Direct Detection of Dark Matter particles with Long Range Interaction

We study the effect of a long-range DM-nuclei interaction occurring via the exchange of a light mediator. We consider the main direct detection experiments: DAMA, CoGeNT, CRESST, CDMS and XENON100. We find that a long-range force is a viable mechanism, which can provide full agreement between the various experiments, especially for masses of the mediator in the 10-30 MeV range and a light DM with a mass around 10 GeV. The relevant bounds on the light mediator mass and scattering cross section are then derived.