Electric dipole moments in two-Higgs-doublet models

Abstract

Electric dipole moments are extremely sensitive probes for additional sources of CP violation in new physics models. Specifically, they have been argued in the past to exclude new CP-violating phases in two-Higgs-doublet models. Since recently models including such phases have been discussed widely, we revisit the available constraints in the presence of mechanisms which are typically invoked to evade flavour-changing neutral currents. To that aim, we start by assessing the necessary calculations on the hadronic, nuclear and atomic/molecular level, deriving expressions with conservative error estimates. Their phenomenological analysis in the context of two-Higgs-doublet models yields strong constraints, in some cases weakened by a cancellation mechanism among contributions from neutral scalars. While the corresponding parameter combinations do not yet have to be unnaturally small, the constraints are likely to preclude large effects in other CPviolating observables. Nevertheless, the generically expected contributions to electric dipole moments in this class of models lie within the projected sensitivity of the next-generation experiments.

h → Zγ in the complex two Higgs doublet model

“…Ref. [48] shows that the same happens in the decoupling regime. The same argument holds, of course, for the down type quarks and the charged leptons.…”

“…The recent announcement by the ACME Collaboration [45] of improved bounds on the the electron EDM from their experiment with the ThO molecule has spurred renewed interest in the subject. Several analysis of EDM constraints in the 2HDM have appeared in the last few years [46][47][48], including two concerning specifically the C2HDM discussed in this article [49,50]. Although using mainly specific choices for most parameters, ref.…”

“…The same argument holds, of course, for the down type quarks and the charged leptons. As a result, one cannot assume dominance of the lightest scalar [48,50]. In the C2HDM, CP violation in the charge Higgs interactions arises only from the CKM matrix.…”

Direct and indirect constraints on CP-violating Higgs-quark and Higgs-gluon interactions

“…(2.4). The Yukawa interactions contribute to the (C)EDMs [39][40][41][42] and the Weinberg operator [32,43] through Barr-Zee diagrams, shown in figure 1. The quark (C)EDMs receive additional contributions from the one-loop diagrams shown in figure 2 [44].…”

CP violating Two-Higgs-Doublet Model: constraints and LHC predictions

“…Charged Higgs phenomenology in CPV 2HDMs has been considered in [17,[19][20][21][22][23]. Surviving regions of the parameter space passing all experimental constraints in CPV 2HDMs have been studied in [24][25][26][27][28] and in [29] with a focus on EW Baryogenesis. Search signals for explicit CPV have been suggested for Z 2 symmetric 2HDMs in [30,31] and for the general 2HDM in [32].…”