Matrix element corrections in top quark decays for the ttW^± process

We present a method that allows enabling matrix element corrections (MECs) in Pythia8 with MC@NLO matching, without incurring double counting. MECs are an interesting feature that may contribute to the accuracy of theoretical predictions, alongside matching and merging. We directly compare our method to a specific choice of settings in Pythia8, which can remove double-counting for MECs in certain processes. We show results by taking the ttW process as an example. This choice allows us to study the impact of decay MECs in the 2SSℓ and 3ℓ final states. We find that jet-related observables receive these corrections unevenly throughout the phase space. They can contribute up to ± 6% in certain regions.