Role of correlations on spin-polarized neutron matter

TL;DR

This paper investigates how nucleon-nucleon interactions and correlations influence the spin symmetry energy in neutron matter using a microscopic Brueckner--Hartree--Fock approach with realistic potentials.

Contribution

It provides a detailed analysis of the contributions of different interaction terms to the spin symmetry energy in neutron matter, emphasizing the role of correlations.

Findings

Main contribution from the S=0 channel, especially $^1S_0$ and $^1D_2$ partial waves.

Correlations significantly affect the kinetic energy in spin-polarized neutron matter.

The analysis highlights the importance of the S=0 channel in spin symmetry energy.

Abstract

Using the Hellmann--Feynman theorem we analyze the contribution of the different terms of the nucleon-nucleon interaction to the spin symmetry energy of neutron matter. The analysis is performed within the microscopic Brueckner--Hartree--Fock approach using the Argonne V18 realistic potential plus the Urbana IX three-body force. The main contribution to the spin-symmetry energy of neutron matter comes from the S=0 channel, acting only in the non-polarized neutron matter, in particular the $^1S_0$ and the $^1D_2$ partial waves. The importance of correlations in spin-polarized neutron matter is estimated by evaluating the kinetic energy difference between the correlated system and the underlying Fermi sea.