Quark-Lepton Unification and Rare Meson Decays
  We study meson decays mediated by the heavy gauge bosons of the Pati-Salam model of quark-lepton unification. We consider the scenarios in which the tau lepton is associated with the third, second, and first generation of quarks. The most sensitive probes, depending on the scenario, are rare K, pi, and B decays. 
G. Valencia and S. Willenbrock