Spontaneous CP breaking in $S_3$ flavored Higgs sector with soft-breaking terms

Abstract

We analyze the Higgs sector of the minimal $S_3$-invariant extension of the Standard Model including spontaneous and explicit CP violation arising from the spontaneous electroweak symmetry breaking. This extended Higgs sector includes three SU(2) Higgs doublets with and without complex vev's, which ones providing an interesting scenario to analyze the Higgs masses spectrum, trilinear Higgs self-couplings and CP violation. We present how the spontaneous electroweak symmetry breaking coming from three SU(2) Higgs doublets gives an interesting scenario when spontaneous CP violation arises from the Higgs doublet $Φ_S$, singlet under $S_3$. Furthermore, a numerical analysis of the Higgs masses and trilinear Higgs self-couplings is presented. Particularly, we find a physical solution for the scenario in which spontaneous CP break is provided by $Φ_S$. The analysis of soft breaking to $S_3$ symmetry including CP breaking terms opens up a rich parameter space, with Higgs masses and trilinear Higgs self-couplings favoring one of the Higgs bosons as a SM-like type Higgs boson.