Majorana中微子的味结构与轻子数破坏效应

一系列令人信服的中微子振荡实验已经确立了中微子具有微小质量以及轻子间具有显著味混合的事实。从理论层面考虑，有质量的中微子更有可能是Majorana粒子，从而导致轻子数破坏的过程发生。确认中微子的Majorana属性是中微子物理学的最重要前沿课题之一。本项目将从如下三个方面开展针对Majorana中微子的深入研究：（1）Majorana中微子质量矩阵的可能结构及其背后潜在的味对称性与对称性破缺机制，以及Majorana相位可能导致的各种CP破坏效应；（2）中微子质量与CP破坏相位对无中微子的双贝塔衰变过程以及其他轻子数破坏过程的影响，以及如何通过针对后者的测量限制甚至确定前者；（3）建立高能标Majorana中微子的模型构造与低能标实验可观测量之间的重整化群演化关系，并研究此类量子效应对味结构本身及其唯象学后果的修正。

The fact that neutrinos are slightly massive and leptons are significantly mixed has been established in a series of convincing neutrino oscillation experiments. From a theoretical point of view, massive neutrinos are most likely the Majorana particles, which can mediate the lepton-number-violating processes. The present research project aims to carry out an in-depth study of the properties of Majorana neutrinos in the following three aspects: (1) Possible structures of the Majorana neutrino mass matrix and underlying flavor symmetries, mechanisms of flavor symmetry breaking and various CP-violating effects; (2) Effects of neutrino masses and CP-violating phases on the neutrinoless double-beta decays and other lepton-number-violating processes, and possible ways to constrain and even determine the former from the latter; (3) A link between model building at high energy scales and low-energy observables via the renormalization-group equations, and impacts of such quantum corrections on flavor issues of Majorana neutrinos and their phenomenological consequences.