Shell States of Neutron Rich Matter

TL;DR

This paper explores the equation of state for neutron-rich matter using a Relativistic Mean Field model, discovering new shell states that minimize free energy and could influence super heavy nuclei properties.

Contribution

It introduces the concept of shell states in neutron-rich matter within a RMF framework, highlighting their energy minimization and structural characteristics.

Findings

Shell states minimize free energy over a range of densities.

Shell states involve both inside and outside surfaces, reducing Coulomb energy.

Transition from nuclei to shell states to uniform matter with increasing density.

Abstract

The equation of state (EOS) for nuclear and neutron rich matter is investigated in a Relativistic Mean Field (RMF) model. New shell states are found that minimize the free energy per baryon, calculated in a spherical Wigner-Seitz (WS) approximation, over a significant range of baryon densities. These shell states, that have both inside and outside surfaces, minimize the Coulomb energy of large proton number configurations at the expense of a larger surface energy. This is related to a possible depression in the central density of super heavy nuclei. As the baryon density increases, we find the system changes from normal nuclei, to shell states, and then to uniform matter.