Double Transverse-Spin Asymmetries in Drell-Yan Processes with Antiprotons

Abstract

We present next-to-leading order predictions for double transverse-spin asymmetries in Drell--Yan dilepton production initiated by proton--antiproton scattering. The kinematic region of the proposed PAX experiment at GSI: $30\lesssim s\lesssim 200{\text{GeV}}^2$ and $2\lesssim M\lesssim 7\text{GeV}$ is examined. The Drell--Yan asymmetries turn out to be large, in the range 20--40%. Measuring these asymmetries would provide the cleanest determination of the quark transversity distributions.

Comments: 11 pages, 7 figures, uses elsart and feynmp (included); one new reference added