Light magnetic dark matter in direct detection searches

We study a fermionic Dark Matter particle carrying magnetic dipole moment and analyze its impact on direct detection experiments. In particular we show that it can accommodate the DAMA, CoGeNT and CRESST experimental results. Assuming conservative bounds, this candidate is shown not to be ruled out by the CDMS, XENON and PICASSO experiments. We offer an analytic understanding of how the long-range interaction modifies the experimental allowed regions, in the cross section versus Dark Matter mass parameter space, with respect to the typically assumed contact interaction. Finally, in the context of a symmetric Dark Matter sector, we determine the associated thermal relic density, and further provide relevant constraints imposed by indirect searches and colliders.
32 pages, 5+1 figures; v2: matches version published on JCAP, dipole-dipole interaction added, discussion on its magnitude added in appendix, few typos corrected and some references added, results strengthened. arXiv admin note: text overlap with arXiv:1108.4661