Estimation of backgrounds with non-prompt leptons in same sign multi-leptonic signatures of the ttH analysis at ATLAS

The study of $ttH$ production at the LHC plays a crucial role in the Higgs physics programme, as it allows a direct test of the Yukawa coupling $y_t$ to the heaviest fermion, and can constrain effects of new physics in the top coupling sector. I will present results on the search for $ttH$ in an inclusive multi-leptonic final state at the ATLAS experiment, from analysis of $pp$ collision data collected during LHC Run II at $\sqrt{s}$ = 13 TeV. Focus will be given to the analysis of final states with high jet multiplicity, and the presence of exactly one pair of electrons and muons with the same electric charge and no hadronically decaying tau leptons. Among the several multi-leptonic channels analysed in ATLAS, these have the highest sensitivity.