A simplest seesaw model of the TM1 and μ-τ reflection symmetries for the neutrino masses and leptogenesis

Abstract

Abstract In this paper, following the Occam’s razor principle, we have put forward a very simple form of the Dirac neutrino mass matrix M D in the minimal seesaw model with the right-handed neutrino mass matrix being diagonal M R = diag ( M 1 , M 2 ) ; it has one texture zero and only contains three real parameters, whose values can be determined from the neutrino oscillation experimental results. Such a model leads to a neutrino mass matrix M ν ≃ − M D M R − 1 M D T that obeys the TM1 and μ-τ reflection symmetries simultaneously. In this way all the lepton flavor mixing parameters except for θ 13 are predicted; the value of θ 12 is predicted by the TM1 symmetry, while those of θ 23 , δ, ρ and σ by the μ-τ reflection symmetry. And the neutrino masses are predicted to be of the NO case with m 1 = 0 , for which all three light neutrino masses will be pinned down with the help of the experimental results for the neutrino mass squared differences. For these results, the effective Majorana neutrino mass ∣ M ν ee ∣ that controls the rate of the neutrinoless double beta decay is predicted to be 1.6 or 3.8 meV in the case of σ = 0 or π/2. We have also studied the implications of the model for leptogenesis. It turns out that only in the two-flavor leptogenesis regime (which holds in the temperature range 109–1012 GeV) can leptogenesis have a chance to be successful. And a successful leptogenesis can be achieved at M 1 ≃ 1.2 × 10 11 GeV in the case of σ = π/2, but not in the case of σ = 0.