Magnetic inelastic dark matter

Iodine is distinguished from other elements used in dark matter direct detection experiments both by its large mass as well as its large magnetic moment. Inelastic dark matter utilizes the large mass of iodine to allay tensions between the dark matter (DAMA) annual modulation signature and the null results from other experiments. We explore models of inelastic dark matter that also take advantage of the second distinct property of iodine, namely, its large magnetic moment. In such models the couplings are augmented by magnetic, rather than merely electric, interactions. These models provide simple examples where the DAMA signal is compatible with all existing limits. We consider dipole moments for the WIMP, through conventional magnetism as well as dark magnetism, including both magnetic-magnetic and magnetic-electric scattering. We find XENON100 and Cryogenic Rare Event Search with Superconducting Thermometers (CRESST) should generically see a signal although suppressed compared with electric inelastic dark matter models, while Korea Invisible Mass Search (KIMS) should see a modulated signal comparable to or larger than that of DAMA. In a large portion of parameter space, deexcitation occurs promptly, producing a ∼100keV photon inside large xenon experiments alongside the nuclear recoil. This effect could be searched for, but if not properly considered may cause nuclear recoil events to fail standard cuts.