Fundamental symmetry tests using low energy neutrons

该奖项将支持低能中子相互作用的时空对称性研究。它试图回答以下问题：a)为什么我们的宇宙是由物质而不是反物质组成的？b)束缚原子核的力之间的相互作用是什么？第一个问题将通过测量中子中电荷的分离来解决，如果时间倒流，这个量将会改变。它涉及到将反物质转化为物质或反之亦然所必需的对称性破坏。我们的贡献是有效地引导离源30米的极化中子进入实验装置。第二个问题探讨了中子在质子上俘获形成氘时所涉及的力。即使强作用力占了7个数量级的优势，弱作用力也会导致我们试图测量的伽马射线产生的不对称分布。这种不对称性将我们的宇宙与镜子反射区分开来，镜子反射的空间方向是相反的。这些实验将有助于解开我们对质子和中子的相互作用和结构的理解。这些项目将对肯塔基大学的本科生和研究生产生重大影响，特别是女性、少数民族和来自阿巴拉契亚地区的学生。这些学生有机会参加洛斯阿拉莫斯国家实验室（LANL）和橡树岭国家实验室（ORNL）的前沿研究。PI正在将这项工作的一部分纳入现代物理学课程，并正在为参与分析这些实验的学生开发科学编程的介绍。为这项研究开发的通用软件库将公开提供。中子导流器的工作将有利于ORNL散裂中子源的后续实验。

This award will support the study of spatial and temporal symmetries in the interactions of low energy neutrons. It seeks to answer the following questions: a) Why is our universe made up of matter but not anti-matter? b) What is the interplay between forces that bind the nucleus? The first question will be addressed by measuring the separation of electric charge in the neutron, a quantity that would change if time ran backwards. It involves the same violation of symmetry necessary to convert antimatter into matter or vice versa. Our contribution is to efficiently guide polarized neutrons thirty meters from the source into the experimental apparatus. The second question explores the forces involved in the capture of neutrons on protons to form deuterium. Even though the strong force dominates by seven orders of magnitude, the weak force would be responsible for an asymmetric distribution in the production of gamma rays, which we seek to measure. This asymmetry distinguishes our universe from a mirror reflection, one with directions in space reversed. These experiments will help unravel our understanding the interactions and structure of protons and neutrons.These projects will have significant effect on undergraduate and graduate students at the University of Kentucky, especially women, minorities, and students from the Appalachian region. These students have the opportunity of participating in cutting-edge research at Los Alamos National Laboratory (LANL) and Oak Ridge National Laboratory (ORNL). The PI is incorporating portions of this work into a course on modern physics, and is developing an introduction to scientific programming for students involved in the analysis of these experiments. General purpose software libraries developed for this research will be made publicly available. The work on neutron guides will benefit subsequent experiments at the Spallation Neutron Source at ORNL.