Contribution of high order partial waves to the binding energy of nuclear matter for model interactions

Abstract

In the framework of the version of the Brueckner-Hartree-Fock approximation which uses a self-consistent single-particle potential above the Fermi surface, we evaluate the contribution of high order partial waves to the binding energy of nuclear matter. In the case of the nucleon-nucleon interactions of Gammel and Thaler (5200), of Baker, Hind and Kahane, and of Ohmura, Morita and Yamada, we show that at high density these contributions are attractive and sizeable. This helps to remove the apparent discrepancy between the results of the Bethe-Brueckner expansion on the one hand, and the upper bound evaluated from variational approaches on the other hand. We describe why this finding is compatible with the results obtained from the standard version of the Bethe-Brueckner expansion, in which the single-particle potential is set to zero above the Fermi surface. We argue that high order partial waves play a less important role in the case of realistic nucleon-nucleon interactions.