Origin of Yukawa couplings for Higgs and leptoquarks

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 $R_{K^{(\ast )}}$ 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.

20 pages, 7 figures. v2: references added

References in corpus (11)

• Test of lepton universality using $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ decays
• $R_K$ and future $b\to s\ell \ell$ BSM opportunities
• Lepton Flavor Violation in B Decays?
• Baryon Number and Lepton Universality Violation in Leptoquark and Diquark Models
• Hint of Lepton Flavour Non-Universality in $B$ Meson Decays
• The Leptoquark Hunter's Guide: Pair Production
• Leptoquark Flavor Patterns & B Decay Anomalies
• The role of the $S_3$ GUT leptoquark in flavor universality and collider searches
• Flavourful $Z^{\prime }$ models for $R_{K^{(\ast )}}$
• Flavour from accidental symmetries
• Testing Minimal Flavor Violation in Leptoquark Models of the $R_{K^{(\ast )}}$ Anomaly

Cited by in corpus (5)

• Combined explanations of $(g-2{)}_{\mu }$, $R_{D^{(\ast )}}$, $R_{K^{(\ast )}}$ anomalies in a two-loop radiative neutrino mass model
• Twin Pati-Salam theory of flavour with a TeV scale vector leptoquark
• Marriage between neutrino mass and flavor anomalies
• The fate of $V_1$ vector leptoquarks: the impact of future flavour data
• Fermiophobic $Z^{\prime }$ model for simultaneously explaining the muon anomalies $R_{K^{(\ast )}}$ and $(g-2{)}_{\mu }$