X-ray line signal from 7 keV axino dark matter decay
Physics Letters B 733, 217 (2014)
Jong-Chul Park*, Kyoungchul Kong*, Seong Chan Park
* KU Physics and Astronomy Authors
Recently a weak X-ray emission around Eγ = 3.5 keV was detected in the Andromeda galaxy and various galaxy clusters including the Perseus galaxy cluster but its source has been unidentified. Axino, the superpartner of axion, with a mass 2Eγ is suggested as a possible origin of the line with R-parity violating decay into photon and neutrino. Moreover, most of parameter space is consistent with recent observation by the BICEP2 experiment.