Di-nucleon structures in homogeneous nuclear matter based on two- and three-nucleon interactions

TL;DR

This paper explores di-nucleon structures in homogeneous nuclear matter using the Brueckner-Hartree-Fock approach with various realistic nucleon interactions, highlighting the importance of di-nucleon bound states for solution stability at low densities.

Contribution

It provides a detailed analysis of di-nucleon bound states in nuclear matter using multiple realistic potentials, emphasizing their role in the stability of self-consistent solutions.

Findings

Di-nucleon bound states are crucial for solution stability at low densities.

Coexisting BHF solutions are robust across different realistic potentials.

Di-nucleon structures are characterized in specific spin-isospin channels.

Abstract

We investigate homogeneous nuclear matter within the Brueckner-Hartree-Fock (BHF) approach in the limits of isospin-symmetric nuclear matter (SNM) as well as pure neutron matter at zero temperature. The study is based on realistic representations of the internucleon interaction as given by Argonne v18, Paris, Nijmegen I and II potentials, in addition to chiral N$^{3}$LO interactions, including three-nucleon forces up to N$^{2}$LO. Particular attention is paid to the presence of di-nucleon bound states structures in $^1\textrm{S}_0$ and $^3\textrm{SD}_1$ channels, whose explicit account becomes crucial for the stability of self-consistent solutions at low densities. A characterization of these solutions and associated bound states is discussed. We confirm that coexisting BHF single-particle solutions in SNM, at Fermi momenta in the range $0.13-0.3$~fm$^{-1}$, is a robust feature under the choice of realistic internucleon potentials.