Monte Carlo event generation of photon-photon collisions at colliders

TL;DR

This paper discusses implementing photon-photon collision simulations in Pythia 8, crucial for understanding backgrounds in future electron-positron colliders, by integrating photon PDFs and modifying the parton-shower algorithm.

Contribution

The paper introduces photon PDFs into Pythia 8 and details modifications to the parton-shower algorithm for photon beams, enhancing simulation accuracy.

Findings

Implementation of photon PDFs in Pythia 8

Modified parton-shower algorithm for photon interactions

Framework for future photon collision studies

Abstract

In addition to being interesting in itself, the photon-photon interactions will be an inevitable background for the future electron-positron colliders. Thus to be able to quantify the potential of future electron-positron colliders it is important to have an accurate description of these collisions. Here we present our ongoing work to implement the photon-photon collisions in the Pythia 8 event generator. First we introduce photon PDFs in general and then discuss in more detail one particular set we have used in our studies. Then we will discuss how the parton-shower algorithm in Pythia 8 is modified in case of photon beams and how the beam remnants are constructed. Finally a brief outlook on future developments is given.