Properties of neutron star crust with improved nuclear physics: Impact of chiral EFT interactions and experimental nuclear masses

TL;DR

This study investigates neutron star crust properties using a liquid-drop model informed by chiral EFT interactions and experimental nuclear masses, revealing how different properties are constrained by nuclear physics at various densities.

Contribution

It introduces an improved model combining chiral EFT and experimental data to analyze neutron star crusts, highlighting the influence of different nuclear matter properties.

Findings

Crust cluster properties are mainly constrained by experimental nuclear masses.

Energy per particle, pressure, and sound speed are influenced by low-density neutron matter predictions.

Different nuclear physics models significantly affect certain neutron star crust properties.

Abstract

A compressible liquid-drop approach adjusted to uniform matter many-body calculations based on chiral EFT interactions and to the experimental nuclear masses is used to investigate the neutron star crust properties. Eight chiral EFT hamiltonians and a representative phenomenological force (SLy4) are confronted. We show that some properties of the crust, e.g. clusters mass, charge, and asymmetry, are mostly determined by symmetric matter properties close to saturation density and are therefore mainly constrained by experimental nuclear masses, while other properties, e.g., energy per particle, pressure, sound speed, are mostly influenced by low-density predictions in neutron matter, where chiral EFT and phenomenological forces substantially differ.