Effective Interactions In Neutron-Rich Matter

TL;DR

This paper reviews the role of effective interactions in neutron-rich matter, emphasizing the importance of the nuclear equation of state (EOS) for astrophysical and laboratory phenomena, and explores constraints from nuclear data and implications for neutron stars.

Contribution

It presents recent studies on spin-polarized neutron matter and demonstrates how terrestrial nuclear data can constrain the nuclear EOS relevant for astrophysical applications.

Findings

Constraints on the density dependence of the nuclear symmetry energy.

Implications for the stability of neutron-rich matter.

Potential to constrain the rate of change of gravitational constant G.

Abstract

Properties of effective interactions in neutron-rich matter are reflected in the medium's equation of state (EOS), which is a relationship among several state variables. Spin and isospin asymmetries play an important role in the energy balance and could alter the stability conditions of the nuclear EOS. The EOS has far-reaching consequences for numerous nuclear processes in both the terrestrial laboratories and the cosmos. Presently the EOS, especially for neutron-rich matter, is still very uncertain. Heavy-ion reactions provide a unique means to constrain the EOS, particularly the density dependence of the nuclear symmetry energy. On the other hand, microscopic, self-consistent, and parameter-free approaches are ultimately needed for understanding nuclear properties in terms of the fundamental interactions among the basic constituents of nuclear systems. In this talk, after a brief review of our recent studies on spin-polarized neutron matter, we discuss constraining the changing rate of the gravitational constant $G$ and properties of (rapidly) rotating neutron stars by using a nuclear EOS partially constrained by the latest terrestrial nuclear laboratory data.