The Impact of NLO-Corrections on the Determination of the $\bar{u},\bar{d} Content of Nucleons from Drell-Yan Production

Abstract

The interpretation of Drell-Yan production in terms of the antiquark densities depends on NLO corrections. Besides the NLO corrections to the familiar annihilation $q\bar{q}\to {\gamma }^{\ast }\to l^{+}{l}^{-}$, there is a substantial contribution from the QCD Compton subprocesses $gq\to q{\gamma }^{\ast }\to q{l}^{+}{l}^{-}$ and $g\bar{q}\to q{\gamma }^{\ast }\to q{l}^{+}{l}^{-}$. The beam and target dependence of the two classes of corrections is different. We discuss the impact of this difference on the determination of the $\bar{d}-\bar{u}$ asymmetry in the proton from the comparison of the $pp$ and $pn$ Drell-Yan production.

Comments: 4 pages, 1 eps-figure. To be published in Proceedings of DIS'98