标题： 一种新的类似Wolfenstein的轻子味混合展开，以理解其精细结构 显示英文标题

标题： A new Wolfenstein-like expansion of lepton flavor mixing towards understanding its fine structure

摘要： 以三最大轻子味混合模式作为特定基，我们提出了一种新的方法来展开$3\times 3$幺正的 Pontecorvo-Maki-Nakagawa-Sakata (PMNS) 轻子味混合矩阵$U$，按其最小元素的幅度$\xi \equiv \left|U^{}_{e 3}\right| \simeq 0.149$的幂次展开。这种类似 Wolfenstein 的参数化方式使得$U$能够方便地描述味混合和 CP 违反的显著特征和精细结构，无论是在真空还是在物质中。 显示英文摘要

摘要： Taking the tri-bimaximal flavor mixing pattern as a particular basis, we propose a new way to expand the $3\times 3$ unitary Pontecorvo-Maki-Nakagawa-Sakata (PMNS) lepton flavor mixing matrix $U$ in powers of the magnitude of its smallest element $\xi \equiv \left|U^{}_{e 3}\right| \simeq 0.149$. Such a Wolfenstein-like parametrization of $U$ allows us to easily describe the salient features and fine structures of flavor mixing and CP violation, both in vacuum and in matter.