Cancellation of Glauber gluon exchange in the double Drell-Yan process

TL;DR

This paper proves that Glauber gluon exchanges cancel out in double Drell-Yan production at all orders, supporting the validity of factorisation in this process and clarifying related issues from single Drell-Yan proofs.

Contribution

It provides a comprehensive all-orders proof of Glauber gluon cancellation in double Drell-Yan, extending factorisation understanding to this process.

Findings

Glauber gluon exchange cancels at all orders in double Drell-Yan.

The cancellation holds for both integrated and differential cross sections.

Clarifies the relation between Glauber cancellation and factorisation in single Drell-Yan.

Abstract

An essential part of any factorisation proof is the demonstration that the exchange of Glauber gluons cancels for the considered observable. We show this cancellation at all orders for double Drell-Yan production (the double parton scattering process in which a pair of electroweak gauge bosons is produced) both for the integrated cross section and for the cross section differential in the transverse boson momenta. In the process of constructing this proof, we also revisit and clarify some issues regarding the Glauber cancellation argument and its relation to the rest of the factorisation proof for the single Drell-Yan process.