Flavoured axion-like particles

A consequence is the possible occurrence of flavour-violating decays of hadrons and leptons into light axion-like particles. These exotic signatures are a powerful probe of such kind of scenarios. A well-motivated example is the flavour-violating QCD axion arising in the context of a Froggatt-Nielsen model of fermion masses and mixing. I will discuss both the latter specific case and the more generic setup with a focus on the phenomenological consequences at future experiments, especially searches for lepton flavour violation.