Inclusion of W^+- single-spin asymmetry data in a polarised PDF determination via Bayesian reweighting

TL;DR

This paper demonstrates how to incorporate W^+- single-spin asymmetry data from polarized proton collisions into polarized parton distribution functions using Bayesian reweighting, enhancing the accuracy of these distributions.

Contribution

It introduces a Bayesian reweighting method to update polarized PDFs with new W^+- asymmetry data, integrating experimental results into existing PDF ensembles.

Findings

Bayesian reweighting effectively updates polarized PDFs with new data.

Inclusion of W^+- asymmetry data improves the constraints on polarized quark distributions.

Future measurements at RHIC can further refine polarized PDFs.

Abstract

We discuss how the experimental information from longitudinal single-spin asymmetries for $W^{\pm}$ boson production in polarised proton-proton collisions can be included in a polarised parton determination by Bayesian reweighting of a Monte Carlo set of polarised PDF replicas. We explicitly construct a prior ensemble of polarised parton distributions using available fits to inclusive and semi-inclusive DIS data and we discuss the potential impact of existing and future RHIC measurements on it.