# Unveiling saturation effects from nuclear structure function measurements at the EIC

## TL;DR

This paper investigates how future Electron-Ion Collider measurements could reveal non-linear saturation effects in nuclear structure functions by comparing pseudodata generated from saturation models with existing nuclear parton distribution functions using Bayesian reweighting.

## Contribution

It introduces a method to identify saturation effects by analyzing the disagreement between pseudodata from saturation models and current nPDFs, highlighting potential signals of non-linear QCD dynamics.

## Key findings

- Significant differences between pseudodata and existing nPDFs for sea quarks and gluons.
- Discrepancies could indicate the presence of saturation effects in future measurements.
- Refitting nPDFs may be insufficient if saturation effects are present, signaling non-linear QCD phenomena.

## Abstract

We analyze the possibility of extracting a clear signal of non-linear parton saturation effects from future measurements of nuclear structure functions at the Electron-Ion Collider (EIC), in the small-x region. Our approach consists in generating pseudodata for electron-gold collisions, using the running-coupling Balitsky-Kovchegov evolution equation, and in assessing the compatibility of these saturate pseudodata with existing sets of nuclear parton distribution functions (nPDFs), extrapolated if necessary. The level of disagreement between the two is quantified by applying a Bayesian reweighting technique. This allows to infer the parton distributions needed in order to describe the pseudodata, which we find quite different from the actual distributions, especially for sea quarks and gluons. This tension suggests that, should saturation effects impact the future nuclear structure function data as predicted, a successful refitting of the nPDFs may not be achievable, which would unambiguously signal the presence of non-linear effects.