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 ≲ s ≲ 200 GeV 2 and 2 ≲ M ≲ 7 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.