125 GeV Higgs boson rare decays in a flavor-dependent $U(1)_F$ model

TL;DR

This paper explores how a flavor-dependent $U(1)_F$ model modifies Higgs boson decay channels, flavor-changing processes, and electroweak precision observables, revealing potential deviations from Standard Model predictions due to an extended scalar sector.

Contribution

It introduces a detailed analysis of Higgs decays and flavor-changing processes within a flavor-dependent $U(1)_F$ model, highlighting the impact of an extended scalar sector on observable phenomena.

Findings

Altered Higgs decay signal strengths compared to Standard Model.

Enhanced flavor-changing neutral current processes.

Constraints from electroweak precision measurements.

Abstract

In this work, we analyze the Higgs boson decay channels, specifically, $h{\rightarrow}\gamma\gamma$, $h{\rightarrow} VV^*$ (with $V=Z,W$), and $h{\rightarrow} f\bar{f}$ (for $f=b,c,\tau$) within the flavor-dependent $U(1)_F$ model (FDM). We also investigate processes induced by flavor-changing neutral currents, including the decays $\bar B \to X_s\gamma$ and $B_s^0 \to \mu^+\mu^-$, the top quark decays $t\to c h$ and $t\to u h$, and the lepton flavor-violating decays $\tau \to 3e$, $\tau \to 3\mu$, and $\mu \to 3e$. Furthermore, we incorporate the electroweak precision observables constraints via the S, T, and U parameters. Compared to the Standard Model, the scalar sector of the FDM is extended by two Higgs doublets and one Higgs singlet, which affects the 125 GeV Higgs properties significantly. Meanwhile, the decays $h{\rightarrow} Z\gamma$, $h\rightarrow MZ$, and $h{\rightarrow} M\gamma$ (where $M$ is a vector meson $(\rho,\omega,\phi,J/\Psi,\Upsilon)$ of the Standard-Model-like Higgs are studied, and we illustrate how changes in the scalar sector and the Yukawa coupling influence the signal strengths for the 125 GeV Higgs decay channels and the Higgs mass in the FDM.