# $R_2$ as a single leptoquark solution to $R_{D^{(*)}}$ and $R_{K^{(*)}}$

## TL;DR

This paper demonstrates that the $R_2$ leptoquark can simultaneously explain anomalies in $R_{K^{(*)}}$ and $R_{D^{(*)}}$ with minimal couplings, and proposes a neutrino mass model involving $S_3$ to address related constraints.

## Contribution

It shows that a single $R_2$ leptoquark can account for multiple B-meson decay anomalies without large couplings, and introduces a neutrino mass model with $S_3$ leptoquark.

## Key findings

- $R_2$ leptoquark explains $R_{K^{(*)}}$ and $R_{D^{(*)}}$ anomalies.
- Small couplings suffice to fit the data.
- Neutrino mass model with $S_3$ alleviates tension with $B_c o au
u$ limits.

## Abstract

We show that, up to plausible uncertainties in BR$(B_c\to \tau \nu)$, the $R_2$ leptoquark can simultaneously explain the observation of anomalies in $R_{K^{(*)}}$ and $R_{D^{(*)}}$ without requiring large couplings. The former is achieved via a small coupling to first generation leptons which boosts the decay rate $\Gamma(\bar B\to \bar K^{(*)}e^+e^-)$. Finally we motivate a neutrino mass model that includes the $S_3$ leptoquark which can alleviate a mild tension with the most conservative limits on BR$(B_c\to \tau \nu)$.