Dirac-Fermionic Dark Matter in $U(1)_X$ Models
  We study a number of $U(1)_X$ models featuring a Dirac fermion dark matter
particle. We perform a comprehensive analysis which includes the study of
corrections to the muon magnetic moment, dilepton searches with LHC data, as
well as direct and indirect dark matter detection constraints. We consider four
different coupling structures, namely $U(1)_{B-L}, U(1)_{d-u},
U(1)_{universal}$, and $U(1)_{10+\bar{5}}$, all motivated by compelling
extensions to the standard model. We outline the viable and excluded regions of
parameter space using a large set of probes. Our key findings are that (i) the
combination of direct detection and collider constraints rule out dark matter
particle masses lighter than $\sim 1$ TeV, unless rather suppressed Z'-fermion
couplings exist, and that (ii) for several of the models under consideration,
collider constraints rule out Z' masses up to $\sim 3$ TeV. Lastly, we show
that we can accommodate the recent Diboson excess reported by ATLAS
collaboration within the $U(1)_{d-u}$ model.
