7 keV sterile neutrino dark matter from split flavor mechanism

• DOI: 10.1016/j.physletb.2014.03.044
• Publication Date: 2014-03-26T17:01:18Z
• Authors: Hiroyuki Ishida; Kwang Sik Jeong; Fuminobu Takahashi
• Keywords: Seesaw mechanism; Gravitino; Warm dark matter; Mass generation

The recently discovered X-ray line at about $3.5\,$keV can be explained by sterile neutrino dark matter with mass, $m_s \simeq 7\,$keV, and the mixing, $\sin^2 2\theta \sim 10^{-10}$. Such is more long-lived than estimated based on seesaw formula, which strongly suggests an extra flavor structure in sector. We show that one explain both small mass longevity split mechanism where breaking of symmetry tied to $B-L$ symmetry. In a supersymmetric case we find $7\,$keV implies gravitino $100\,$TeV.