Reduced cross-section in Electron-Ion Colliders at small $x$

TL;DR

This paper analyzes the nuclear reduced cross section in electron-ion collisions at small Bjorken-x, focusing on the impact of the longitudinal structure function and gluon density behavior for different nuclei.

Contribution

It investigates the impact parameter dependence of nuclear structure functions and cross sections at small x using the HIJING2.0 model, highlighting nuclear effects in electron-ion collisions.

Findings

The nuclear reduced cross section varies with impact parameter.

The behavior of the longitudinal structure function $F^{A}_{L}$ is influenced by nuclear size.

Gluon density expansion impacts the cross section at small x.

Abstract

The nuclear reduced cross section $\sigma^{A}_{r}$, in the kinematic range of the electron-Ion collider with center-of-mass energy $\sqrt{s}=140~\mathrm{GeV}$ and $y{\leq}1$, is discussed. The importance of the nuclear longitudinal structure function $F^{A}_{L}$ and its behavior owing to the impact parameter for the heavy and light nucleus of Pb-208 and C-12 at $Q^2=5$ and $10~\mathrm{GeV}^2$ is considered. The dependence of the ratios $R^{A}_{F_{L}}$ and $R^{A}_{\sigma}$ on the impact parameter and the expanding point of the gluon density at small $x$ are investigated. The factorized form of parton distributions in nuclei is used in HIJING2.0 model.