standard model (sm) of elementary particle physics. the main purpose of the comet experiment is to search for charged lepton flavor violating neutrinoless conversion of muons into electrons in the field of a nucleus (μ-e conversion, μ-n → e-n). the goal is to achieve a sensitivity to the branching ratio superior to 10-17, that four orders of magnitude smaller than the present limit. in the experiment a straw detector will be used to measure the momentum of the signal electrons from the μ-e conversion. in order to satisfy the requirements of the momentum measurements, we plan to develop a planar tracking device consisting of thin-wall straws made with an extremely light material to reduce multiple scattering and that is capable of operation in vacuum. research the mechanical properties of straws will allow us to choose their optimal tension, to estimate the influence of the temperature and humidity, to assess the straws service life in the experiment, which we define as the tension relaxation time to the minimum working value. | properties of straw tubes for the tracking detector of the comet experiment |
we investigated the in-medium effect by density-dependent axial and weak-vector form factors on muon-neutrino ({{ν }μ }) and anti-muon-neutrino ({{\bar{ν }}μ }) scattering in the quasi-elastic (qe) region from nucleons (n*) bound in a nucleus or immersed in a nuclear medium via neutral current (nc) and charged current (cc). for the density-dependent form factors, we exploited a quark-meson-coupling (qmc) model. we found that the {{ν }μ }({{\bar{ν }}μ })-{{n}*} scattering cross sections via nc in the qe region usually decrease with an increased medium density, while those using cc were increased. however, their rate of change was sensitive to the four-momentum transfer given to a bound nucleon through scattering. we compared these results obtained by the elementary process corrected by the in-medium effect to the bnl and miniboone data, which measured {{ν }μ } scattering cross sections per nucleon through {{ν }μ } - 12c scattering in 12c composite targets. the incident energy range was 550 \lt {{e}ν }\lt 3000 mev. we increased the energy up to 100 gev to compare our results to the nomad experimental data. in order to study the density effects on a nucleon embedded in 12c, we exploited the qmc form factors evaluated at ρ =0.5{{ρ }o}, where the normal density {{ρ }o}∼ 0.15 f{{m}-3}. the strangeness contributions in nc scattering are also incorporated into the form factors for comparison with experimental data. our numerical results show that most of the experimental data can be explained in a satisfactory manner by the density-dependent elementary process, but there are some remaining deviations resulting from the nuclear structure, particularly in the low and high momentum-transfer regions. | in-medium effect with muon-neutrino and anti-muon-neutrino quasi-elastic scattering from 12c nucleons |
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