The Microscopic Approach to Nuclear Matter and Neutron Star Matter

TL;DR

This paper reviews microscopic approaches to understanding the nuclear matter equation of state, emphasizing their importance for modeling neutron star matter and related phenomena, with a focus on symmetry energy and its density dependence.

Contribution

It highlights the significance of microscopic methods in accurately predicting the properties of nuclear and neutron star matter, especially concerning symmetry energy.

Findings

Microscopic approaches provide predictive power for nuclear matter.

Symmetry energy's density dependence is crucial yet poorly constrained.

Understanding neutron star properties depends on accurate nuclear matter models.

Abstract

We review a variety of theoretical and experimental investigations aimed at improving our knowledge of the nuclear matter equation of state. Of particular interest are nuclear matter extreme states in terms of density and/or isospin asymmetry. The equation of state of matter with unequal concentrations of protons and neutrons has numerous applications. These include heavy-ion collisions, the physics of rare, short-lived nuclei and, on a dramatically different scale, the physics of neutron stars. The "common denominator" among these (seemingly) very different systems is the symmetry energy, which plays a crucial role in both the formation of the neutron skin in neutron-rich nuclei and the radius of a neutron star (a system 18 orders of magnitude larger and 55 orders of magnitude heavier). The details of the density dependence of the symmetry energy are not yet sufficiently constrained. Throughout this article, our emphasis will be on the importance of adopting a microscopic approach to the many-body problem, which we believe to be the one with true predictive power.