Testing dark matter with the anomalous magnetic moment in a dark matter quantum electrodynamics model

We consider a model of dark quantum electrodynamics (QEDs) which is coupled to a visible photon through a kinetic mixing term. We compute the gχ − 2 for the dark fermion, where gχ is its gyromagnetic factor. We show that the gχ − 2 of the dark fermion is related to the gχ′− 2 of (visible) QEDs through a constant which depends on the kinetic mixing factor. We determine gχ − 2 as a function of the mass ratio κ = mB/mχ, where mB and mχ denote the masses of the dark photon and the dark fermion, respectively, and we show how gχ − 2 becomes very different for light and heavy fermions around mB ≤ 10−4 eV.