Speaker
Description
With the ongoing Run 3 stage of LHC, the couplings of the 125 GeV Higgs are being determined with higher precision. However, within the experimental uncertainty, potential deviations from the SM predictions can be accommodated. Such deviations are realisable in models with multiple Higgs doublets, the NHDMs. These models naturally give rise to flavour changing neutral couplings at tree level, which can be avoided by imposing additional symmetries. For models with more than two doublets, the different ways those symmetries are realised lead to five distinct types of models. We explore the possibility of large pseudoscalar Yukawa couplings in a softly broken $\mathbb{Z}_2 \times \mathbb{Z}_2$ three-Higgs doublet model with explicit CP violation in the scalar sector. We use a Machine Learning black box optimisation algorithm to efficiently search for such a possibility within the 25 different branches of this model, which arise from the 5 different types and mass orderings of the neutral scalar bosons. We identify the model choices that allow a purely pseudoscalar coupling in light of all recent experimental limits, including direct searches for CP-violation, thus motivating increased effort into improving the experimental precision.