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 g(x) - 2 for the dark fermion, where g(x) is its gyromagnetic factor. We show that the g(x)- 2 of the dark fermion is related to the g(x)'- 2 of ( visible) QEDs through a constant which depends on the kinetic mixing factor. We determine g(x)-2 as a function of the mass ratio k = m(B)/m., where m(B) and m(x) denote the masses of the dark photon and the dark fermion, respectively, and we show how g(x) - 2 becomes very different for light and heavy fermions around m(B) <= 10(- 4) eV.