Updated Collider and Direct Detection Constraints on Dark Matter Models
  for the Galactic Center Gamma-Ray Excess
  Utilizing an exhaustive set of simplified models, we revisit dark matter
scenarios potentially capable of generating the observed Galactic Center
gamma-ray excess, updating constraints from the LUX and PandaX-II experiments,
as well as from the LHC and other colliders. We identify a variety of
pseudoscalar mediated models that remain consistent with all constraints. In
contrast, dark matter candidates which annihilate through a spin-1 mediator are
ruled out by direct detection constraints unless the mass of the mediator is
near an annihilation resonance, or the mediator has a purely vector coupling to
the dark matter and a purely axial coupling to Standard Model fermions. All
scenarios in which the dark matter annihilates through $t$-channel processes
are now ruled out by a combination of the constraints from LUX/PandaX-II and
the LHC.
