Radiative seesaw-type mechanism of fermion masses and non-trivial quark mixing

Carolina Arbeláez,Ivan Schmidt,Sergey Kovalenko,A E Cárcamo Hernández

doi:10.1140/epjc/s10052-017-4948-9

Abstract

We propose a predictive inert two-Higgs doublet model, where the standard model (SM) symmetry is extended by S_{3}otimes Z_{2}otimes Z_{12} and the field content is enlarged by extra scalar fields, charged exotic fermions and two heavy right-handed Majorana neutrinos. The charged exotic fermions generate a non-trivial quark mixing and provide one-loop-level masses for the first- and second-generation charged fermions. The masses of the light active neutrinos are generated from a one-loop-level radiative seesaw mechanism. Our model successfully explains the observed SM fermion mass and mixing pattern.

Highlights

Md ms [100–102], which seems to imply a radiative seesaw mechanism of fermion mass generation, where the Cabbibo mixing arises from the downtype quark sector, whereas the up quark sector contributes to the remaining mixing angles
At tree level only the third-generation charged fermions acquire masses and there is no quark mixing, while the first- and second-generation charged fermion masses and the quark mixing arise from one-loop-level radiative seesaw-type mechanism, triggered by virtual Z2-charged scalar fields and electrically charged exotic fermions running inside the loops
Light active neutrino masses are generated from a one-loop-level radiative seesaw mechanism

Summary

Introduction

Md ms [100–102], which seems to imply a radiative seesaw mechanism of fermion mass generation, where the Cabbibo mixing arises from the downtype quark sector, whereas the up quark sector contributes to the remaining mixing angles Inspired with this observation we propose an extension of the inert two Higgs doublet model (2HDM) realizing this idea. In our model a mismatch between the down- and up-type quark mass matrix textures is introduced, by distinguishing the two Higgs doublets with respect to the Z2 flavor symmetry, preserved at all scales. One Z2 odd SM singlet scalar η (apart from the Z2 odd scalar doublet φ2) is needed to implement the radiative seesaw mechanism of fermion mass generation It yields a non-trivial quark mixing, provides masses for the first- and second-generation charged fermions and contributes to the light active neutrino masses.

The model

R m B2

Quark masses and mixings

Lepton masses and mixings

Dark matter candidate

Conclusions