The flavor-dependent $U(1)_F$ model

TL;DR

This paper introduces a flavor-dependent $U(1)_F$ extension of the Standard Model that addresses flavor hierarchies, neutrino masses, and predicts rare decay processes, providing a comprehensive new framework.

Contribution

It proposes a novel flavor-dependent $U(1)_F$ gauge extension with specific particle content that explains flavor puzzles and neutrino masses naturally.

Findings

Explains flavor hierarchies and mixings.

Predicts rare decay processes consistent with current bounds.

Provides a natural mechanism for Majorana neutrino masses.

Abstract

A flavor-dependent model (FDM) is proposed in this work. The model extends the Standard Model by an extra $U(1)_F$ local gauge group, two scalar doublets, one scalar singlet and two right-handed neutrinos, where the additional $U(1)_F$ charges are related to the particles' flavor. The new fermion sector in the FDM can explain the flavor mixings puzzle and the mass hierarchy puzzle simultaneously, and the nonzero Majorana neutrino masses can be obtained naturally by the Type I see-saw mechanism. In addition, the $B$ meson rare decay processes $\bar B \to X_s\gamma$, $B_s^0 \to \mu^+\mu^-$, the top quark rare decay processes $t\to ch$, $t\to uh$ and the $\tau$ lepton flavor violation processes $\tau\to 3e$, $\tau\to 3\mu$, $\mu\to 3e$ predicted in the FDM are analyzed.