Deep Inelastic Scattering in the Capture of Dark Matter by Neutron Stars

TL;DR

This paper investigates how deep inelastic scattering affects dark matter capture in neutron stars, providing new bounds on DM-nucleon interactions for a broad mass range, which could significantly alter previous constraints.

Contribution

It introduces the calculation of DM-nucleon deep inelastic scattering via a vector mediator and assesses its impact on dark matter capture rates in neutron stars.

Findings

Deep inelastic scattering can dominate over elastic scattering for high-momentum transfer DM.

Inclusion of deep inelastic scattering alters existing bounds on DM-nucleon cross sections.

Bounds for DM masses above 1 GeV are significantly affected by the new calculations.

Abstract

Due to the dense environment, neutron stars (NSs) can serve as an ideal laboratory for studying the interactions between dark matter (DM) and ordinary matter. In the process of DM capture, deep inelastic scattering may dominate over elastic scattering, especially for the DM with a large momentum transfer. In this work, we calculate DM-nucleon deep inelastic scattering via a vector mediator and estimate its contribution to the capture rate. Using the surface temperature of the NSs, we derive the exclusion limits for the DM-nucleon scattering cross section in the mass range, $1~{\rm GeV}<m_{\chi}< 10^{5}~{\rm GeV}$. We find the bounds for DM with the mass $\gtrsim$ 1 GeV can be changed several times after including the deep inelastic scattering contribution.