Cancellation mechanism for the electron electric dipole moment connected with the baryon asymmetry of the Universe

Understand

We elucidate a cancellation mechanism for the electric dipole moment of the electron in the general two Higgs doublet model.

• The impressive improvement by the ACME Collaboration in 2018 suggests the presence of a new electron Yukawa coupling that brings in exquisite cancellations among dangerous diagrams, broadening the solution space for electroweak baryogenesis driven by an extra top Yukawa coupling.
• The cancellation mechanism calls for the new Yukawa couplings to have hierarchical structures that echo the observed pattern of the Standard Model Yukawa couplings.