Electroweak top-quark pair production at the LHC with Z′ bosons to NLO QCD in POWHEG

We present the calculation of the NLO QCD corrections to the electroweakproduction of top-antitop pairs at the CERN LHC in the presence of a new neutral gaugeboson. The corrections are implemented in the parton shower Monte Carlo programPOWHEG. Standard Model (SM) and new physics interference e ects are properly takeninto account. QED singularities, rst appearing at this order, are consistently subtracted.Numerical results are presented for SM andZ0total cross sections and distributions ininvariant mass, transverse momentum, azimuthal angle and rapidity of the top-quark pair.The remaining theoretical uncertainty from scale and PDF variations is estimated, and thepotential of the charge asymmetry to distinguish between new physics models is investi-gated for the Sequential SM and a leptophobic topcolor model