The Sivers single-spin asymmetry in photon-jet production
Abstract
We study a weighted asymmetry in the azimuthal distribution of photon-jet pairs produced in the process p^\uparrow p --> \gamma jet X with a transversely polarized proton. We focus on the contribution of the Sivers effect only, considering experimental configurations accessible at RHIC-BNL. We show that predictions for the asymmetry, obtained in terms of gluonic-pole cross sections calculable in perturbative QCD, can be tested and clearly discriminated from those based on a generalized parton model, involving standard partonic cross sections. Experimental measurements of the asymmetry will therefore test our present understanding of single-spin asymmetries.
Keywords
Cite
@article{arxiv.hep-ph/0703153,
title = {The Sivers single-spin asymmetry in photon-jet production},
author = {Alessandro Bacchetta and Cedran Bomhof and Umberto D'Alesio and P. J. Mulders and F. Murgia},
journal= {arXiv preprint arXiv:hep-ph/0703153},
year = {2008}
}
Comments
Some changes in the text and in the layout. Two references added. Accepted for publication in PRL