Discovering supernova-produced dark matter with directional detectors

TL;DR

This paper proposes using directional detectors to distinguish between supernova-produced MeV-scale dark matter and cosmological WIMP-like dark matter, highlighting the importance of anisotropy in identifying the origin of detected particles.

Contribution

It introduces the concept of using directional detection to differentiate supernova-produced dark matter from traditional WIMP signals based on their anisotropic flux patterns.

Findings

Supernovae can produce MeV-scale dark matter with an anisotropic flux.

Directional detectors can effectively discriminate between supernova-produced and cosmological dark matter signals.

The flux from supernova-produced dark matter is highly peaked towards the Galactic center.

Abstract

Supernovae can produce vast fluxes of new particles with masses on the MeV scale, a mass scale of interest for models of light dark matter. When these new particles become diffusively trapped within the supernova, the escaping flux will emerge semirelativistic with an order-one spread in velocities. As a result, overlapping emissions from Galactic supernovae will produce an overall flux of these particles at Earth that is approximately constant in time. However, this flux is highly anisotropic and is steeply peaked towards the Galactic center. This is in contrast with the cosmological abundance of a WIMP-like dark matter which, due to the rotation of the Galaxy, appears to come from the direction of the Cygnus constellation. In this paper, we demonstrate the need for a directional detector to efficiently discriminate between a signal from a cold cosmological abundance of GeV-scale WIMPs and a signal from a hot population of supernova-produced MeV-scale dark matter.