New Constraints from PAMELA anti-proton data on Annihilating and Decaying Dark Matter

TL;DR

This paper uses updated PAMELA anti-proton data to set new limits on dark matter annihilation and decay, refining constraints by considering cosmic ray backgrounds.

Contribution

It provides new constraints on dark matter properties by analyzing anti-proton flux data, including both annihilation and decay scenarios, with and without cosmic ray background considerations.

Findings

No excess anti-protons detected at high energies.

Tighter constraints when including cosmic ray background.

Limits on dark matter annihilation cross-sections and decay lifetimes.

Abstract

Recently the PAMELA experiment has released its updated anti-proton flux and anti-proton to proton flux ratio data up to energies of ~200GeV. With no clear excess of cosmic ray anti-protons at high energies, one can extend constraints on the production of anti-protons from dark matter. In this letter, we consider both the cases of dark matter annihilating and decaying into standard model particles that produce significant numbers of anti-protons. We provide two sets of constraints on the annihilation cross-sections/decay lifetimes. In the one set of constraints we ignore any source of anti-protons other than dark matter, which give the highest allowed cross-sections/inverse lifetimes. In the other set we include also anti-protons produced in collisions of cosmic rays with interstellar medium nuclei, getting tighter but more realistic constraints on the annihilation cross-sections/decay lifetimes.