Comparisons of the Monte Carlo programs HORACE and WINHAC for   single-W-boson production at hadron colliders
  We present the comparisons of two independent Monte Carlo event generators, HORACE and WINHAC, for single-W-boson production in hadronic collisions with multiphoton effects in leptonic W decays. These comparisons were performed first at the parton level with fixed quark-beams energy, and then at the hadron level for proton-proton collisions at the LHC. In general, a good agreement between the two programs has been found. Possible sources of differences in some of the presented results are discussed. We also present and discuss the effects of including non-zero quark masses for the main single-W-boson observables at the LHC. 
C. M. Carloni Calame, S. Jadach, G. Montagna, O. Nicrosini and W.   Placzek