Binding energy of nuclear matter from a physical particle spectrum

Abstract

We use a non-vanishing potential energy for the intermediate particle states in the Bethe-Brueckner expansion for the binding energy of nuclear matter. We identify this potential energy with the depth of the optical-model potential. It turns out that, in addition to this physical meaning, the potential spectrum shares the properties previously required by several authors : it presents no gap at the Fermi momentum k F; it is small and possesses the proper energy and density dependence at high momenta. Detailed calculations are performed with Reid's hard core interaction. The two-hole contribution B 2 is found to be −12.2 MeV at the saturation momentum k F = 1.30 fm −1. A crude estimate of the three- and four-hole line contributions gives B = −15.60 MeV, k F = 1.34fm −1. These results lie closer to the empirical values than those obtained in the conventional calculations where the potential energy in particle states is set to zero : In the latter case one finds, in the two-hole line approximation, B 2, = − 9.05 MeV, k F = 1.30 fm −1 ; by estimating the three- and four-hole line contribution, one obtains B = −9.70 MeV, k F = 1.36 fm −1.