W and Z production at next-to-leading order: From large qT to small

CDF is just completing its analysis of the transverse momentum distribution of singly produced W's or Z's. It is important to have the best possible theoretical predictions to compare against experiment across the entire range of transverse momentum qT. Previously, theoretical predictions to next-to-leading order in αs have been restricted to the low-qT and high-qT limits. We take the O(αs2) result at large qT, the corresponding soft gluon resummation at low qT, and consistently match them to obtain a result valid to next-to-leading order at all qT. We present numerical results for W and Z production at √s=630 GeV and 1.8 TeV. Our analysis also provides a new and independent theoretical test of the formalism of resummation in Drell-Yan processes. (orig.)