Two-loop Dirac neutrino mass and WIMP dark matter

Understand

We propose a "scotogenic" mechanism relating small neutrino mass and cosmological dark matter.

• Neutrinos are Dirac fermions with masses arising only in two--loop order through the sector responsible for dark matter.
• Two triality symmetries ensure both dark matter stability and strict lepton number conservation at higher orders.
• A global spontaneously broken U(1) symmetry leads to a physical $Diracon$ that induces invisible Higgs decays which add up to the Higgs to dark matter mode.