  Many popular attempts to explain the observed patterns of fermion masses
involve a flavon field. Such weakly coupled scalar fields tend to dominate the
energy density of the universe before they decay. If the flavon decay happens
close to the electroweak transition, the right-handed electrons stay out of
equilibrium until the sphalerons shut off. We show that an asymmetry in the
right-handed charged leptons produced in the decay of a flavon can explain the
baryon asymmetry of the universe.
