Natural Suppression of StrongP- andT-Invariance Violations and Calculable Mixing Angles in SU (2) ⊗ U (1)

Permutation symmetry is imposed on an SU(2)LU(1)CP-invariant Lagrangian with six quarks. The mixing angles of the b and t are determined: b decays predominantly to u and a meson containing b should have a lifetime τB≈10^-11 sec or less. A phase in the gauge couplings of b and t causes nonconservation of CP in KL decays that is naturally small. No violations of P and T invariance are induced into the strong interactions by φ=arg(DetM) at the tree level. One-loop corrections yield an upper bound of φ<10^-10(mₛmb)(mₜmb)².