New evaluation of axial nucleon form factor from electron- and neutrino-scattering data and impact on neutrino-nucleus cross-section

TL;DR

This paper reevaluates the nucleon axial form factor using combined electron and neutrino scattering data within a two-component model, revealing significant differences from the dipole model and analyzing their impact on neutrino-nucleus cross-section predictions.

Contribution

It introduces a new joint fitting approach to determine the axial form factor with a two-component model, improving the understanding of neutrino-nucleon interactions.

Findings

Sizable differences in axial form factor compared to dipole model

Impact on neutrino-nucleus cross-section predictions quantified

Comparisons with T2K and MINERvA data provided

Abstract

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 model, based on the Relativistic Mean Field and including the contribution of two-body currents. How the different parametrizations of the axial form factor affect the cross-section prediction is assessed in full details and comparisons to recent T2K and MINERvA data are presented.