$R_{K^{(*)}}$ with leptoquarks and the origin of Yukawa couplings

TL;DR

This paper presents a model where Yukawa couplings originate from symmetry breaking and mixing with a fourth fermion family, using a scalar leptoquark to explain anomalies in $R_{K^{(*)}}$ linked to fermion mass and mixing structures.

Contribution

It introduces a novel framework connecting Yukawa couplings, $R_{K^{(*)}}$ anomalies, and leptoquark interactions through a $Z_2$ symmetry and vector-like fermions.

Findings

Explains $R_{K^{(*)}}$ anomalies via leptoquark interactions.

Predicts relations between fermion couplings, CKM entries, and mass ratios.

Links Yukawa origin to flavor anomalies.

Abstract

We construct a model where the Yukawa couplings of the Standard Model (SM) fermions arise from the breaking of a $Z_2$ symmetry and through mixing with a fourth family of vector-like fermions. By adding a scalar leptoquark, which is an electroweak triplet and odd under the $Z_2$ symmetry, we obtain an explanation for $R_{K^{(*)}}$ that is linked to the origin of the Yukawa couplings. The coupling of SM fermions to the leptoquark is mediated by the fourth family fermions, and is predicted to be related to CKM entries and mass ratios of SM fermions.