# Multiscatter stellar capture of dark matter

## TL;DR

This paper analyzes how multiple scatterings of heavy dark matter in stars affect capture rates, revealing new ways to detect high-mass dark matter with very small interaction cross-sections using neutron star temperature measurements.

## Contribution

It provides an analytical framework for multiscatter dark matter capture, expanding detection possibilities for heavy dark matter beyond single-scatter assumptions.

## Key findings

- Multiple scatters significantly increase capture rates for heavy dark matter.
- Neutron star temperature measurements can probe dark matter-nucleon cross-sections below the neutrino floor.
- The parameter space where multiscatter effects are most significant is identified.

## Abstract

Dark matter may be discovered through its capture in stars and subsequent annihilation. It is usually assumed that dark matter is captured after a single scattering event in the star, however this assumption breaks down for heavy dark matter, which requires multiple collisions with the star to lose enough kinetic energy to become captured. We analytically compute how multiple scatters alter the capture rate of dark matter and identify the parameter space where the affect is largest. Using these results, we then show how multiscatter capture of dark matter on compact stars can be used to probe heavy ($m_X >$ TeV) dark matter with remarkably small dark matter-nucleon scattering cross-sections. As one example, it is demonstrated how measuring the temperature of old neutron stars in the Milky Way's center provides sensitivity to high mass dark matter with dark matter-nucleon scattering cross-sections smaller than the xenon direct detection neutrino floor.