Cosmic Ray Boosted Dark Matter in COSINUS: Modeling and Constraints

TL;DR

This paper models boosted dark matter detection via cosmic ray interactions, providing cross section catalogs and projected constraints for the COSINUS experiment, advancing the search for sub-GeV dark matter.

Contribution

It offers a comprehensive catalog of dark matter-nucleon scattering cross sections and projected experimental constraints for boosted dark matter detection.

Findings

Projected sensitivity of COSINUS to sub-GeV boosted dark matter

Catalog of scattering cross sections for various dark matter and mediator types

Demonstration of detection potential beyond traditional energy threshold limits

Abstract

Direct detection of nuclear recoils due to sub-GeV dark matter is challenging because of the small kinetic energy of the light dark matter particles. Although limits down to a few hundred MeV have been reached using specially designed low threshold detectors, further improvements are now constrained more by background event rates than by energy thresholds. However, constraints down to sub-MeV dark matter masses can still be obtained through the boosted dark matter framework. In this scenario, high-energy cosmic rays or neutrinos scatter off dark matter particles, imparting additional kinetic energy and boosting them beyond the typical velocities expected from the non-relativistic dark matter halo. These boosted dark matter particles can then be detected even by experiments with higher energy thresholds. In this work, we present a catalog of dark matter - nucleon scattering cross sections corresponding to a heavy mediator limit for spin zero, one half and one dark matter and for scalar and vector mediators with even or odd parity. Based on these results, we present projected constraints on the dark matter - nucleon cross section for the COSINUS experiment, assuming an exposure of 100 kg d, demonstrating the potential sensitivity to sub-GeV boosted dark matter.