QCD Corrections to Double and Single Spin Asymmetries in Vector Boson Production at Polarized Hadron Colliders

The production of $W^{\pm }$ and $Z^0$ bosons in collisions of longitudinally polarized protons allows to access various combinations of the polarized quark distributions from the study of double and single spin asymmetries. We compute the $\mathcal{O}({\alpha }_s)$ corrections to these asymmetries as function of the vector boson rapidity $y$ in the hadron-hadron centre-of-mass frame. Detailed studies of the numerical impact of the next-to-leading order corrections are presented. The theoretical uncertainties of an extraction of polarized quark distributions from future vector boson production data are investigated in detail.