A comparison between Brueckner's approach and the ?00-approximation in the many-body theory of nuclear matter

Abstract

We compare the Brueckner-Hartree-Fock and theλ00-approximations in nuclear matter theory. We use a back-to-back Yamaguchi potential with no tensor part, and which acts only in relative s states. We calculate and discuss the following quantities: saturation density, average binding energy per nucleon, strength and energy dependence of the real and of the imaginary parts of the optical model potential for the Fermi momentum equal to 1.9 fm−1. In both approximations, we investigate the low-energy asymptotic behaviour of the imaginary part of the mass operator. We discuss the existence of a narrow enhancement of the effective mass, it lies in the vicinity of the Fermi surface in Brueckner's approach, but significantly somewhat above the Fermi surface in theλ00-approximation. In the case of the binding energy, both approximations are nearly equivalent.