Double Transverse-Spin Asymmetries for Small-Q_T Drell-Yan Pair Production in p\bar{p} Collisions

TL;DR

This paper analyzes double transverse-spin asymmetries in small transverse momentum Drell-Yan production in proton-antiproton collisions, incorporating all-order gluon resummation to improve theoretical predictions relevant for GSI experiments.

Contribution

It provides the first detailed calculation of all-order gluon resummation effects on double-spin asymmetries in par{p} collisions at small Q_T, highlighting differences from pp collisions.

Findings

Resummation effects are small at GSI kinematics.

Predicted large double-spin asymmetries using recent transversity data.

Resummation reproduces fixed-order QCD corrections upon integration.

Abstract

We discuss the double-spin asymmetries in transversely polarized Drell-Yan process, calculating all-order gluon resummation corrections up to the next-to-leading logarithmic accuracy. This resummation is relevant when the transverse-momentum $Q_T$ of the produced lepton pair is small, and reproduces the (fixed-order) next-to-leading QCD corrections upon integrating over $Q_T$. The resummation corrections in $p\bar{p}$-collision behave differently compared with $pp$-collision cases, and are small at the kinematics in the proposed GSI experiments. This fact allows us to predict large value of the double-spin asymmetries at GSI, using recent empirical information on the transversity.