Soft gluon resummation in Drell-Yan dilepton production at small transverse momentum: spin asymmetry and a novel asymptotic formula

TL;DR

This paper investigates the soft gluon corrections in transversely polarized Drell-Yan processes at small transverse momentum, showing cancellations in spin asymmetry and introducing a new asymptotic formula to extract transversity distributions from experimental data.

Contribution

It presents a comprehensive resummation of soft gluon effects at next-to-leading logarithmic accuracy and introduces a novel asymptotic formula for analyzing spin asymmetries.

Findings

Soft gluon corrections largely cancel in the spin asymmetry.

The asymmetries are calculated for various collider scenarios.

A new asymptotic formula aids in extracting transversity distributions.

Abstract

We discuss the double-spin asymmetry \aqt in the transversely polarized Drell-Yan process at small transverse-momentum Q_T of the produced dilepton. The soft gluon corrections relevant for small Q_T are resummed to all orders in \alpha_s, up to the next-to-leading logarithmic accuracy. We show that the soft gluon corrections largely cancel in the spin asymmetry, but the significant corrections still remain.The asymmetries \aqt are calculated for pp collision at RHIC and J-PARC, and for p\bar{p} collision at GSI. A novel asymptotic formula for \aqt at small Q_T is presented, which provides a new approach to extract the transversity \delta q(x) from the experimental data.