Galactic constraints on CHAMPs

TL;DR

This paper refines Galactic bounds on the fraction of dark matter composed of charged particles (CHAMPs), especially for those too massive to be detected electromagnetically or to reach Earth, suggesting they can only constitute a tiny fraction of the halo mass.

Contribution

The study provides improved constraints on the abundance of massive CHAMPs in the Galactic halo, considering different halo configurations and decay scenarios.

Findings

CHAMPs can make up less than 0.7% of the Galactic halo mass.

Decaying CHAMPs could potentially address the cuspy halo problem with fine-tuning.

Constraints depend on the halo distribution and CHAMP decay properties.

Abstract

We improve earlier Galactic bounds that can be placed on the fraction of dark matter in charged elemental particles (CHAMPs). These constraints are of interest for CHAMPs whose mass is too large for them to have seen through their electromagnetic interaction with ordinary matter, and whose gyroradius in the galactic magnetic field is too small for halo CHAMPs to reach Earth. If unneutralized CHAMPs in that mass range are well mixed in the halo, they can at most make up a fraction < (3-7) x 10^{-3} of the mass of the Galactic halo. CHAMPs might still be a solution to the cuspy halo problem if they decay to neutral dark matter but a fine-tuning is required. We also discuss the case where CHAMPs do not populate a spherical halo.