The extraction of neutrino oscillation parameters often requires the unambiguous identification of the reaction mechanism to be used for the energy determination. The use of nuclear targets and of beams with broad energy distributions complicates this task because it requires the reliable description of many different elementary processes and the use of event generators to isolate and identify them. In this talk I briefly summarize our present understanding of this task.
Interpretation of current and future neutrino oscillation and electron scattering experiments requires knowledge of lepton-nucleon and lepton-nucleus interactions at the percent level. We study the exchange of photons between charged particles and the nuclear medium for (anti)neutrino-, electron-, and muon-induced reactions inside a large nucleus. While quantum electrodynamics (QED)-medium contributions are formally suppressed by two powers of the electromagnetic coupling constant $α$ when compared to the leading-order cross sections, low-energy modes and the nuclear size enhance the effect by…
We examine the importance of conserving the vector current in calculating low-energy neutrino-nucleus interactions by implicitly invoking Siegert's Theorem in describing the vector transverse electric current. We find that at low neutrino energies (E? <50 MeV), Siegert's Theorem can change neutrino cross sections for normal-parity non-spin-flip excitations by about a factor of two.The same is true of muon capture rates. At higher neutrino energies the effect of Siegert's Theorem diminishes, and by about 100 MeV the effect is very small.
The European Spallation Source (ESS), currently finishing its construction, will soon provide the most intense neutron beams for multi-disciplinary science. At the same time, it will also produce a high-intensity neutrino flux with an energy suitable for precision measurements of Coherent Elastic Neutrino-Nucleus Scattering. We describe some physics prospects, within and beyond the Standard Model, of employing innovative detector technologies to take the most out of this large flux. We show that, compared to current measurements, the ESS will provide a much more precise understanding of neutri…
Coherent elastic neutrino scattering on the 40Ar nucleus is computed with coupled-cluster theory based on nuclear Hamiltonians inspired by effective field theories of quantum chromodynamics. Our approach is validated by calculating the charge form factor and comparing it to data from electron scattering. We make predictions for the weak form factor, the neutron radius, and the neutron skin, and estimate systematic uncertainties. The neutron-skin thickness of 40Ar40 is consistent with results from density functional theory. Precision measurements from coherent elastic neutrino-nucleus scatterin…
High-energy neutrino-nucleus interactions are discussed by considering neutrino-oscillation experiments and ultra-high-energy cosmic neutrino interactions. The largest systematic error for the current neutrino oscillation measurements comes from the neutrino-nucleus interaction part, and its accurate understanding is essential for high-precision neutrino physics, namely for studying CP violation in the lepton sector. Depending on neutrino beam energies, quasi-elastic, resonance, Regge, or/and deep inelastic scattering (DIS) processes contribute to the neutrino cross section. It is desirable to…
Final State Interactions Effects in Neutrino-Nucleus Interactions
末态相互作用的影响进行了讨论的背景下，中微子-核相互作用的蒙特卡罗模拟。形成时间的作用进行了解释和几种模型描述这种效果进行了比较。评述了对FSI效应敏感的各种观测量，包括π-核相互作用和后半球强子产额。本文介绍了NuWro Monte Carlo中微子事件发生器，并论证了它理解$\sim 1$ GeV中微子通量实验中中性电流$π^0$产生数据的能力。
We discuss various aspects of a neutrino physics program that can be carried out with the neutrino Beam-Dump eXperiment DRIFT ($ν$BDX-DRIFT) detector using neutrino beams produced in next generation neutrino facilities. $ν$BDX-DRIFT is a directional low-pressure TPC detector suitable for measurements of coherent elastic neutrino-nucleus scattering (CE$ν$NS) using a variety of gaseous target materials which include carbon disulfide, carbon tetrafluoride and tetraethyllead, among others. The neutrino physics program includes standard model (SM) measurements and beyond the standard model (BSM) ph…
We calculate the charged-current cross sections obtained at the T2K off-axis near detector for $ν_μ$-induced events without pions and any number of protons in the final state using transport theory as encoded in the GiBUU model. In a comparison with recent T2K data the strength of the 2p2h multinucleon correlations is determined. Linking this to the isospin (T) of the initial nuclear state, it is found that T=0 leads to a significantly better fit of the recent cross sections obtained by T2K, thus achieving consistency of the 2p2h multi-nucleon correlation contributions between electron-nucleus…
Coherent elastic neutrino-nucleus scattering (CE$ν$NS), a process recently measured for the first time at ORNL's Spallation Neutron Source, is directly sensitive to the weak form factor of the nucleus. The European Spallation Source (ESS), presently under construction, will generate the most intense pulsed neutrino flux suitable for the detection of CE$ν$NS. In this paper we quantify its potential to determine the root mean square radius of the point-neutron distribution, for a variety of target nuclei and a suite of detectors. To put our results in context we also derive, for the first time, …
The Super-Scaling Approach (SuSA) model, based on the analogies between electron and neutrino interactions with nuclei, is reviewed and its application to the description of neutrino-nucleus scattering is presented. The contribution of both one- and two-body relativistic currents is considered. A selection of results is presented where theoretical predictions are compared with cross section measurements from the main ongoing neutrino oscillation experiments.
In this article, we present the charged and neutral current 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 approach. We calculate the integrated cross sections for neutrino-carbon, neutrino-iron and neutrino-oxygen scattering. The results of integrated cross-section calculations are compared with the measured …
We illustrate the connection between electron and neutrino scattering off nuclei and show how the former process can be used to constrain the description of the latter. After reviewing some of the nuclear models commonly used to study lepton-nucleus reactions, we describe in detail the SuSAv2 model and show how its predictions compare with the available electron- and neutrino-scattering data over the kinematical range going from the quasi-elastic peak to pion-production and highly inelastic scattering.
We present a novel lepton-nucleus event generator: ACHILLES, A CHIcagoLand Lepton Event Simulator. The generator factorizes the primary interaction from the propagation of hadrons in the nucleus, which allows for a great deal of modularity, facilitating further improvements and interfaces with existing codes. We validate our generator against high quality electron-carbon scattering data in the quasielastic regime, including the recent CLAS/e4v reanalysis of existing data. We find good agreement in both inclusive and exclusive distributions. By varying the assumptions on the propagation of knoc…
Rescattering following a neutrino-nucleus reaction changes the number, energy, and direction of detectable hadrons. In turn, this affects the selection and kinematic distributions of subsamples of neutrino events used for interaction or oscillation analysis. This technical note focuses on three forms of two-body rescattering. Elastic hadron+nucleus scattering primarily changes the direction of the hadron with very little energy transfer. Secondly, a hadron+nucleon quasi-elastic process leads to the knockout of a single struck nucleon, possibly with charge exchange between the two hadrons. Also…
We present our recent progress on the relativistic modeling of neutrino-nucleus reactions for their implementation in MonteCarlo event generators (GENIE, NEUT) employed in neutrino oscillation experiments. We compare charged-current neutrino and antineutrino cross sections obtained within the SuSAv2 model, which is based on the Relativistic Mean Field theory and on the analysis of the superscaling behavior exhibited by ($e,e'$) data. We also evaluate and discuss the impact of multi-nucleon excitations arising from 2p-2h states excited by the action of weak forces in a fully relativistic framew…
A joint fit to neutrino-nucleon scattering and pion electroproduction data is performed to evaluate the nucleon axial form factor in the two-component model consisting of a three-quark intrinsic structure surrounded by a meson cloud. Further constrains on the model are obtained by re-evaluating the electromagnetic form factor using electron scattering data. The results of the axial form factor show sizable differences with respect to the widely used dipole model. The impact of such changes on the Charged-Current Quasi-Elastic neutrino-nucleus cross-section is evaluated in the SuSAv2 nuclear mo…
We review the recent progress in modelling neutrino-nucleus scattering, in a framework based on scaling which describes simultaneously the nuclear response to electromagnetic and weak probes. The study is relevant for the analysis of neutrino oscillation data and the design of the next generation experiments Hyper-Kamiokande and DUNE.
We present a study of coherent pion production in neutrino-nucleus interactions using the formalism based on partially conserved axial current theorem which connects the neutrino-nucleus cross section to the pion-nucleus elastic scattering cross section. Pion-nucleus elastic scattering cross section is calculated using Glauber model which takes three inputs, nuclear densities, pion-nucleon cross section and $α_{πN}$ which is the ratio of real to imaginary part of $πN$ forward scattering amplitude, for which the parametrizations are obtained from measured data. We calculate the differential and…
