Cosmological Constraints for the Cold Dark Matter and Model Building based on the Flavor Symmetric Radiative Seesaw Model

TL;DR

This paper explores a flavor symmetric radiative seesaw model that constrains neutrino masses and dark matter candidates, providing specific predictions for neutrino mixing, mass spectra, and particle masses consistent with cosmological data.

Contribution

It introduces a dihedral flavor symmetry in a radiative seesaw model, achieving realistic neutrino mixing and suppressed FCNCs, and constrains dark matter particle masses based on cosmological and experimental bounds.

Findings

Maximal atmospheric neutrino mixing achieved.

Inverted neutrino mass spectrum favored.

Dark matter candidate masses constrained between 230 GeV and 750 GeV.

Abstract

It is now clear that the masses of the neutrino sector are much lighter than those of the other three sectors.There are many attempts to explain the neutrino masses radiatively by means of inert Higgses, which don't have vacuum expectation values. Then one can discuss cold dark matter candidates, because of no needing so heavy particles and having a $Z_2$ parity symmetry corresponding to the R-parity symmetry of the MSSM. The most famous work would be the Zee model. Recently a new type model along this line of thought was proposed by Mr. E. Ma. We paid attention to this idea. We introduce a flavor symmetry based on a dihedral group $D_6$ to constrain the Yukawa sector. For the neutrino sector, we find that the maximal mixing of atmospheric neutrinos is realized, it can also be shown that only an inverted mass spectrum, the value of $|V_{MNS_{13}}|$ is 0.0034 and so on. When one extends the Higgs sector, it leads to FCNCs mediated by Higgs fields generally. But in our model, the FCNCs are (of course) suppressed for the experiments sufficiently. For the fermionic CDM candidates, we find that the mass of the CDM and the inert Higgs should be larger than about 230 and 300 GeV, respectively. If we restrict ourselves to a perturbative regime, they should be lighter than about 750 GeV.