Maximal Flavour Violation: a Cabibbo mechanism for leptoquarks

TL;DR

This paper introduces a mechanism enabling significant flavour violation in quark-lepton interactions within a specific model, explaining B-meson decay anomalies while maintaining consistency with other experimental constraints.

Contribution

It proposes a novel flavour violation mechanism integrated into a renormalizable 4321 model, addressing B-meson anomalies and aligning with existing experimental bounds.

Findings

Successfully explains B-meson decay anomalies

Maintains consistency with flavour and electroweak constraints

Highlights complementarity of indirect and direct searches

Abstract

We propose a mechanism that allows for sizeable flavour violation in quark-lepton currents, while suppressing flavour changing neutral currents in quark-quark and lepton-lepton sectors. The mechanism is applied to the recently proposed 4321 renormalizable model, which can accommodate the current experimental anomalies in $B$-meson decays, both in charged and neutral currents, while remaining consistent with all other indirect flavour and electroweak precision measurements and direct searches at high-$p_T$. To support this claim, we present an exhaustive phenomenological survey of this fully calculable UV complete model and highlight the rich complementarity between indirect and direct searches.