Alignment, reverse alignment, and wrong sign Yukawa couplings in two Higgs doublet models

摘要

We consider two Higgs doublet models with a softly broken U(1) symmetry, forvarious limiting values of the scalar mixing angles $\alpha$ and $\beta$. Thesecorrespond to the Standard Model Higgs particle being the lighter CP-evenscalar (alignment) or the heavier CP-even scalar (reverse alignment), and alsothe limit in which some of the Yukawa couplings of this particle are of theopposite sign from the vector boson couplings (wrong sign). In these limits weimpose a criterion for naturalness by demanding that quadratic divergencescancel at one loop. We plot the allowed masses of the remaining physicalscalars based on naturalness, stability, perturbative unitarity and constraintscoming from the $\rho$ parameter. We also calculate the $h\to \gamma\gamma$decay rate in the wrong sign limit.