Vector boson production at hadron colliders: transverse-momentum resummation and leptonic decay

We consider the transverse-momentum (q T) distribution of Drell-Yan lepton pairs produced, via W and Z/γ * decay, in hadronic collisions. At small values of q T, we resum the logarithmically-enhanced perturbative QCD contributions up to next-to-next-to-leading logarithmic accuracy. Resummed results are consistently combined with the known O (S²) fixed-order results at intermediate and large values of q T. Our calculation includes the leptonic decay of the vector boson with the corresponding spin correlations, the finite-width effects and the full dependence on the final-state lepton (s) kinematics. The computation is encoded in the numerical program DYRes, which allows the user to apply arbitrary kinematical cuts on the final-state leptons and to compute the corresponding distributions in the form of bin histograms. We present a comparison of our results with some of the available LHC data. The inclusion of the leptonic decay in the resummed calculation requires a theoretical discussion on the q T recoil due to the transverse momentum of the produced vector boson. We present a q T recoil procedure that is directly applicable to q T resummed calculations for generic production processes of high-mass systems in hadron collisions.