A First Account of the Impact of Ion Electromagnetic Dissociation on Event Exclusivity in Ultraperipheral LHC Collisions

In this Letter we explore the modelling of hadron production in electromagnetic ion dissociation (EMD) processes in high-energy ultraperipheral collisions at LHC energies. Since EMD can accompany exclusive particle production in these interactions, we demonstrate that the resulting hadrons can break the exclusivity vetos typically imposed by experiments. As two representative examples, we calculate the impact on existing LHC measurements of exclusive muon pair production ($γγ\toμμ$) and exclusive coherent $J/ψ$ production. We demonstrate that accounting for this effect resolves long-standing tensions between theoretical predictions and experimental measurements.
8 pages, 6 figures