# Origin of Yukawa couplings for Higgs and leptoquarks

## TL;DR

This paper introduces a model linking Higgs Yukawa couplings to leptoquark interactions via a shared origin from mixing with a vector-like family, predicting lepton non-universality in B decays and explaining certain anomalies.

## Contribution

The model uniquely connects Higgs and leptoquark couplings through a discrete symmetry and mixing, providing a novel explanation for B decay anomalies and lepton non-universality.

## Key findings

- Predicts lepton non-universality in B to K decays
- Explains R_{K^{(*)}} anomalies with a ~1 TeV leptoquark
- Constraints from B_s mixing and tau to mu gamma considered

## Abstract

We propose a model in which the Yukawa couplings of Higgs doublets are related to the couplings of the chiral fermions to a scalar leptoquark triplet. This is due to their common origin via mixing with a vector-like family distinguished by a discrete $Z_5$ symmetry, under which only the three chiral families are neutral. The model predicts lepton non-universality in $B$ to $K$ decays, depending on the leptoquark mass, $V_{ts}$ and $m_\mu/m_\tau$. The model can only consistently explain the anomalies in $R_{K^{(*)}}$ for a leptoquark mass close to the collider lower bound of about $1~\text{TeV}$. Constraints from $B_s - \bar{B}_s$ mixing and eventually $\tau \to \mu \gamma$ become relevant for low leptoquark masses and large couplings, while $\mu \to e \gamma$ remains automatically under control due to the absence of leptoquark couplings to the electron in this model.