Speaker
Description
We present a systematic study of large CP violation in the Complex Two-Higgs-Doublet Model with softly broken $Z_2$ symmetry, based on global scans of Type-I and Type-II realizations including theoretical consistency, collider data, and the stringent electron EDM constraint. We identify two qualitatively different CP-violating regimes: in Type-I, sizable gauge-sector CP violation is possible only in a near-degenerate Higgs scenario where the 125 GeV state is accompanied by a second neutral scalar, and the entire viable parameter space predicts a nonzero lower bound on the eEDM within reach of upcoming experiments; in contrast, Type-II suppresses gauge-sector CP violation but allows near-maximal CP mixing in the Yukawa sector of the heavy neutral Higgs bosons. We further uncover a phenomenon of hidden CP violation in the Higgs alignment limit, where heavy neutral scalars retain large intrinsic CP mixing despite vanishing gauge couplings, and show that this can be probed through cubic interactions involving the charged Higgs boson.