Simulation of on- and off-shell $t\bar{t}$ production with the Monte Carlo generator bb4l at CMS

Abstract

Top quark pair production processes at the LHC are important for precision measurements of observables such as the top quark mass or top quark pair spin correlations and as a background for BSM searches. As such, it is crucial that MC simulation of this process is available for experimental analyses at the highest level of precision possible. Here, we show an investigation of the NLO MC generator bb4l interfaced to Pythia 8 for parton showering. This program not only models top quark pair production, but also single top quark production in association with a W boson, as well as their interference, and correctly takes into account effects from the finite top width. We compare it to the current simulations using the hvq generator, with possible implications for future top mass measurements