Horizontal flavor chirality and a minimal Higgs system are combined for uniquely establishing a "canonical" fermion mass matrix, reflecting pure nearest-neighbor Yukawa interactions, for any arbitrary number of generations. The quark-mass matrices then become tightly correlated by the anomaly-free equations, admitting neither strong nor weak $\mathrm{CP}$ nonconservation. The resulting horizontal $\mathrm{CP}$ nonconservation is then truly superweak, signifying the existence of an energy oasis around a few hundred teraelectronvolts.

• Received 18 December 1980

DOI:https://doi.org/10.1103/PhysRevLett.46.691