Improved modeling of photon-photon processes in ultraperipheral collisions at hadron colliders

The CERN LHC is not only the current energy-frontier collider for parton-parton collisions, but has proven a powerful photon collider providing photon-photon (\(\gamma\gamma\)) collisions at center-of-mass energies and luminosities never reached before. The latest theoretical developments implemented in the gammaUPC Monte Carlo (MC) event generator, which can calculate arbitrary exclusive final state produced via \(\gamma\gamma\) fusion in ultraperipheral collisions (UPCs) of protons and/or nuclei at the LHC, are presented. These include azimuthal modulations of dilepton pairs produced in the \(\gamma\gamma\ \rightarrow\ \ell^{+}\ell^{-}\) process, and neutron emission probabilities for photoexcited lead ions in PbPb UPCs. A few comparisons of the results of the updated gamma-UPC v.1.6 code to relevant RHIC and LHC data are presented.