Inclusive and exclusive neutrino-nucleus cross sections and the reconstruction of the interaction kinematics

Abstract

We present a full kinematic analysis of neutrino-nucleus charged current quasielastic interactions based on the Local Fermi Gas model and the Random Phase Approximation. The model was implemented in the NEUT Monte Carlo framework, which allows us to investigate potentially measurable observables, including hadron distributions. We compare the predictions simultaneously to the most recent T2K and MINERvA charged current (CC) inclusive, CC0π and transverse kinematic-imbalance variable results. We pursuit a microscopic interpretation of the relevant reaction mechanisms, with the aim to achieving in neutrino oscillation experiments a correct reconstruction of the incoming neutrino kinematics, free of conceptual biasses. Such study is of the utmost importance for the ambitious experimental program which is underway to precisely determine neutrino properties, test the three-generation paradigm, establish the order of mass eigenstates and investigate leptonic CP violation.

The NEUT neutrino interaction simulation program library

“…The NEUT implementation of the GRFG cross section follows the prescription by Smith and Moniz [12]. The LFG implementation uses the model by Nieves et al [13] and includes an updated removal energy treatment implemented by Bourguille et al [14]. Simple Fermi-gas models tend to over-predict the cross section for forward going leptons, as a result this model takes into account long-and short-range correlations of nucleons using the random phase approximation, suppressing the cross section for low 4-momentum transfer [15].…”

A New Generation of Neutrino Cross Section Experiments: Challenges and Opportunities

“…The effort of the theoretical community particularly focused on this channels. Many theoretical calculations of CCQE+2p-2h and CC0π flux integrated differential cross sections have been performed by different groups [54,[70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87]. Nowadays several calculations agree on the crucial role of the multinucleon emission in order to explain the MiniBooNE [24,25], T2K [50,[88][89][90][91], MINERvA [51,92] and MicroBooNE [52] cross sections.…”

“…Semi-inclusive CC1p0π cross sections function of muon and proton kinematics have been published also by MicroBooNE [26,52]. The theoretical investigation on semi-inclusive cross sections [85,86,[125][126][127][128][129] and on transverse kinematic imbalances [75,120,130] are only at the beginning, as well as the studies related to the emission of nucleon pairs induced by meson exchange currents and short range correlations [85,86,131,132].…”

“…sections, in general dominated by the spin-transverse response, becomes sensitive to the spin-longitudinal one which is characterized not only by low-energy giant resonances but also by high-energy collective states such as coherent mixture of ∆-hole states and pions[72,103]; • Even in neutrino beams, such as T2K/HK and MiniBooNE/MicroBooNE, which induce nuclear excitations dominated by quasielatic, 2p-2h and 1π production, higher energy excitations up to the DIS contribute, as illustrated for example in Refs [75,82]…”

“….The ultimate goal should be the development of a theoretical unified approach for the treatment of all nuclear excitations, from low-energy giant resonances to DIS. For the moment flux-integrated differential cross sections calculations are available from QE to DIS in the case of the GiBUU[104] implementation of the transport theory[81][82][83] and from and from QE to 1 pion production induced by ∆-resonance excitations in the approaches of Martini et al[49,70,72], Nieves et al[54,75,93] and SuSA/SuSAv2[76,80,[105][106][107].Promising approaches exploiting the factorisation of the nuclear cross section, based on spectral functions…”