Nuclear medium effects in $F_{2A}^{EM}(x,Q^2)$ and $F_{2A}^{Weak}(x,Q^2)$ structure functions

TL;DR

This paper investigates nuclear medium effects on electromagnetic and weak structure functions in nuclei, highlighting differences observed in experimental data and analyzing various nuclear effects using a microscopic model.

Contribution

It provides a detailed microscopic analysis of nuclear medium effects on $F_{2A}^{EM}$ and $F_{2A}^{Weak}$ structure functions across a wide kinematic range, incorporating multiple nuclear phenomena.

Findings

Differences between electromagnetic and weak structure functions in nuclei are confirmed.

Nuclear effects such as Fermi motion, binding, and mesonic contributions significantly modify structure functions.

Results agree with experimental data for iron nuclei.

Abstract

Recent phenomenological analysis of experimental data on DIS processes induced by charged leptons and neutrinos/antineutrinos beams on nuclear targets by CTEQ collaboration has confirmed the observation of CCFR and NuTeV collaborations, that weak structure function $F_{2A}^{Weak} (x,Q^2)$ is different from electromagnetic structure function $F_{2A}^{EM} (x,Q^2)$ in a nucleus like iron, specially in the region of low $x$ and $Q^2$. In view of this observation we have made a study of nuclear medium effects on $F_{2A}^{Weak} (x,Q^2)$ and $F_{2A}^{EM} (x,Q^2)$ for a wide range of $x$ and $Q^2$ using a microscopic nuclear model. We have considered Fermi motion, binding energy, nucleon correlations, mesonic contributions from pion and rho mesons and shadowing effects to incorporate nuclear medium effects. The calculations are performed in a local density approximation using a relativistic nucleon spectral function which includes nucleon correlations. The numerical results in the case of iron nucleus are compared with the experimental data.