Testing Minimal Flavor Violation in Leptoquark Models of the $R_{K^{(*)}}$ Anomaly

TL;DR

This paper investigates whether minimal flavor violation can explain the $R_{K^{(*)}}$ anomaly via leptoquark models and finds that current experimental constraints exclude this possibility.

Contribution

It provides a comprehensive analysis of MFV constraints on leptoquark models addressing the $R_{K^{(*)}}$ anomaly, demonstrating their incompatibility.

Findings

MFV in leptoquark models is excluded by experimental constraints

Multiple processes collectively rule out MFV explanations for the anomaly

Leptoquark models require non-MFV structures to explain $R_{K^{(*)}}$

Abstract

The $R_{K^{(*)}}$ anomaly can be explained by tree level exchange of leptoquarks. We study the consequences of subjecting these models to the principle of minimal flavor violation (MFV). We consider MFV in the linear regime, and take the charged lepton Yukawa matrix to be the only spurion that violates lepton flavor universality. We find that a combination of constraints from a variety of processes -- $b\to s\mu\mu$, $b\to s\tau\tau$, $b\to s\nu\nu$, $b\bar b\to\tau\tau$ and $b\to c\tau\nu$ -- excludes MFV in these models.