Lining up the Galactic Center Gamma-Ray Excess
  Dark matter particles annihilating into Standard Model fermions may be able
to explain the recent observation of a gamma-ray excess in the direction of the
Galactic Center. Recently, a hidden photon model has been proposed to explain
this signal. Supplementing this model with a dipole moment operator and a small
dark sector mass splitting allows a large cross section to a photon line while
avoiding direct detection and other constraints. Comparing the line and
continuum cross sections, we find that the line is suppressed only by the
relative scales and couplings. Given current constraints on this ratio, a line
discovery in the near future could point to a new scale Lambda ~ O(1 TeV),
where we would expect to discover new charged particles. Moreover, such a line
would also imply that dark matter can be visible in near-future direct
detection experiments.
