Hard Diffraction in Pythia 8

TL;DR

This paper reviews and introduces models for diffraction in Pythia 8, including a new hard diffraction model based on the Pomeron approach, which incorporates a dynamical gap survival probability.

Contribution

It presents a new hard diffraction model in Pythia 8 that integrates the Pomeron approach with multiparton interactions, enabling more realistic simulations of diffraction.

Findings

Implemented a new hard diffraction model in Pythia 8.

Introduced a dynamical rapidity gap survival probability.

Enhanced the simulation of diffraction processes.

Abstract

We present an overview of the options for diffraction implemented in the general--purpose event generator Pythia 8. We review the existing model for low-- and high--mass soft diffraction and present a new model for hard diffraction in pp and ppbar collisions. Both models uses the Pomeron approach pioneered by Ingelman and Schlein, factorising the single diffractive cross section into a Pomeron flux and a Pomeron PDF. The model for hard diffraction is implemented as a part of the multiparton interactions framework, thereby introducing a dynamical rapidity gap survival probability that explicitly breaks factorisation.