If the excess events from the CoGeNT experiment arise from elastic scatterings of a light dark matter off the nuclei, crossing symmetry implies nonvanishing annihilation cross sections of the light dark matter into hadronic final states inside the Galactic halo, which we confront with the antiproton spectrum measured by the PAMELA Collaboration. We consider two types of effective interactions between the dark matter and the quarks: (1) contact interactions from integrating out heavy particles and (2) long-range interactions due to the electromagnetic properties of the dark matter. The lack of excess in the antiproton spectrum results in tensions for a scalar and, to a lesser extent, vector dark matter interacting with the quarks through the Higgs portal.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2010

Higgs in space!

We consider the possibility that the Higgs can be produced in dark matter annihilations, appearing as a line in the spectrum of gamma rays at an energy determined by the masses of the WIMP and the Higgs itself. We argue that this phenomenon occurs generally in models in which the the dark sector has large couplings to the most massive states of the SM and provide a simple example inspired by the Randall-Sundrum vision of dark matter, whose 4d dual corresponds to electroweak symmetry-breaking by strong dynamics which respect global symmetries that guarantee a stable WIMP. The dark matter is a Dirac fermion that couples to a Z{prime} acting as a portal to the Standard Model through its strong coupling to top quarks. Annihilation into light standard model degrees of freedom is suppressed and generates a feeble continuum spectrum of gamma rays. Loops of top quarks mediate annihilation into {gamma}Z, {gamma}h, and {gamma}Z{prime}, providing a forest of lines in the spectrum. Such models can be probed by the Fermi/GLAST satellite and ground-based Air Cherenkov telescopes

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗