# A Monte-Carlo Simulation of Double Parton Scattering

## TL;DR

This paper introduces a new Monte-Carlo simulation for double parton scattering that incorporates recent QCD developments, including parton splittings and impact-parameter dependence, providing more detailed modeling of DPS processes at the LHC.

## Contribution

It presents a novel Monte-Carlo simulation framework for DPS based on a recent QCD approach, including parton splittings and impact-parameter effects, improving upon existing models.

## Key findings

- Differences observed in several distributions compared to existing DPS models.
- The simulation captures the dynamics of $1 o2$ perturbative splittings.
- Impact-parameter dependence influences DPS predictions.

## Abstract

In this work, a new Monte-Carlo simulation of double parton scattering (DPS) at parton level is presented. The simulation is based on the QCD framework developed recently by M. Diehl, J. R. Gaunt and K. Sch\"{o}nwald. With this framework, the dynamics of the $1\to2$ perturbative splittings is consistently included inside the simulation, with the impact-parameter dependence taken into account. The simulation evolves simultaneously two hard systems from a common hard scale down to the hadronic scale. The evolution is performed using an angular-ordered parton shower which is combined with a set of double parton distributions that depend explicitly on the inter-parton distance. An illustrative study is performed in the context of same-sign WW production at the LHC, with the quark content of the proton being limited to three flavours. In several distributions we see differences compared to DPS models in Herwig, Pythia, and the DPS "pocket formula".