2009/06/10 by Eduard Massó, Eduard Masso, Subhendra Mohanty +1 · 115 citations
Physics and Astronomy · #Annihilation #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Dipole #Electric dipole moment #Fermion #MAJORANA #Magnetic dipole #Nucleon #Null (SQL) #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum mechanics #hep-ph
paper · pdf · doi:10.1103/physrevd.80.036009
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 80(3) (American Physical Society) · 23 pages, 8 figures
arxiv created 2009/06/10 · openalex publication_date 2009/08/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
If dark matter (DM) has nonzero direct or transition, electric or magnetic dipole moment then it can scatter nucleons electromagnetically in direct detection experiments. Using the results from experiments like XENON, CDMS, DAMA, and COGENT, we put bounds on the electric and magnetic dipole moments of DM. If DM consists of Dirac fermions with direct dipole moments, then DM of mass less than 10 GeV is consistent with the DAMA signal and with null results of other experiments. If on the other hand DM consists of Majorana fermions then they can have only nonzero transition moments between different mass eigenstates. We find that Majorana fermions with masses 38\ensuremath\lesssimm_\ensuremathχ\ensuremath\lesssim100--200 GeV and mass splitting of the order of (150--200) keV can explain the DAMA signal and the null observations from other experiments and in addition give the observed relic density of DM by dipole-mediated annihilation. The absence of the heavier DM state in the present Universe can be explained by dipole-mediated radiative decay. This parameter space for the mass and for dipole moments is allowed by limits from L3 but may have observable signals at LHC.