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

TL;DR

This paper investigates how ion electromagnetic dissociation affects event exclusivity in ultraperipheral LHC collisions, revealing its role in resolving discrepancies between theory and experiment.

Contribution

It models the impact of electromagnetic ion dissociation on hadron production and demonstrates its significance in interpreting LHC measurements.

Findings

Electromagnetic ion dissociation can break event exclusivity in ultraperipheral collisions.

Accounting for EMD effects resolves longstanding tensions between theory and experimental data.

The study provides a framework for including EMD in modeling hadron production.

Abstract

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 ($\gamma\gamma\to\mu\mu$) and exclusive coherent $J/\psi$ production. We demonstrate that accounting for this effect resolves long-standing tensions between theoretical predictions and experimental measurements.