Ingo Schienbein (Universite Joseph Fourier/LPSC): The talk will consist of three parts. In the first part, we introduce the general class of G(221) models based on an SU(2)xSU(2)xU(1) gauge symmetry predicting the existence of heavy charged and neutral gauge bosons called W' and Z'. We discuss how to address the so called  inverse problem to identify the correct theory in the case of a discovery of a W' and/or Z' boson by correlating suitable observables. In the second part we focus on Z' and W' resonances in di-lepton final states and extract improved mass limits using a calculation which includes terms at NLO+NLL accuracy. In the third part we present predictions for the electroweak production of top-quark pairs at the LHC in the presence of a new neutral gauge boson based on our new calculation which includes the NLO QCD corrections implemented in the parton shower program POWHEG. The interference effects of Standard Model and New Physics contributions are properly taken into account and the QED singularities, first appearing at this order, are consistently subtracted.  We show numerical results for SM and Z' total cross sections and various distributions. The remaining theoretical uncertainty from scale and PDF variations is estimated and we compare results obtained using the PYTHIA 8 and HERWIG 6 parton shower Monte Carlos. The potential of the charge asymmetry to distinguish between new physics models is investigated for the Sequential SM and a leptophobic topcolor model.

DATA: 30-06-2016