Nuclear dependence of the 2p2h electroweak response in the Relativistic Fermi Gas model

TL;DR

This study investigates meson-exchange two-body currents in lepton-nucleus scattering within the Relativistic Fermi Gas model, revealing a unique nuclear response scaling that impacts neutrino oscillation experiment analyses.

Contribution

It provides new insights into the nuclear response scaling behavior of meson-exchange currents, differing from quasielastic responses, aiding neutrino experiment modeling.

Findings

Nuclear response functions scale as A k_F^2 at their peaks.

This scaling behavior differs from the quasielastic response.

Results are relevant for neutrino oscillation Monte Carlo simulations.

Abstract

We present the results of a recent study of meson-exchange two-body currents in lepton-nucleus inclusive scattering at various kinematics and for different nuclei within the Relativistic Fermi Gas model. We show that the associated nuclear response functions at their peaks scale as $A k_F^2$, for Fermi momentum $k_F$ going from 200 to 300 MeV/c and momentum transfer $q$ from $2k_F$ to 2 GeV/c. This behavior is different from what is found for the quasielastic response, which scales as $A/k_F$. This result can be valuable in the analyses of long-baseline neutrino oscillation experiments, which need to implement these nuclear effects in Monte Carlo simulations for different kinematics and nuclear targets.