# LHCb anomaly and $B$ physics in flavored Z$^{\prime}$ models with flavored Higgs doublets

## TL;DR

This paper proposes a flavored Z' model with flavored Higgs doublets to explain LHCb's B decay anomalies, predicting flavor-changing currents that could account for observed deviations in B physics processes.

## Contribution

It introduces a novel U(1)' flavor symmetry with flavored Higgs doublets, providing a detailed mechanism for fermion mass hierarchy and flavor-changing interactions relevant to B decay anomalies.

## Key findings

- The model can potentially explain the LHCb B decay anomalies.
- Predictions for other flavor-violating processes are derived.
- Constraints from existing B physics measurements are analyzed.

## Abstract

We study an extended Standard Model with a gauged U(1)$^{\prime}$ flavor symmetry, motivated not only by the fermion mass hierarchy but also by the excesses in $B \to K^{(*)} l l$ reported by the LHCb collaborations. The U(1)$^{\prime}$ charges are assigned to quarks and leptons in a flavor-dependent manner, and flavored Higgs doublets are also introduced in order to detail the Yukawa couplings at the renormalizable level. Then, the fermion mass hierarchy is realized by the vacuum alignment of the Higgs doublets. In this model, flavor-changing currents involving the gauge boson of U(1)$^{\prime}$ and the scalars generated by the Higgs doublets are predicted and the observables in the $B \to K^{(*)} l l$ process possibly deviate from the Standard Model predictions. We study the possibility that these new flavor-changing interactions can explain the excesses in the $B \to K^{(*)} l l$ process, and we derive some predictions for the other flavor-violating processes based on the analysis. We specifically investigate the $\Delta F=2$ processes and the other $B$ decays: e.g., $B \to X_s \gamma$ and $B \to D^{(*)} \tau \nu$, where the deviations are reported by the Belle and $BABAR$ collaborations.