Nonabelian dark matter models for 3.5 keV X-rays

Understand

A recent analysis of XXM-Newton data reveals the possible presence of an X-ray line at approximately 3.55 keV, which is not readily explained by known atomic transitions.

• Numerous models of eV-scale decaying dark matter have been proposed to explain this signal.
• Here we explore models of multicomponent nonabelian dark matter with typical mass ~ 1-10 GeV (higher values being allowed in some models) and eV-scale splittings that arise naturally from the breaking of the nonabelian gauge symmetry.
• Kinetic mixing between the photon and the hidden sector gauge bosons can occur through a dimension-5 or 6 operator.