Chiral three-nucleon forces and neutron matter

TL;DR

This paper investigates neutron matter using chiral three-nucleon forces, deriving density-dependent interactions, and analyzing their effects on energy, symmetry energy, and superfluid pairing, with emphasis on theoretical uncertainties.

Contribution

It introduces a detailed calculation of neutron matter properties incorporating chiral three-nucleon forces and assesses their impact on various physical quantities.

Findings

Neutron matter is perturbative at nuclear densities.

Chiral three-nucleon forces influence the symmetry energy and its density dependence.

Theoretical uncertainties in neutron matter energy are quantified.

Abstract

We calculate the properties of neutron matter and highlight the physics of chiral three-nucleon forces. For neutrons, only the long-range 2 pi-exchange interactions of the leading chiral three-nucleon forces contribute, and we derive density-dependent two-body interactions by summing the third particle over occupied states in the Fermi sea. Our results for the energy suggest that neutron matter is perturbative at nuclear densities. We study in detail the theoretical uncertainties of the neutron matter energy, provide constraints for the symmetry energy and its density dependence, and explore the impact of chiral three-nucleon forces on the S-wave superfluid pairing gap.