Measurement of CP-Violation Parameters

认识到解决新物理学的机会，代表20个机构的强有力的合作已经形成，并正在为题为“罕见的对称性违反过程”（RSVP）的项目提供资金。RSVP代表了一个机会，使大学社区做出非凡的重要发现。目前的RSVP项目包括130名科学家，其中约60%来自美国，其他科学家来自加拿大、瑞士、意大利、日本和俄罗斯，沿着100名研究生和博士后。KOPIO是RSVP项目的一个组成部分，是一项测量中性K介子衰变为中性π介子、中微子和反中微子的分支比的实验。这种衰变模式的有趣之处在于，它产生了一个单一的，最深刻的决定参数，描述涉及夸克的CP（或时间反演对称性）破坏。 这反过来将阐明我们的宇宙充满物质的原因，而不是像天真的宇宙起源大爆炸理论所预期的那样，由等量的物质和反物质组成。 这种物质反物质的不对称性，是我们起源的关键因素，也是当今粒子物理学的基本问题之一。

Recognizing an opportunity to address new physics, a strong collaboration representing 20 institutions, has formed and is proposing funding for the project entitled "Rare Symmetry Violating Processes" (RSVP). RSVP represents an opportunity to empower the university community to make discoveries of extraordinary importance. The current scope of RSVP includes 130 scientists, about 60% from the United States, and the others from Canada, Switzerland, Italy, Japan, and Russia, along with an expected 100 graduate students and post-docs.KOPIO, a component of the RSVP project, is an experiment to measure the branching ratio of the decay of a neutral K meson into a neutral pion, a neutrino, and an anti-neutrino. The interest in this decay mode is that it yields the single, most incisive determination of the parameter describing CP (or time reversal symmetry) violation involving quarks. This in turn will shed light on the reason that our Universe is populated with matter, rather than equal amounts of matter and anti-matter as expected from the naive Big Bang theory of the origin of the Universe. This matter anti-matter asymmetry, a critical factor in our origins, is one of the fundamental issues in particle physics today.