Correlating A→γ γ with electric dipole moments in the two Higgs doublet model in light of the diphoton excesses at 95 GeV and 152 GeV

We examine the correlations between new scalar boson decays to photons and electric dipole moments (EDMs) in the CP-violating flavor-aligned two-Higgs-doublet model (2HDM). It is convenient to work in the Higgs basis {H1,H2} where only the first Higgs doublet field H1 acquires a vacuum expectation value. In light of the LHC Higgs data, which agree well with Standard Model (SM) predictions, it follows that the parameters of the 2HDM are consistent with the Higgs alignment limit. In this parameter regime, the observed SM-like Higgs boson resides almost entirely in H1, and the other two physical neutral scalars, which reside almost entirely in H2, are approximate eigenstates of CP (denoted by the CP-even H and the CP-odd A). In the Higgs basis, the scalar potential term Z¯7H1†H2H2†H2+H.c. governs the charged-Higgs loop contributions to the decay of H and A to photons. If ReZ¯7ImZ¯7≠0, then CP-violating effects are present and allow for an H+H−A coupling, which can yield a sizable branching ratio for A→γγ. These CP-violating effects also generate nonzero EDMs for the electron, the neutron and the proton. We examine these correlations for the cases of mA=95 GeV and mA=152 GeV where interesting excesses in the diphoton spectrum have been observed at the LHC. These excesses can be explained via the decay of A while being consistent with the experimental bound for the electron EDM in regions of parameter space that can be tested with future neutron and proton EDM measurements. This allows for the interesting possibility where the 95 GeV diphoton excess can be identified with A, while mH≃98 GeV can account for the best fit to the LEP excess in e+e−→ZH with H→bb¯.