Cosmological Baryon Asymmetry and Kaon CP Violation from a Common Source

We extend an earlier model for radiatively generated fermion masses based on the Pati-Salam group to include CP violation. Spontaneous CP violation in the early universe gives rise to a complex mass matrix for heavy sterile neutrinos. The out-of-equilibrium decay of these neutrinos generates a $B-L$ asymmetry. The sterile neutrinos also act as a mass seed in generating one-loop (complex) mass matrices for the quarks. Thus, the two low energy manifestations of CP violation -- the CKM phase and the baryon number asymmetry -- can both be traced in a calculable way to a common source.