What Does The PAMELA Antiproton Spectrum Tell Us About Dark Matter?

Understand

Measurements of the cosmic ray antiproton spectrum can be used to search for contributions from annihilating dark matter and to constrain the dark matter annihilation cross section.

• Depending on the assumptions made regarding cosmic ray propagation in the Galaxy, such constraints can be quite stringent.
• We revisit this topic, utilizing a set of propagation models fit to the cosmic ray boron, carbon, oxygen and beryllium data.
• We derive upper limits on the dark matter annihilation cross section and find that when the cosmic ray propagation parameters are treated as nuisance parameters (as we argue is appropriate), the resulting limits are significantly less stringent than have been previously reported.