Transverse-momentum resummation for vector-boson pair production at NNLL plus NNLO

We consider the transverse-momentum (pT) distribution of Z Z and W+W- boson pairs produced in hadron collisions. At small pT, the logarithmically enhanced contributions due to multiple soft-gluon emission are resummed to all orders in QCD perturbation theory. At intermediate and large values of pT, we consistently combine resummation with the known fixed-order results. We exploit the most advanced perturbative information that is available at present: next-to-next-to-leading logarithmic resummation combined with the next-to-next-to-leading fixed-order calculation. After integration over pT, we recover the known next-to-next-to-leading order result for the inclusive cross section. We present numerical results at the LHC, together with an estimate of the corresponding uncertainties. We also study the rapidity dependence of the pT spectrum and we consider pT efficiencies at different orders of resummed and fixed-order perturbation theory.