A Model of Realistic Flavor Symmetry: Origin of Fermion Mass, Flavor Mixing and Leptogenesis

Abstract

I proposed a unified model of particle physic and cosmology in \cite {1}, which can simultaneously account for these origin of the inflation, dark energy, dark matter, neutrino mass and baryon asymmetry. I here focus on the fermion flavor issues in the unified model, which were not addressed previously. I introduce a realistic flavor symmetry to generate the fermion mass and mixing, from which we naturally derive the relationship between the quark mixing and the lepton mixing, and reveal the source of the difference between them. In particular, I derive a neutrino mass matrix which has a special structure form and only contains four parameters, but its numerical solutions are exactly accurately fitting to all the measured data of the neutrino mass spectrum and lepton mixing, and finely predict $m_{ν_{2}}=0.01037$ eV. In addition, I discuss a new scenario of the leptogenesis in the model, which arises from two CP-asymmetric decays of a super-heavy neutral Dirac fermion, its CP asymmetry is closely related to the neutrino mass and mixing, via which we can correctly predict the baryon asymmetry. Lastly, I give several approaches to test the model. In short, the model can simply and elegantly account for the fermion flavor issues and the baryon asymmetry, and it has realistic and testable significance, therefore we expect the ongoing and future experiments to test the model.

Figures (2)

• Figure 1: The tree and one-loop diagrams of $N\rightarrow l+H$ and $N\rightarrow\nu_{R}+\phi$. The CP asymmetry of $N\rightarrow l+H$ can generate the lepton asymmetry, while the CP asymmetry of $N\rightarrow\nu_{R}+\phi$ can generate the $\nu_{R}$ asymmetry, these two asymmetries are of the same amounts but opposite signs since the net total lepton number is conserved as zero. Below $T=M_{N}$, the $\nu_{R}$ is shortly decoupled from the primordial plasma, the $\nu_{R}$ asymmetry is forever frozen in the dark sector, whereas the lepton asymmetry in the SM sector is partly converted into the baryon asymmetry through the electroweak sphaleron transition.
• Figure 2: The (a) diagram makes a BSM contribution to the anomalous magnetic moment of the muon. The (b) diagram indicates the pair annihilation of Higgs bosons into a pair of the dark right-handed neutrinos, namely $H+\bar{H}\rightarrow\nu_{R}+\nu_{R}^{c}$ .