# Excesses of muon $g-2$, $R_{D^{(\ast)}}$, and $R_K$ in a leptoquark model

## TL;DR

This paper explores how a model with multiple scalar leptoquarks can simultaneously explain anomalies in muon g-2, B-meson decay ratios R_D, R_D*, R_K, and R_K*, highlighting the roles of different leptoquark types.

## Contribution

It introduces a specific leptoquark model with doublet, triplet, and singlet scalars to address multiple flavor anomalies simultaneously.

## Key findings

- Muon g-2 explained by doublet LQ due to m_t enhancement.
- R_K(*) anomalies require combined effects of doublet and triplet LQs.
- R_D and R_D* excesses depend on singlet LQ interactions.

## Abstract

In this study, we investigate muon $g-2$, $R_{K^{(*)}}$, and $R_{D^{(*)}}$ anomalies in a specific model with one doublet, one triplet, and one singlet scalar leptoquark (LQ). When the strict limits from the $\ell' \to \ell \gamma$, $\Delta B=2$, $B_{s}\to \mu^+ \mu^-$, and $B^+ \to K^+ \nu \bar\nu$ processes are considered, it is difficult to use one scalar LQ to explain all of the anomalies due to the strong correlations among the constraints and observables. After ignoring the constraints and small couplings, the muon $g-2$ can be explained by the doublet LQ alone due to the $m_t$ enhancement, whereas the measured and unexpected smaller $R_{K^{(*)}}$ requires the combined effects of the doublet and triplet LQs, and the $R_D$ and $R_{D^*}$ excesses depend on the singlet LQ through scalar- and tensor-type interactions.