Transverse single spin asymmetries in Drell-Yan processes
Abstract
Recently, it has been shown, contrary to previous beliefs, that the k_T distribution of quarks in a transversely polarized proton can be asymmetric. This ``Sivers effect'' had already been used to explain transverse single spin asymmetries (SSA) observed in inclusive pion production, p(transv. polarized) p --> pion + X and p-bar(transv. polarized) p --> pion + X. In such channels, however, other mechanisms, like the ``Collins effect'' (a k_T asymmetric fragmentation of a transversely polarized quark into pions), may generate SSA. The Sivers asymmetry is used here to compute SSA in Drell-Yan processes; in this case, by considering the differential cross-section in the lepton-pair invariant mass, rapidity and transverse momentum, other mechanisms which may originate SSA cannot contribute. Estimates for RHIC experiments are given.
Keywords
Cite
@article{arxiv.hep-ph/0210371,
title = {Transverse single spin asymmetries in Drell-Yan processes},
author = {M. Anselmino and U. D'Alesio and F. Murgia},
journal= {arXiv preprint arXiv:hep-ph/0210371},
year = {2009}
}
Comments
LaTeX, 24+1 pages, 7 ps figures, uses epsfig.sty