Constraints on the isospin summetry in the nuclear mean field

The conventional Slater Determinant (S.D.) of the Hartree-Fock (H.F.) method cannot be considered, in general, as an isospin eigenfunction. The isospin eigenfunction turns out to be the linear combination of S.D. of nuclear analogue states. It is, therfore, quite cumbersome, though not impossible, to solve H.F. equation with the combined S.D. It seems to be simpler to use the ''configuration mixing'' picture by means of the isospin qusi-particle formalism. Some advantages of this formalism in the treatment of the two-body constraint are also apparently shown. (Author)