The recently discovered X-ray line at about 3.5keV can be explained by sterile neutrino dark matter with mass, m s ≃ 7keV, and the mixing, sin22θ ~ 10 -10. Such sterile neutrino is more long-lived than estimated based on the seesaw formula, which strongly suggests an extra flavor structure in the seesaw sector. We show that one can explain both the small mass and the longevity based on the split flavor mechanism where the breaking of flavor symmetry is tied to the breaking of the B - L symmetry. In a supersymmetric case we find that the 7keV sterile neutrino implies the gravitino mass about 100TeV.
|Number of pages||5|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - 2014 May 1|
ASJC Scopus subject areas
- Nuclear and High Energy Physics