Experimental overview on UPC results from ALICE

Authors

DOI:

https://doi.org/10.17161/wrvgtb51

Keywords:

photoproduction, UPC, nuclear shadowing, saturation

Abstract

The ALICE Collaboration has extensively studied neutron and proton emission in various electromagnetic dissociation classes of Pb ions, coherent and incoherent $J/\psi$ photoproduction, as well as coherent $\rho^0$ photoproduction using the Run 2 data set, including results from 
the $|t|$-dependence of (in)coherent $J/\psi$. These measurements, which studied exclusive charmonia photoproduction as a function of e.g. energy, Bjorken-$x$, rapidity, and neutron emission, provide unique insights into the initial state of protons and ions, with great sensitivity for both gluon saturation and shadowing. The ALICE Collaboration has also carried out various measurements of different final state systems, such as exclusive four pion photoproduction as well as the measurement of the impact-parameter dependence of coherent production. 
Run 3 data opened a new area for inclusive measurements in UPCs, where $\pi$, $K^{\pm}$, $K^0_S$, $D^0$ meson and $p$, $\Lambda$ baryon fully corrected spectra are extensively studied. On top of that, rare processes like $\tau$ pair production are shown.
Finally, the prospects for these and new measurements using the Run 3 and Run 4 data are discussed.

Downloads

Published

2026-09-09