Heating Neutron Stars with Inelastic Dark Matter and Relativistic Targets

TL;DR

This paper explores how neutron stars can be used to detect inelastic dark matter by analyzing relativistic scattering processes, potentially surpassing terrestrial detection methods.

Contribution

It develops a relativistic formalism for dark matter capture in neutron stars and demonstrates their sensitivity to inelastic dark matter scenarios beyond current constraints.

Findings

Neutron stars can provide stronger constraints on inelastic dark matter than terrestrial experiments.

The formalism accounts for quasirelativistic dark matter and ultrarelativistic targets in neutron stars.

Neutron stars are sensitive to inelastic self-interacting dark matter parameter space.

Abstract

The dense environment of neutron stars makes them an excellent target for probing dark matter interactions with the Standard Model. We study neutron star heating from capture of inelastic dark matter, which can evade direct detection constraints. We investigate kinematics of the inelastic scattering process between quasirelativistic dark matter particles and ultrarelativistic targets in neutron stars, and derive analytical expressions for the maximal mass gap allowed for the scattering to occur. We implement them into a fully relativistic formalism for calculating the capture rate and apply it to various scenarios of inelastic dark matter. The projected constraints from neutron stars can systematically surpass those from terrestrial searches, including direct detection and collider experiments. Neutron stars can also be sensitive to the parameter space of inelastic self-interacting dark matter. Our results indicate that extreme astrophysical environments, such as neutron stars, are an important target for searching dark matter.