Inferring three-nucleon couplings from multi-messenger neutron-star observations

TL;DR

This paper introduces a novel framework to infer three-nucleon couplings in dense matter directly from neutron star observations, bridging microscopic nuclear physics and astrophysical data to test theoretical models.

Contribution

The authors develop a new method to extract three-nucleon interaction parameters from astrophysical neutron star measurements, linking quantum field theory couplings with observational data.

Findings

Constraints on three-nucleon couplings from GW170817 and X-ray data.

Next-generation neutron star observations can tightly constrain nuclear interaction parameters.

Method establishes a direct connection between microscopic nuclear physics and astrophysical observations.

Abstract

Understanding the interactions between nucleons in dense matter is an important challenge in theoretical physics. Effective field theories have emerged as the dominant approach to address this problem at low energies, with many successful applications to the structure of nuclei and the properties of dense nucleonic matter. However, how far into the interior of neutron stars these interactions can describe dense matter is an open question. Here, we develop a framework that enables the inference of three-nucleon couplings in dense matter directly from astrophysical neutron star observations. We apply this formalism to the LIGO/Virgo gravitational-wave event GW170817 and the X-ray measurements from NASA's Neutron Star Interior Composition Explorer and establish direct constraints for the couplings that govern three-nucleon interactions in chiral effective field theory. Furthermore, we demonstrate how next-generation observations of a population of neutron star mergers can offer stringent constraints on three-nucleon couplings, potentially at a level comparable to those from laboratory data. Our work directly connects the microscopic couplings in quantum field theories to macroscopic observations of neutron stars, providing a way to test the consistency between low-energy couplings inferred from terrestrial and astrophysical data.