Partonic structure of nuclei from UPCs

Abstract

We present an overview of theoretical and phenomenological studies on the partonic structure of nuclei and small-$x$ QCD dynamics using photon-nucleus $({\hat{I}}^{3}A$) scattering in heavy ion ultraperipheral collisions (UPCs). Focusing on nuclear shadowing, we review implications of coherent charmonium and inclusive dijet production in Pb-Pb UPCs at the LHC and discuss the potential of inelastic ${\hat{I}}^{3}A$ scattering accompanied by forward neutrons in a zero degree calorimeter (ZDC).

10 pages, 4 figures. 2nd International Workshop on the physics of Ultra Peripheral Collisions (UPC 2025)