Properties of asymmetric nuclear matter in different approaches

TL;DR

This paper compares various phenomenological and microscopic approaches to understanding the properties of asymmetric nuclear matter, focusing on high-density behavior and the isovector effective mass in neutron-rich environments.

Contribution

It provides a comprehensive comparison of different many-body approaches, highlighting their predictions for asymmetric nuclear matter and the behavior of the isovector effective mass.

Findings

Microscopic approaches align with phenomenological models at high densities.

The isovector effective mass varies significantly in neutron-rich matter.

All models aim to reproduce empirical saturation properties.

Abstract

Properties of asymmetric nuclear matter are derived from various many-body approaches. This includes phenomenological ones like the Skyrme Hartree-Fock and relativistic mean field approaches, which are adjusted to fit properties of nuclei, as well as more microscopic attempts like the Brueckner-Hartree-Fock approximation, a self-consistent Greens function method and the so-called $V_{lowk}$ approach, which are based on realistic nucleon-nucleon interactions which reproduce the nucleon-nucleon phase shifts. These microscopic approaches are supplemented by a density-dependent contact interaction to achieve the empirical saturation property of symmetric nuclear matter. The predictions of all these approaches are discussed for nuclear matter at high densities in $\beta$-equilibrium. Special attention is paid to behavior of the isovector component of the effective mass in neutron-rich matter.