Cosmology and direct detection of the Dark Axion Portal

Understand

The Dark Axion Portal provides a model for Dark Matter (DM) in which both Dark Photons $\gamma^\prime$ and Axions $a$ can contribute to the present day abundance of DM.

• We study the parameter space of the Dark Axion Portal to pinpoint regions of the parameter space where $\gamma^\prime$ and $a$ can be produced with sufficient abundance to account for the cosmic DM density, while still being detectable in planned direct detection and axion haloscope experiments.
• In particular, we explore the production of eV-scale Dark Photons in the Dark Axion Portal, taking into account a possible kinetic mixing between the dark and visible photons, which is essential for the detection of dark photons through absorption in direct searches.
• We show that a non-zero kinetic mixing does not generally spoil the phenomenology of the model, leaving both the axion and dark photon stable.