The properties of nuclear matter with lattice $NN$ potential in relativistic Brueckner-Hartree-Fock theory

TL;DR

This paper constructs a relativistic microscopic model of nuclear matter using lattice-derived nucleon-nucleon potentials, fitting meson exchange parameters, and analyzing properties of symmetric and neutron matter.

Contribution

It introduces a new method to incorporate lattice $NN$ potentials into RBHF theory via fitted one-boson-exchange potentials, providing insights into nuclear matter properties.

Findings

Relativistic binding energies are more negative than non-relativistic ones.

The equations of state for neutron matter are similar in both frameworks.

Two parameter sets (LOBEP1 and LOBEP2) effectively reproduce lattice $NN$ force behaviors.

Abstract

We study the properties of nuclear matter with lattice nucleon-nucleon ($NN$) potential in the relativistic Brueckner-Hartree-Fock (RBHF) theory. To use this potential in such a microscopic many-body theory, we firstly have to construct a one-boson-exchange potential (OBEP) based on the latest lattice $NN$ potential. Three mesons, pion, $\sigma$ meson, and $\omega$ meson, are considered. Their coupling constants and cut-off momenta are determined by fitting the on-shell behaviors and phase shifts of the lattice force, respectively. Therefore, we obtain two parameter sets of the OBEP potential (named as LOBEP1 and LOBEP2) with these two fitting ways. We calculate the properties of symmetric and pure neutron matter with LOBEP1 and LOBEP2. In non-relativistic Brueckner-Hartree-Fock case, the binding energies of symmetric nuclear matter are around $-3$ and $-5$ MeV at saturation densities, while it becomes $-8$ and $-12$ MeV in relativistic framework with $^1S_0,~^3S_1,$ and $^3D_1$ channels using our two parameter sets. For the pure neutron matter, the equations of state in non-relativistic and relativistic cases are very similar due to only consideration $^1S_0$ channel with isospin $T=1$ case.