Photo-nuclear collisions in Pythia 8

Abstract

We present the recent developments in simulations of ultra-peripheral collisions with the PYTHIA Monte Carlo event generator. We first introducte the simulation framework and the discuss about available photon fluxes. Then we review the status of recent comparisons and tuning efforts to HERA photoproduction data which provide the baseline of photon-nucleon interactions. Then we present the vector-meson-dominance (VMD) based approach to model interactions between a real photon and a nucleus target applying the Angantyr model which provides a framework for simulate heavy-ion collisions in Pythia. We present predictions for inclusive UPC observables, including charged-particle production and heavy-flavour mesons in kinematics similar to the preliminary measurements.