Forward Z-boson production and the unintegrated sea quark density

TL;DR

This paper introduces a new factorization approach for forward Z-boson production at the LHC, accounting for non-collinear QCD radiation effects through unintegrated sea quark densities, impacting the vector boson spectrum.

Contribution

It proposes a novel factorization formula incorporating unintegrated sea quark densities to better describe forward Drell-Yan processes at high energies.

Findings

Numerical analysis of the formula shows significant kinematic effects from initial-state transverse momentum.

The approach improves understanding of QCD radiation effects in forward Z-boson production.

The method highlights the importance of unintegrated parton distributions in collider phenomenology.

Abstract

Drell-Yan production in the forward region at the Large Hadron Collider is sensitive to multiple radiation of QCD partons not collinearly ordered, emitted over large rapidity intervals. We propose a method to take account of these radiative contributions via a factorization formula which depends on the unintegrated, or transverse momentum dependent, splitting function associated with the evolution of the initial-state sea quark distribution. We analyze this formula numerically, and point out kinematic effects from the initial-state transverse momentum on the vector boson spectrum.