# Factorisation of soft gluons in multiparton scattering

## TL;DR

This paper demonstrates that soft gluons in multiparton scattering can be decoupled and described by Wilson line vacuum expectation values, extending the factorisation proof from Drell-Yan processes.

## Contribution

It generalizes the factorisation proof for soft gluons in multiparton scattering using nonabelian Ward identities, building on previous Drell-Yan results.

## Key findings

- Soft gluons can be decoupled in multiparton scattering.
- Effects are described by Wilson line vacuum expectation values.
- The proof extends the factorisation framework to more complex processes.

## Abstract

We show that soft gluons exchanged between the two colliding protons in multiparton scattering processes can be decoupled, such that their effects are described by the vacuum expectation values of Wilson lines. Our argument relies on nonabelian Ward identities and generalises the proof of factorisation for single Drell-Yan production given by Collins, Soper and Sterman.