X-ray Line from the Dark Transition Electric Dipole
Abstract
We study a two-component dark matter (DM) model in which the two Majorana fermionic DM components with nearly degenerate masses are stabilized by an symmetry and interact with the right-handed muon and tau only via real Yukawa couplings, together with an additional -odd singly-charged scalar. In this setup, the decay from the heavy DM to the lighter one via the transition electric dipole yields the 3.55 keV X-ray signal observed recently. The Yukawa couplings in the dark sector are assumed to be hierarchical, so that the observed DM relic abundance can be achieved with the leading s-wave amplitudes without a fine-tuning. We also consider the constraints from flavor physics, DM direct detections and collider searches, respectively.
Keywords
Cite
@article{arxiv.1406.6481,
title = {X-ray Line from the Dark Transition Electric Dipole},
author = {Chao-Qiang Geng and Da Huang and Lu-Hsing Tsai},
journal= {arXiv preprint arXiv:1406.6481},
year = {2014}
}
Comments
16 pages, 4 figures, revised version accepted for publication in JHEP