  We investigate simplified dark matter models where the dark matter candidate
is a Dirac fermion charged only under a new gauge symmetry. In this context one
can understand dynamically the stability of the dark matter candidate and the
annihilation through the new gauge boson is not velocity suppressed. We present
the simplest Dirac dark matter model charged under the local B-L gauge
symmetry. We discuss in great detail the theoretical predictions for the
annihilation into two photons, into the Standard Model Higgs and a photon, and
into the Z gauge boson and a photon. Our analytical results can be used for any
Dirac dark matter model charged under an Abelian gauge symmetry. The numerical
results are shown in the B-L dark matter model. We discuss the correlation
between the constraints on the model from collider searches and dark matter
experiments.
