A Model of Metastable EeV Dark Matter

Understand

We propose a model where a long-lived pseudoscalar EeV particle can be produced with sufficient abundance so as to account for the cold dark matter density, despite having a Planck mass suppressed coupling to the thermal bath.

• Connecting this state to a hidden sterile neutrino sector through derivative couplings, induced by higher dimensional operators, allows one to account for light neutrino masses while having a lifetime that can be much larger than the age of the Universe.
• Moreover, the same derivative coupling accounts for the production of dark matter in the very first instant of the reheating.
• Given the sensitivity of the IceCube and ANITA collaborations, we study the possible signatures of such a model in the form of Ultra-High-Energy Cosmic Rays in the neutrino sector, and show that such signals could be detected in the near future.