Understand
The contributions of a second Higgs doublet to the electron electric dipole moment near the heavy Higgs decoupling limit are determined within an effective field theory framework.
- In models that satisfy the Glashow-Weinberg condition, the leading contributions in this limit at effective dimension six are shown to come from two-loop Barr-Zee diagrams that include the Standard Model-like Higgs boson.
- Additional diagrams that include heavy Higgs bosons are sub-leading and contribute only at effective dimension eight near the decoupling limit.
- This simplification implies that to leading order in this limit, contributions of a second Higgs doublet to the electron electric dipole moment can be couched entirely in terms of the ratio of Higgs doublet expectation values and a single universal phase appearing in the effective couplings of the Standard Model-like Higgs boson to fermions, without direct reference to the heavy Higgs boson masses or couplings.