Speaker
Description
The observation of the Higgs boson production in association with a top quark pair (ttH) by ATLAS and CMS in 2018 directly confirmed the existence of the top quark Yukawa coupling. The Standard Model (SM) predicts a CP-even structure to this coupling, but a CP-odd component can arise in models beyond the SM (BSM). Recently, ATLAS and CMS searched for such a component in analyses targetting ttH events in which the Higgs decays to 2 photons. However, the Higgs-photon coupling is loop-induced and could be affected by BSM effects.
We will probe the CP nature of the top-Higgs interaction by analyzing ttH events in the H->bb decay channel, using the full Run-2 data collected by the ATLAS experiment. I will present the analysis strategy for the measurement, the main challenges in modelling signal and background processes and the expected sensitivity for discovery or exclusion of new physics.
