Effective interactions for the SM fermion mass hierarchy and their possible UV realization

TL;DR

This paper proposes an extended two-Higgs-doublet model with a global U(1) symmetry that explains the fermion mass hierarchy, neutrino masses, and addresses anomalies in muon and electron g-2, consistent with experimental constraints.

Contribution

It introduces a novel 2HDM framework combining the Universal Seesaw and Zee-Babu mechanisms, providing a unified explanation for fermion masses, neutrino masses, and flavor anomalies.

Findings

Model explains SM fermion mass hierarchy and mixings.

Predicts charged lepton flavor violation rates within experimental reach.

Accommodates muon and electron g-2 anomalies successfully.

Abstract

We built an extended 2HDM theory with a spontaneously broken $U(1) _{X}$ global symmetry, where the tree level Universal Seesaw Mechanism generates the mass hierarchy of the Standard Model charged fermions and the Zee-Babu mechanism produces tiny active neutrino masses. The third family of SM charged fermions gets tree level masses from Yukawa interactions involving the Higgs doublets $H_1$ (for the top quark) and $H_2$ (for the bottom quark and tau lepton). The model under consideration is consistent with SM fermion masses and mixings, with the muon and electron $g-2$ anomalies and successfully accommodates the constraints arising from charged lepton flavor violation and meson oscillations. The proposed model predicts rates for charged lepton flavor violating decays within the reach of forthcoming experiments.