Electron/muon specific two Higgs doublet model

Abstract

We discuss two Higgs doublet models with a softly-broken discrete S3 symmetry, where the mass matrix for charged-leptons is predicted as the diagonal form in the weak eigenbasis of lepton fields. Similarly to an introduction of Z2 symmetry, the tree level flavor changing neutral current can be forbidden by imposing the S3 symmetry to the model. Under the S3 symmetry, there are four types of Yukawa interactions depending on the S3 charge assignment to right-handed fermions. We find that extra Higgs bosons can be muon and electron specific in one of four types of the Yukawa interaction. This property does not appear in any other two Higgs doublet models with a softly-broken Z2 symmetry. We discuss the phenomenology of the muon and electron specific Higgs bosons at the Large Hadron Collider; namely we evaluate allowed parameter regions from the current Higgs boson search data and discovery potential of such a Higgs boson at the 14 TeV run.