# Flavored Axions

## TL;DR

Precision flavor experiments can detect flavored QCD axions, providing a complementary approach to traditional searches and probing high PQ breaking scales through flavor-violating couplings linked to Yukawa hierarchies.

## Contribution

The paper introduces a predictive scenario where PQ symmetry is identified with the FN flavor symmetry, relating flavor-violating axion couplings to Yukawa hierarchies.

## Key findings

- Flavor experiments can test PQ scales up to 10^{12} GeV.
- Flavor-violating axion couplings are related to Yukawa hierarchies.
- The scenario is highly predictive with minimal free parameters.

## Abstract

Precision flavor experiments can look for the QCD axion complementarily to usual searches with axion helio- and haloscopes, allowing to test PQ breaking scales as high as $10^{12} \, {\rm GeV}$. Such searches are sensitive to flavor-violating axion couplings, which are generic and potentially sizable whenever SM fermions carry flavor non-universal PQ charges. A particularly predictive scenario is obtained when PQ is identified with the simplest FN flavor symmetry, so that all flavor-violating axion couplings are related to Yukawa hierarchies, up to ${\cal O}(1)$ coefficients.