Electroweak nuclear response at moderate momentum transfer

TL;DR

This paper evaluates the accuracy of the nuclear electroweak current expansion at moderate momentum transfer, finding that higher-order terms are necessary for precise electron and neutrino scattering predictions.

Contribution

It introduces a detailed analysis of the convergence of the electroweak current expansion and demonstrates the importance of including higher-order terms for accurate scattering cross section calculations.

Findings

Leading-order approximation is insufficient at 300 MeV.

Higher-order terms improve the accuracy of scattering cross section estimates.

Correlated wave functions and cluster expansion formalism effectively model nuclear responses.

Abstract

We discuss the convergence of the expansion of the nuclear electroweak current in powers of |k|/M, where M is the nucleon mass and k denotes either the momentum transfer or the momentum of the struck nucleon. We have computed the electron and neutrino scattering cross sections off uniform nuclear matter at equilibrium density using correlated wave functions and the cluster expansion formalism. The results of our work suggest that the proposed approach provides accurate estimates of the measured electron scattering cross sections. On the other hand, the description of the current based on the widely used leading-order approximation does not appear to be adequate, even at momentum transfer as low as 300 MeV.