Neutron stars at the dark matter direct detection frontier

TL;DR

Neutron stars can serve as sensitive detectors for dark matter, with their heating effects providing stronger constraints on dark matter interactions than terrestrial experiments, especially for spin-dependent and velocity-suppressed scattering.

Contribution

This paper introduces a novel method using neutron star heating to probe dark matter interactions, surpassing terrestrial detection limits for certain scattering types.

Findings

Neutron star heating can set stronger limits on dark matter interactions than terrestrial experiments.

The sensitivity is particularly high for spin-dependent and velocity-suppressed scattering.

Effective operator cutoff limits are significantly improved for dark matter heavier than a GeV.

Abstract

Neutron stars capture dark matter efficiently. The kinetic energy transferred during capture heats old neutron stars in the local galactic halo to temperatures detectable by upcoming infrared telescopes. We derive the sensitivity of this probe in the framework of effective operators. For dark matter heavier than a GeV, we find that neutron star heating can set limits on the effective operator cutoff that are orders of magnitude stronger than possible from terrestrial direct detection experiments in the case of spin-dependent and velocity-suppressed scattering.