130 GeV dark matter and the Fermi gamma-ray line

Based on tentative evidence for a peak in the Fermi gamma-ray spectrum originating from near the center of the galaxy, it has been suggested that dark matter of mass similar to 130 GeV is annihilating directly into photons with a cross section similar to 24 times smaller than that needed for the thermal relic density. We propose a simple particle physics model in which the dark matter is a scalar X, with a coupling lambda X-X(2)vertical bar S vertical bar(2) to a scalar multiplet S carrying electric charge, which allows for XX -> gamma gamma at one loop due to the virtual S. We predict a second monochromatic photon peak at 114 GeV due to XX -> gamma Z. The S is colored under a hidden sector SU(N) or QCD to help boost the XX -> gamma gamma cross section. The analogous coupling lambda(h)h(2)vertical bar S vertical bar(2) to the Higgs boson can naturally increase the partial width for h -> gamma gamma by an amount comparable to its standard model value, as suggested by recent measurements from CMS. Due to the hidden sector SU(N) (or QCD), S binds to its antiparticle to form S mesons, which will be pair-produced in colliders and then decay predominantly to XX, hh, or to glueballs of the SU(N) which subsequently decay to photons. The cross section for X on nucleons is close to the Xenon100 upper limit, suggesting that it should be discovered soon by direct detection.