# Low-$x$ Physics in $pA$ Collisions and at the EIC

## TL;DR

This paper reviews insights gained from $pA$ collisions at RHIC and LHC regarding low-$x$ physics and discusses how future EIC measurements will enhance understanding of gluon saturation and the internal structure of protons and nuclei.

## Contribution

It highlights the complementary roles of $pA$ collisions and EIC in advancing low-$x$ physics and visualizing nuclear structure with high precision.

## Key findings

- EIC will provide detailed multi-dimensional imaging of proton and nucleus structure.
- $pA$ collisions have contributed significantly to understanding gluon saturation.
- Future measurements at EIC will deepen insights into low-$x$ phenomena.

## Abstract

In this proceeding, I review what we have learned, and what we will be able to learn, about low-$x$ physics from proton-nucleus ($pA$) collisions at RHIC and the LHC, and how this complements future Electron-Ion Collider (EIC) measurements. EIC not only will provide us essential and complementary information about the gluon saturation to the knowledge that we have learned from $pA$ collisions at RHIC and the LHC, it will also allow us to visualize the internal structure of protons and nuclei in a multi-dimensional fashion with unprecedented precision.