Flavon exchange effects in models with abelian flavor symmetry
In models with Abelian flavor symmetry the small mixing angles and mass ratios of quarks and leptons are typically given by powers of small parameters characterizing the spontaneous breaking of flavor symmetry by ``flavon'' fields. If the scale of the breaking of flavor symmetry is near the weak scale, flavon exchange can lead to interesting flavor-violating and $\mathrm{CP}$ violating effects. These are studied. It is found that ${d}_{e},$ $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\mu}}e+\ensuremath{\gamma},$ and $\ensuremath{\mu}\ensuremath{-}e$ conversion on nuclei can be near present limits. For a significant range of parameters $\ensuremath{\mu}\ensuremath{-}e$ conversion can be the most sensitive way to look for such effects.