WIMP Dark Matter within the dark photon portal

Abstract

We test the dark photon as a portal connecting to the dark sector in the case of Dirac fermion and complex scalar dark matter with masses up to 1 TeV. Both the dark photon and the $Z$ boson contribute to the dark matter annihilation and dark matter--nucleon scattering processes. We derive the lower limits on the dark parameters from thermal relic density. The corresponding spin-independent dark matter--proton cross sections are compared with the upper bounds set by direct detection. We explore the allowed regions of the dark parameter space that are consistent with these constraints.