Transverse-momentum resummation for boson plus jet production at hadron colliders.

We consider the associated production of a vector or Higgs boson with a jet in hadronic collisions. When the transverse momentum of the boson-jet system is much smaller than its invariant mass , the QCD perturbative expansion is affected by large logarithmic terms that must be resummed to all orders. We discuss the all-order resummation structure of the logarithmically enhanced contributions up to next-to-leading logarithmic accuracy. Resummation is performed at the differential level with respect to the kinematical variables of the boson-jet system. Soft-parton radiation produces azimuthal correlations that are fully accounted for in our framework. We present explicit analytical results for the resummation coefficients up to next-to-leading order and next-to-leading logarithmic accuracy, that include the exact dependence on the jet radius.