Scaling Properties of Two-Particle-Two-Hole Responses in Asymmetric Nuclei for Neutrino Scattering within the Relativistic Mean-Field Framework

TL;DR

This paper analyzes how two-particle-two-hole responses in asymmetric nuclei affect neutrino scattering, introducing a scaling method that accurately predicts responses across various nuclei within the relativistic mean-field framework.

Contribution

It presents a novel scaling prescription based on nuclear parameters, enabling accurate response predictions for diverse nuclei in neutrino scattering models.

Findings

Scaling deviations are typically below 10% across nuclei.

The model accurately describes electron-scattering data.

The parametrization facilitates extension to different nuclear targets.

Abstract

We perform a systematic analysis of the nuclear dependence of two-particle-two-hole meson-exchange current contributions to inclusive lepton-nucleus scattering within the relativistic mean-field framework. We present microscopic calculations of nuclear responses for a set of 17 nuclei, ranging from helium to uranium, using a model with different Fermi momenta for protons and neutrons. We propose a novel scaling prescription based on the two-particle phase space and key nuclear parameters. The resulting description is accurate over a wide range of nuclear targets, with typical deviations below 10\%, and allows for a separate treatment of the different emission channels. In addition, a consistent benchmark against electron-scattering data is provided. The parametrization presented provides a practical framework for extending the responses to different nuclear targets in neutrino event generators.