One-loop weak corrections to hadronic production of Z bosons at large transverse momenta Original Research Article

To match the precision of present and future measurements of Z-boson production at hadron colliders, electroweak radiative corrections must be included in the theory predictions. In this paper we consider their effect on the transverse momentum (image) distribution of Z bosons, with emphasis on large image. We evaluate, analytically and numerically, the full one-loop corrections for the parton scattering reaction image and its crossed variants. In addition we derive compact approximate expressions which are valid in the high-energy region, where the weak corrections are strongly enhanced by logarithms of image. These expressions include quadratic and single logarithms as well as those terms that are not logarithmically enhanced. This approximation, which confirms and extends earlier results obtained to next-to-leading logarithmic accuracy, permits to reproduce the exact one-loop corrections with high precision. Numerical results are presented for proton–proton and proton–antiproton collisions. The corrections are negative and their size increases with image. For the Tevatron they amount up to −7% at 300 GeV. For the LHC, where transverse momenta of 2 TeV or more can be reached, corrections up to −40% are observed. We also include the dominant two-loop effects of up to 8% in our final LHC predictions.