KOPIO-Measurement of the Decay K_L -> pi0 + nu + nubar

这项由弗吉尼亚理工学院和州立大学（VT）小组提出的提案旨在为软件和硬件项目提供资金支持，这些项目将能够测量超稀有k介子衰变的分支比，K0L到p0+n+nbar。这种衰变可能是对CP违背的最小标准模型解释的最深刻的检验。要解释为什么宇宙是由物质主导的，需要比目前观测到的更大的CP违逆量。因此，寻找CP违背的外来来源是很重要的。这个被称为KOPIO的实验将在布鲁克海文国家实验室的交替梯度同步加速器上进行，该实验室提供了最强烈的低能长寿命中性k介子光束。VT小组计划用GEANT蒙特卡罗模拟代码维护、更新和回答物理问题，并设计和建造带电粒子和伽马射线探测器，这些探测器将从光束的一般方向发射的背景衰变中捕获粒子。研究计划的更广泛的影响预计将来自于项目中要超越的重要工程问题，以及从高中到研究生院各级学生的参与。

This proposal from the Virginia Polytechnic Institute and State University (VT) group seeks funding for the support of software and hardware projects that will enable a measurement of the branching ratio of the ultra-rare K-meson decay, K0L to p0+n+nbar. This decay is perhaps the single most incisive test of the minimal Standard Model explanation of CP violation. A much larger amount of CP violation than that presently observed is needed to explain why the universe is matter dominated. It is therefore important to search for exotic sources of CP violation. The experiment, called KOPIO, will be carried out at the Brookhaven National Laboratory's Alternating Gradient Synchrotron that provides the most intense beams of low energy long-lived neutral K-mesons. The VT group plans to maintain, update and answer physics questions with the GEANT Monte Carlo simulation code and to design and construct the charged particle and gamma ray veto detectors that will catch particles from background decays emitted in the general direction of the beam.The broader impacts of the research program are expected to derive from the important engineering problems to be surpassed in the project and from the involvement of students at all levels from high school to graduate school.