We first present the implementation and validation of the SuSAv2-MEC 1p1h and 2p2h models in the GENIE neutrino-nucleus interaction event generator and a comparison of the subsequent predictions to ...measurements of lepton and hadron kinematics from the T2K experiment. These predictions are also compared to those of other available models in GENIE. We further compare semi-inclusive predictions of the implemented 1p1h model to those of the microscopic model on which SuSAv2 is based-relativistic mean field-to begin to test the validity of widely used "factorization" assumptions employed by generators to predict hadron kinematics from inclusive input models. The results highlight that a more precise treatment of hadron kinematics in generators is essential in order to attain the few-% level uncertainty on neutrino interactions necessary for the next generation of accelerator-based long-baseline neutrino oscillation experiments.
We present our recent progress on the relativistic modeling of electron-nucleus reactions and compare our predictions with inclusive C super(12)(e, e') experimental data in a wide kinematical region. ...The model, originally based on the superscaling phenomenon shown by electron-nucleus scattering data, has recently been improved through the inclusion of relativistic mean field theory effects that take into account the enhancement of the quasielastic transverse scaling function compared with its longitudinal counterpart. In this work, we extend the model to include the complete inelastic spectrum-resonant, nonresonant and deep inelastic scattering. We also discuss the impact of meson-exchange currents through the analysis of two-particle two-hole contributions to electromagnetic response functions evaluated within the framework of the relativistic Fermi gas, considering for the first time not only the transverse but also the longitudinal channel. The results show quite good agreement with data over the whole range of energy transfer, including the dip region between the quasielastic peak and the Delta resonance.
The extraction of neutrino mixing parameters from accelerator-based neutrino-oscillation experiments relies on proper modeling of neutrino-nucleus scattering processes using neutrino interaction ...event generators. Experimental tests of these generators are difficult due to the broad range of neutrino energies produced in accelerator-based beams and the low statistics of current experiments. Here we overcome these difficulties by exploiting the similarity of neutrino and electron interactions with nuclei to test neutrino event generators using high-precision inclusive electron-scattering data. To this end, we revised the electron-scattering mode of the genie event generator (e-genie) to include electron-nucleus bremsstrahlung radiation effects and to use, when relevant, the exact same physics models and model parameters, as the standard neutrino-scattering version. We also implemented new models for quasielastic (QE) scattering and meson exchange currents (MECs) based on the theory-inspired super scaling approach SuSAv2. Comparing the new e-genie predictions with inclusive electron-scattering data, we find an overall adequate description of the data in the QE- and MEC-dominated lower energy transfer regime, especially when using the SuSAv2 models. Higher energy transfer interactions, which are dominated by resonance production, are still not well modeled by e-genie.
We compare the results of the SuSAv2 model including meson-exchange currents (MEC) with the recent measurement of the quasielasticlike double differential antineutrino cross section on a hydrocarbon ...performed by the MINERvA Collaboration C. E. Patrick et al. (MINERvA Collaboration), Phys. Rev. D 97, 052002 (2018). The relativistic nature of the model makes it suitable to describe these data, which correspond to a mean beam energy of 3.5 GeV. The standard SuSAv2 model predictions agree well with the data without needing any additional or tuned parameter. The role of longitudinal MEC is non-negligible and improves the agreement with the data. We also consider the impact of different treatments of the Δ-resonance propagator in the two-body currents on the data comparison.
We present the results of semi-inclusive neutrino-nucleus cross sections within the plane wave impulse approximation (PWIA) for three nuclear models: relativistic Fermi gas, independent-particle ...shell model, and natural orbital shell model in comparison with the available CC 0 π measurements from the T2K, MINER ν A , and MicroBooNE collaborations where a muon and at least one proton are detected in the final state. Results are presented as a function of the momenta and angles of the final particles, as well as in terms of the imbalances between proton and muon kinematics. The present semi-inclusive formalism is based on fully relativistic microscopic calculations and numerical integrations to produce both lepton and hadron kinematics without relying on further approximations. The analysis reveals that contributions beyond PWIA are crucial to explain the experimental measurements and that the study of correlations between final-state proton and muon kinematics can provide valuable information on relevant nuclear effects such as the Fermi motion and final-state interactions.
We present a detailed study of charged-current neutrino-nucleus reactions in a fully relativistic framework and comparisons with recent experiments spanning an energy range from hundreds of MeV up to ...100 GeV within the superscaling approach, which is based on the analysis of electron-nucleus scattering data and has been recently improved with the inclusion of relativistic mean field theory effects. We also evaluate and discuss the impact of two-particle two-hole meson-exchange currents on neutrino-nucleus interactions through the analysis of two-particle two-hole axial and vector contributions to weak response functions in a fully relativistic Fermi gas. The results show a fairly good agreement with experimental data over the whole range of neutrino energies.
PDF
