arXiv subjects
Publications and source records attributed to Haijun Pan.
We advance a method used to analyse the neutrino properties (masses and mixing) in the seesaw mechanism. Assuming the hierarchical Dirac and light neutrino masses we establish rather simple relations between the light and the heavy neutrino parameters in the favored region of the solar and the atmospheric neutrino experiments. A empirical condition satisfied by the RH mixing angles is obtained.
We study the RH neutrino properties from the low energy neutrino data in the seesaw mechanism. Reonance behavior is found for the right-handed (RH) mixing angle as a function of light neutrino mass ratios in two favored region of the solar neutrino problem and, at the resonance point, the two corresponding RH Majorana neutrino masses are degenerate. This phenomenon is similar with that in the matter-enhanced conversion of neutrinos. The physical significance it infers for the electron neutrino mass and other neutrino parameters is discussed.
As an extension of our previous work in the seesaw mechanism, we analyze the influence of $U_{e3}$ on the properties (masses and mixing) of the RH Majorana neutrinos in three flavors. The quasidegenerate light neutrinos case is also considered. Assuming the hierarchical Dirac neutrino masses, we find the heavy Majorana neutrino mass spectrum is either hierarchical or partial degenerate if $θ_{23}^ν$ is large. We show that degenerate RH Majorana masses correspond to maximal RH mixing angle while hierarchical ones correspond to the RH mixing angles which scale linearly with the mass ratios of the Dirac neutrino masses. An interesting analogue with the behavior of the matter-enhanced neutrino conversion is also presented.