Not so Coy Dark Matter explains DAMA (and the Galactic Center excess)

Understand

We study a Dirac Dark Matter particle interacting with ordinary matter via the exchange of a light pseudo-scalar, and analyze its impact on both direct and indirect detection experiments.

• We show that this candidate can accommodate the long-standing DAMA modulated signal and yet be compatible with all exclusion limits at $99_S$ % CL.
• This result holds for natural choices of the pseudo-scalar-quark couplings (e.g.~flavor-universal), which give rise to a significant enhancement of the Dark Matter-proton coupling with respect to the coupling to neutrons.
• We also find that this candidate can accommodate the observed 1-3 GeV gamma-ray excess at the Galactic Center and at the same time have the correct relic density today.