$\nu_R$ dark matter-philic Higgs for 3.5 keV X-ray signal

Understand

We suggest a new model of 7 keV right-handed neutrino dark matter inspired by a recent observation of 3.5 keV X-ray line signal in the XMM-Newton observatory.

• It is difficult to derive the tiny masses with a suitable left-right mixing of the neutrino in a framework of ordinary simple type-I seesaw mechanism.
• We introduce a new Higgs boson, a dark matter-philic Higgs boson, in which the smallness of its vacuum expectation value can be achieved.
• We investigate suitable parameter regions where the observed dark matter properties are satisfied.