Nuclear EMC Effect in a Statistical Model

TL;DR

This paper uses a statistical model with light-front variables to explain the nuclear EMC effect, predicting parton distribution ratios that can distinguish it from other models.

Contribution

It introduces a temperature-dependent statistical model to describe the EMC effect and predicts specific parton ratio behaviors for different nuclei.

Findings

Results agree with experimental data for various nuclei.

Predicted parton ratios differ from other models, offering experimental testability.

Larger atomic number corresponds to lower temperature and bigger volume.

Abstract

A simple statistical model in terms of light-front kinematic variables is used to explain the nuclear EMC effect in the range $x \in [0.2,~0.7]$, which was constructed by us previously to calculate the parton distribution functions (PDFs) of the nucleon. Here, we treat the temperature $T$ as a parameter of the atomic number $A$, and get reasonable results in agreement with the experimental data. Our results show that the larger $A$, the lower $T$ thus the bigger volume $V$, and these features are consistent with other models. Moreover, we give the predictions of the quark distribution ratios, \emph{i.e.}, $q^A(x) / q^D(x)$, $\bar{q}^A(x) / \bar{q}^D(x)$, and $s^A(x) / s^D(x)$, and also the gluon ratio $g^A(x) / g^D(x)$ for iron as an example. The predictions are different from those by other models, thus experiments aiming at measuring the parton ratios of antiquarks, strange quarks, and gluons can provide a discrimination of different models.