Three-body force effect on nucleon momentum distributions in asymmetric nuclear matter within the framework of the extended BHF approach

TL;DR

This study examines how three-body forces influence neutron and proton momentum distributions in asymmetric nuclear matter using an extended Brueckner-Hartree-Fock approach, revealing density-dependent effects on depletion.

Contribution

It introduces a microscopic TBF into the extended BHF framework to analyze its impact on nucleon momentum distributions in asymmetric nuclear matter.

Findings

TBF effects are negligible at low densities.

At high densities, TBF significantly enhances nucleon Fermi sea depletion.

Asymmetry increases differences in neutron and proton distributions.

Abstract

We have investigated the three-body force (TBF) effect on the neutron and proton momentum distributions in asymmetric nuclear matter within the framework of the extended Brueckner-Hartree-Fock approach by adopting the $AV18$ two-body interaction plus a microscopic TBF. In asymmetric nuclear matter, it is shown that the neutron and proton momentum distributions become different from their common distribution in symmetric nuclear matter. The predicted depletion of the proton hole states increases while the neutron one decreases as a function of isospin-asymmetry. The TBF effect on the neutron and proton momentum distributions turns out to be negligibly weak at low densities around and below the normal nuclear density. The TBF effect is found to become sizable only at high densities well above the saturation density, and inclusion of the TBF leads to an overall enhancement of the depletion of the neutron and proton Fermi seas.