Speaker
Description
In this talk I present NLO QCD predictions for the $$pp\to t\bar{t}t\bar{t}+X$$ process in the 4 lepton decay channel at the integrated and differential level for the LHC centre-of-mass energy of $$\sqrt{s}=13.6$$ TeV. Specifically I compare the fixed order NLO QCD calculations to the parton-shower matched results obtained with MC@NLO and POWHEG matching. In the former, NLO QCD corrections are consistently included in the production and decay of the four top quarks, preserving all spin correlations. In the latter, higher order effects in top-quark decays with approximate spin correlations are simulated in the parton showers, using Pythia. Additionally I analyse the impact of including matrix element corrections in the top quark decays in the parton-shower matched predictions.