Sensitivity of Neutron Star Observations to Three-nucleon Forces

TL;DR

This paper evaluates how current and future neutron star observations, especially gravitational wave data, can constrain the strength of three-nucleon forces, which are crucial for understanding dense nuclear matter.

Contribution

It introduces a Bayesian framework to assess the sensitivity of gravitational wave observations to three-nucleon forces in dense matter, highlighting the potential of third-generation detectors.

Findings

Current detectors can constrain three-nucleon forces in high SNR, low-mass systems.

Third-generation detectors will significantly improve constraints on three-body interactions.

Neutron star observations can serve as laboratories for nuclear physics.

Abstract

Astrophysical observations of neutron stars have been widely used to infer the properties of the nuclear matter equation of state. Beside being a source of information on average properties of dense matter, however, the data provided by electromagnetic and gravitational wave (GW) facilities are reaching the accuracy needed to constrain, for the first time, nuclear dynamics in dense matter. In this work we assess the sensitivity of current and future neutron star observations to directly infer the strength of repulsive three-nucleon forces, which are key to determine the stiffness of the equation of state. Using a Bayesian approach we focus on the constraints that can be derived on three-body interactions from binary neutron star mergers observed by second and third-generation of gravitational wave interferometers. We consider both single and multiple observations. For current detectors at design sensitivity the analysis suggests that only low mass systems, with large signal-to-noise ratios (SNR), allow to reliably constrain the three-body forces. However, our results show that a single observation with a third-generation interferometer, such as the Einstein Telescope or Cosmic Explorer, will constrain the strength of the repulsive three-body potential with exquisite accuracy, turning third-generation GW detectors into new laboratories to study the nucleon dynamics.