Mirror and hidden sector dark matter in the light of new CoGeNT data

Abstract

The CoGeNT collaboration has recently made available new data collected over a period of 15 months. In addition to more accurately measuring the spectrum of nuclear recoil candidate events they have announced evidence for an annual modulation signal. We examine the implications of these new results within the context of mirror/hidden sector dark matter models. We find that the new CoGeNT data can be explained within this framework with parameter space consistent with the DAMA annual modulation signal, and the null results of the other experiments. We also point out that the CoGeNT spectrum at low energies is observed to obey $dR/dE_R \propto 1/E_R^2$ which suggests that dark matter interacts via Rutherford scattering rather than the more commonly assumed contact (four-fermion) interaction.