Direct Detection of Dark Matter Electromagnetic Dipole Moments
  Dark matter candidates with electromagnetic dipole moments can arise as dark
baryons in gauge-mediated or technicolor models. These dark matter candidates
interact with nuclei in direct detection experiments mainly through magnetic
and/or electric dipole moments. The scattering cross sections depend on the
nuclear magnetic moments and nuclear charge and have an infrared enhancement
compared with typical WIMP constant contact interactions, leading to
distinctive nuclear recoil energy spectra. These characteristics result in an
enhanced signal for the DAMA experiment compared with the CDMS or XENON
experiments. The positive results of DAMA, along with the null results of CDMS
and XENON, are consistent with a dark matter particle with magnetic dipole
moment and a mass around ten GeV. Significant direct detection signals can
arise from dipolar dark matter with mass up to of order tens of TeV.
