Drell-Yan non-singlet spin cross sections and spin asymmetry to O(αs2) (II) Original Research Article

We present predictions for the non-singlet Drell-Yan longitudinal spin cross sections and spin asymmetry, ALL, in proton-proton collisions at large pT at the RHIC energy of 200 GeV at next-to-leading order QCD. The higher order corrections to the non-singlet polarized cross section, σNSLL, are sizeable and similar to those found for the unpolarized cross section. The non-singlet asymmetry parameter, ALLNS, is very stable against higher order corrections and is a direct measurement of the non-singlet (i.e., valence) polarized quark distributions within the proton.