Properties of nuclear matter in relativistic Brueckner-Hartree-Fock model with high-precision charge-dependent potentials

TL;DR

This paper investigates nuclear matter properties using a relativistic Brueckner-Hartree-Fock model with high-precision charge-dependent potentials, revealing how pion-nucleon coupling and tensor components influence saturation and symmetry breaking effects.

Contribution

It introduces the use of high-precision charge-dependent Bonn potentials in a relativistic Brueckner-Hartree-Fock framework to analyze nuclear matter properties, including saturation, CSB, and CIB effects.

Findings

Reasonable saturation properties are achieved with pseudovector pion-nucleon coupling.

Saturation properties strongly correlate with tensor components of NN potentials.

Charge symmetry and independence breaking effects are quantified in nuclear matter.

Abstract

Properties of nuclear matter are investigated in the framework of relativistic Brueckner-Hartree-Fock model with the latest high-precision charge-dependent Bonn (pvCD-Bonn) potentials, where the coupling between pion and nucleon is adopted as pseudovector form. These realistic pvCD-Bonn potentials are renormalized to effective nucleon-nucleon ($NN$) interactions, $G$ matrices. They are obtained by solving the Blankenbecler-Sugar (BbS) equation in nuclear medium. Then, the saturation properties of symmetric nuclear matter are calculated with pvCD-Bonn A, B, C potentials. The energies per nucleon are around $-10.72$ MeV to $-16.83$ MeV at saturation densities, $0.139$ fm$^{-3}$ to $0.192$ fm$^{-3}$ with these three potentials, respectively. It clearly demonstrates that the pseudovector coupling between pion and nucleon can generate reasonable saturation properties comparing with pseudoscalar coupling. Furthermore, these saturation properties have strong correlations with the tensor components of $NN$ potentials, i.e., the $D$-state probabilities of deuteron, $P_D$ to form a relativistic Coester band. In addition, the charge symmetry breaking (CSB) and charge independence breaking (CIB) effects are also discussed in nuclear matter from the partial wave contributions with these high-precision charge-dependent potentials. In general, the magnitudes of CSB from the differences between $nn$ and $pp$ potentials are about $0.05$ MeV, while those of CIB are around $0.35$ MeV from the differences between $np$ and $pp$ potentials. Finally, the equations of state of asymmetric nuclear matter are also calculated with different asymmetry parameters. It is found that the effective neutron mass is larger than the proton one in neutron-rich matter.