Models for SU(N) ×SU(N) symmetry breaking with extremum constraints

Abstract

The extremum properties of some functions defined on the compact groups or their representations are investigated. The extremum constraints for the vacuum expectation value of U(N) ×U(N) and SU(N) ×SU(N) ⧠ [Z2(P) ×Z2(C)] symmetry breaking perturbation Hamiltonian are used to determine the models compatible with nonnegative particle mass spectrum in the first perturbation order. Some model-independent properties inferred by extremum constraints of chiral and CP-symmetry breaking are also examined.