Automated higher-order predictions for ultra-peripheral collisions with full impact-parameter dependence

Abstract

We present an automated framework within the Sherpa event generator for the simulation of photon-induced processes in high-energy collisions of protons and nuclei. The calculation builds upon the equivalent-photon approximation and incorporates different form factor parametrisations, taking into account the full dependence on the finite size of emitters and their impact parameter. Higher-order effects are taken into account automatically by either YFS-resummation of soft photon emissions to all orders or Next-to-Leading Order in electroweak theory. We validate our simulation framework using data from two representative ATLAS measurements of exclusive $μ$-pair production in $pp$ and Pb+Pb collisions. Exemplary predictions for exclusive $W$-pair production in $pp$ collisions and $τ$-pair production in both $pp$ and Pb+Pb collisions are presented.