本课题拟从分立味对称来理解费米子的质量等级差与味混合，重点探讨如何从分立味对称解释较大的反应堆中微子混合角 。我们初步打算研究 、 、I'和 等味对称群，建立领头阶能自然地给出扭曲的tribimaximal或Toorop-Feruglio-Hagedorn等轻子混合模式的味模型，讨论模型对无中微子双 beta 衰变、leptogenesis和轻子味破坏等的预言，进一步将味对称性推广到夸克部分。在此基础上，将探讨将分立味对称和大统一理论结合起来，构造具有分立味对称性的费米子质量和味混合的大统一模型。此外，还将尝试寻找与目前实验数据相符的、对应的味对称群较简单的新的轻子混合模式。

In this project, we shall study discrete flavor symmetry to understand the long-standing puzzle of the origin of the fermion mass hierarchy and flavor mixing. We plan to investigate the flavor symmetry group , ,I' and etc, try to build flavor models which can naturally give rise to the so-called deformed tribimaximal or Toorop-Feruglio-Hagedorn mixings in the lepton sector at leading order. Then we discuss the phenomenological predictions for the neutrinoless double beta decay,leptogenesis and the rare lepton flavor violation processes. Furthermore, we extend these discrete flavor symmetries to the quark sector.Based on the above discussion, we shall explore how to combine the discrete flavor symmetry with the grand unification theory, then try to construct grand unification models for fermion mass and flavor mixing with discrete flavor symmetry. Finally we try to propose new leptonic mixing pattern which is in accordance with the present data and the underlying flavor symmetry group is simple enough.