Galactic constraints on CHAMPs

Understand

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.