We propose a scenario in which extra light fermions in an E6-inspired U(1) extension of the standard model constitute the dark matter, as a simple variation of our model for dark radiation presented in 2010. Interestingly, for the light fermions of mass about 7 keV, we naturally obtain a desired mixing angle to explain the recently discovered 3.5 keV X-ray line signal through the radiative decay into active neutrinos and photons with a lifetime in the range of 1027-1028 seconds.
|Number of pages||3|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - 2014 Oct 7|
ASJC Scopus subject areas
- Nuclear and High Energy Physics