Photoproduction of diffractive dijets in Pythia 8

TL;DR

This paper introduces a new simulation framework in Pythia 8 for modeling hard diffractive events in photoproduction, incorporating rapidity gap survival probabilities to explain observed factorization-breaking effects.

Contribution

It extends the Pythia 8 model for proton-proton collisions to photoproduction, providing a unified approach to simulate diffractive dijet production with realistic gap survival effects.

Findings

Generated cross sections agree with HERA data

Predictions for electron-ion colliders are provided

Factorization-breaking effects are more pronounced in ultra-peripheral LHC collisions

Abstract

The new framework for the simulations of hard diffractive events in photoproduction within Pythia 8 is presented. The model, originally introduced for proton-proton collisions, applies the dynamical rapidity gap survival probability based on the multiparton interaction model in Pythia. These additional interactions provide a natural explanation for the observed factorization-breaking effects in hard diffraction by filling up the rapidity gaps used to classify the events of diffractive origin. The generated cross sections are well in line with the existing data from HERA experiments and predictions for the future electron-ion collider are presented. In addition, also predictions for ultra-peripheral collisions at the LHC have been calculated where the factorization-breaking effects are found to be more pronounced.