Cancellation of Glauber Gluon Exchange in the Double Drell–Yan Process

Markus Diehl,Jonathan R Gaunt,Peter Plößl,Daniel Ostermeier,Andreas Schäfer

doi:10.1007/s00601-016-1094-0

Abstract

For any factorisation proof, a crucial step is a demonstration of the cancellation of so-called Glauber gluons. We summarise a recent paper in which we demonstrated this cancellation 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 boson transverse momenta.

Highlights

In order to make predictions at the LHC one relies on factorisation formulae that separate the short distance/high-scale dynamics of interest from the low-scale nonperturbative physics
Factorisation has been rigorously proven for Drell–Yan production, for the total cross section and cross section differential in the pT of the colour singlet system [8,12,13,14]
For the analogous process in double parton scattering, namely double Drell–Yan production, a factorisation formula was written down long ago for the total cross section [21,22] based on the analysis of the lowest-order Feynman diagrams

Summary

Introduction

In order to make predictions at the LHC one relies on factorisation formulae that separate the short distance/high-scale dynamics of interest from the low-scale nonperturbative physics. Factorisation has been rigorously proven for Drell–Yan production (or, more generally, colour-singlet production), for the total cross section and cross section differential in the pT of the colour singlet system [8,12,13,14]. These factorisation formulae are correct at leading power—i.e. up to corrections of order Λ2QC D/Q2, with Q the hard scale of the process. Serious attempts to rigorously justify these formulae have only begun in recent years [7,15,16,20]

Schäfer E-mail

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