Twist expansion of differential cross-sections of forward Drell-Yan process

TL;DR

This paper investigates higher twist effects in the forward Drell-Yan process at the LHC using the GBW saturation model, revealing the breaking of the Lam-Tung relation at twist 4 and paving the way for future analyses of multiple scattering.

Contribution

It introduces a twist expansion of Drell-Yan structure functions within the GBW saturation model, highlighting higher twist effects and the violation of the Lam-Tung relation at twist 4.

Findings

Lam-Tung relation is broken at twist 4

Saturation scale acts as the hadronic scale in OPE

Provides a framework for analyzing multiple scattering effects

Abstract

Forward Drell-Yan process at the LHC is a sensitive tool for investigating higher twist effects in QCD. The expansion of all Drell-Yan structure functions is performed assuming GBW saturation model and the saturation scale plays the role of the hadronic scale of OPE. We show that the Lam-Tung relation is broken at twist 4. The results open the way for a forthcoming analysis of multiple scattering and higher twist effects.