具有整体代对称性的左右对称模型中的中微子质量

本文基于具有整体U(1)代对称性的SU(2)_L×SU(2)_R×U(1)模型推导了轻子的味混合矩阵，对中微子的质量问题进行了研究.在本文的模型中，产生轻子Dirac质量的汤川耦合拉格朗日密度具有整体U(1)代对称性，所以，模型中的带电轻子质量矩阵和中微子Dirac质量矩阵是Fritzsch形式的.但是，中微子除了具有Dirac质量，一般还具有Majorana质量，在这种一般情况下， 关键词： 中微子质量 轻子味混合矩阵 左右对称模型 代对称性

Neutrino masses in the left-right symmetry model with a family symmetry

Based on the SU(2)_L×SU(2)_R×U(1) model with an U<,i>(1) family symmetry, we obtain the lepton flavor mixing matrix and research on the neutrino masses. In the model we consider, the Lagragian density which yields the Dirac masses for the leptons is U(1) family invariant, so both the mass matrix for the charge leptons and the Dirac mass matrix for the neutrinos are of the Fritzsch-type. But, generally speaking, neutrinos may have also Majorana masses. In that situation, the effective mass matrix for the light neutrinos is no longer of the Fritzsch type. We make some assumptions on the phases of the neutrino Majorana mass matrix to avoid diagonalizing the non-hermitian matrix. Then, we obtain the lepton flavor mixing matrix. The numerical calculation which is based on the lepton flavor mixing matrix shows that the model we consider may not fit the present result of the neutrino mixing experiment.