AN EQUIVALENT REDUCTION OF THE BETHE-SALPETER-EQUATION FOR MULTI-FERMION BOUND-STATES

By means of the renormalized Dirac spinor wave function and through the introduction of an effective interaction operator, the exact Bethe-Salpeter equation for multi-fermion bound states has been reduced to an equivalent Pauli-Schrodinger equation. As a result, the specific form of the latter equation in the static approximation has directly been given as well. In comparison of the effective interaction operator appearing in the Pauli-Schrodinger equation with the corresponding S-matrix, a substantial difference between both interactions acting in the bound state and the scattering state emerges which is important to determine an interaction potential in the bound state.