Two Loop Neutrino Model and Dark Matter Particles with Global $B-L$ Symmetry

Understand

We study a two loop induced seesaw model with global $U(1)_{B-L}$ symmetry, in which we consider two component dark matter particles.

• The dark matter properties are investigated together with some phenomenological constraints such as electroweak precision test, neutrino masses and mixing and lepton flavor violation.
• In particular, the mixing angle between the Standard Model like Higgs and an extra Higgs is extremely restricted by the direct detection experiment of dark matter.
• We also discuss the contribution of Goldstone boson to the effective number of neutrino species $\Delta N_{\rm eff}\approx0.39$ which has been reported by several experiments.