Tensor force effects and high-momentum components in the nuclear symmetry energy

TL;DR

This paper investigates how tensor forces and high-momentum components influence the nuclear symmetry energy using advanced many-body methods, revealing the dominant role of tensor interactions and the correlation differences between neutron matter and symmetric nuclear matter.

Contribution

It provides a detailed microscopic analysis of the tensor force effects and high-momentum components on the nuclear symmetry energy using Brueckner-Hartree-Fock and Green's function methods.

Findings

Tensor component dominates the symmetry energy.

Neutron matter is less correlated than symmetric nuclear matter.

High-momentum components significantly affect the symmetry energy.

Abstract

We analyze microscopic many-body calculations of the nuclear symmetry energy and its density dependence. The calculations are performed in the framework of the Brueckner-Hartree-Fock and the Self-Consistent Green's Functions methods. Within Brueckner-Hartree-Fock, the Hellmann-Feynman theorem gives access to the kinetic energy contribution as well as the contributions of the different components of the nucleon-nucleon interaction. The tensor component gives the largest contribution to the symmetry energy. The decomposition of the symmetry energy in a kinetic part and a potential energy part provides physical insight on the correlated nature of the system, indicating that neutron matter is less correlated than symmetric nuclear matter. Within the Self-Consistent Green's Function approach, we compute the momentum distributions and we identify the effects of the high momentum components in the symmetry energy. The results are obtained for the realistic interaction Argonne V18 potential, supplemented by the Urbana IX three-body force in the Brueckner-Hartree-Fock calculations.