Using Effective Operators to Understand CoGeNT and CDMS-Silicon
  Several direct detection experiments have reported positive signals
consistent with a dark matter particle with a mass of approximately 7-9 GeV and
a spin independent scattering cross section of 2.5-4.8 x 10^-41 cm^2. These
results do not rise to the level of discovery, but assuming that they are due
to dark matter, some questions about the underlying physics can already be
addressed. In this paper, I apply the effective operator formalism for dark
matter-Standard Model interactions to the results of the CoGeNT and CDMS
silicon target experiments. I demonstrate that only one set of flavor-blind
effective operators between dark matter can quarks can be consistent with the
reported results in all energy regimes of interest, namely thermal freeze-out,
nuclear scattering, indirect detection, and TeV-scale colliders. This set of
operators implies large couplings of dark matter with heavy quarks. The
alternative implies either that the new physics has non-trivial flavor
structure, that the effective formalism is not applicable and so contains new
states in the spectrum accessible at the LHC, or has large annihilation
channels (possibly via effective operators) into non-colored Standard Model
particles.
