Single transverse spin asymmetries in inclusive hadron production

TL;DR

This paper develops a phenomenological model for transverse single spin asymmetries in inclusive hadron production, extending QCD factorization to include quark intrinsic motion and new spin-dependent functions, with data fitting and predictions.

Contribution

It introduces a generalized QCD factorization approach incorporating quark intrinsic motion and new spin-dependent functions for asymmetry calculations.

Findings

Fitted parameters to p(transv. polarized) + p -> pion data.

Predicted asymmetries for l + p(transv. polarized) -> pion and gamma^* + p processes.

Demonstrated the model's consistency with experimental observations.

Abstract

A consistent phenomenological approach to the computation of transverse single spin asymmetries in inclusive hadron production is presented, based on the assumed generalization of the QCD factorization theorem to the case in which quark intrinsic motion is taken into account. New k_T and spin dependent quark distribution and fragmentation functions are considered: some of them are fixed by fitting data on p(transv. polarized) + p -> pion + X and predictions are given for single spin asymmetries in l + p(transv. polarized) -> pion + X and gamma^* + p(transv. polarized) -> pion + X processes.