Fermion mass hierarchy and g-2 anomalies in an extended 3HDM Model

TL;DR

This paper introduces an extended 3HDM that explains the fermion mass hierarchy through loop suppression, accounts for dark matter and g-2 anomalies, and predicts observable charged lepton flavor violation.

Contribution

It presents a novel 3HDM extension with inert scalars and vector-like fermions that generates fermion masses radiatively and addresses multiple beyond Standard Model phenomena.

Findings

Successfully reproduces SM fermion masses and mixings.

Explains dark matter relic density and g-2 anomalies.

Predicts charged LFV decays within experimental reach.

Abstract

We propose an extension of the three-Higgs-doublet model (3HDM), where the Standard Model (SM) particle content is enlarged by the inclusion of two inert $SU_{2L}$ scalar doublets, three inert and two active electrically neutral gauge singlet scalars, charged vector like fermions and Majorana neutrinos. These additional particles are introduced to generate the SM fermion mass hierarchy from a sequential loop suppression mechanism. In our model the top and exotic fermion masses appear at tree level, whereas the remaining fermions get their masses radiatively. Specifically, bottom, charm, tau and muon masses appear at 1-loop; the masses for the light up, down and strange quarks as well as for the electron at 2-loop and masses for the light active neutrinos at 3-loop. Our model successfully accounts for SM fermion masses and mixings and accommodates the observed Dark Matter relic density, the electron and muon anomalous magnetic moments, as well the constraints arising from charged Lepton Flavor Violating (LFV) processes. The proposed model predicts charged LFV decays within the reach of forthcoming experiments.