标题： 三种中微子味的振荡与混合 显示英文标题

标题： Oscillation and Mixing Among the Three Neutrino Flavors

摘要： 针对受过教育且感兴趣的非专业读者，我们概述了目前对当代中微子物理的了解和未知之处。 理论告诉我们，中微子是宇宙中第二常见的粒子，仅次于被称为光子的辐射量子。 每秒几乎有万亿个中微子进入每个人的眼球，但我们却看不到它们；这些中微子，数量大致相等，一部分来自我们的太阳，另一部分是早期宇宙热“大爆炸”时代的遗迹。 我们对中微子的了解以及未来希望学到的内容，大部分来自于中微子的一个独特特性——中微子“味”类型的“振荡”。 一种初始的中微子味在传播过程中通常会振荡为另一种味。 振荡是一种量子力学现象。 中微子的奇妙之处在于，它们的量子力学效应可以在大距离上被观测到，甚至可以达到天文学上的距离。 本文首先从质量与混合角的角度介绍中微子现象学，包括三种中微子类型出现的物质-反物质不对称“相”。 接下来我们探讨中微子振荡。 最后我们讨论中微子质量与混合模型的构建。 本文贯穿始终的是对2012年结果的关注，该结果表明“小”的中微子混合角实际上并不那么小。 显示英文摘要

摘要： With the educated, interested non-specialist as the target audience, we overview what is known and not known about contemporary neutrino physics. Theory tells us that neutrinos are the second-most common particle in the Universe, behind only the quanta of radiation called photons. Almost a trillion neutrinos per second enter each human eyeball, and yet we do not see them; these neutrinos, in roughly equal numbers, are emanations from our Sun and relics of the hot "big bang" era of the early Universe. Much of what we know about neutrinos, and hope to learn in the future, is derived from a unique feature of neutrinos -- "oscillation" among neutrino "flavor" types. An initial neutrino flavor will in general oscillate into another flavor as the neutrino propagates in space and time. Oscillations are a quantum mechanical phenomenon. One of the wonders of neutrinos is that their quantum mechanics may be observed over large distances, even astronomically large. We begin this article with neutrino phenomenology in terms of masses and mixing angles, including the matter-antimatter asymmetric "phase" that appears with three neutrino types. Next we venture into neutrino oscillations. We conclude with a discussion of model-building for the neutrino masses and mixings. Throughout this article, attention is devoted to the 2012 result that the "small" neutrino mixing angle is not so small, after all.