Helicity Parton Distributions from Spin Asymmetries in W-Boson Production at RHIC

TL;DR

This paper provides a next-to-leading order QCD calculation of spin asymmetries in W-boson production at RHIC, aiding the global analysis of helicity parton distributions.

Contribution

It introduces a Monte Carlo program for calculating spin asymmetries and demonstrates its use in a toy analysis of polarized anti-quark distributions.

Findings

The calculation accurately models spin asymmetries in W production.

Anticipated RHIC data can significantly improve knowledge of polarized anti-quark distributions.

The Monte Carlo tool facilitates inclusion of experimental data in global analyses.

Abstract

We present a next-to-leading order QCD calculation of the cross section and longitudinal spin asymmetry in single-inclusive charged-lepton production, pp -> l X, at RHIC, where the lepton is produced in the decay of an electroweak gauge boson. Our calculation is presented in terms of a multi-purpose Monte-Carlo integration program that may be readily used to include experimental spin asymmetry data in a global analysis of helicity parton densities. We perform a toy global analysis, studying the impact of anticipated RHIC data on our knowledge about the polarized anti-quark distributions.