RUI: Test of Chiral Symmetry via the Primakoff Effect

该项目旨在整合杰斐逊实验室正在进行的研究的重要贡献，为有前途的本科生提供教育经验。在过去的四年里，一个由本科生和一名全职教师组成的UNCW小组一直积极参与杰斐逊实验室的研究。该项目的主要目标是优化本科生的经验，同时通过研究三个中性轻赝标介子，π零，eta和eta（eta素数），为我们理解QCD在低能量下的基本性质做出重要贡献。该研究计划包括几个实验，通过Primakoff效应测量这三种粒子的辐射衰减宽度和跃迁形状因子。这些测量的结果将对QCD的基本方面产生重大影响。特别重要的是更准确地确定轻夸克质量比和η-η混合角。这些介子在非常小的动量转移的过渡形状因子将提供模型无关的提取的介子的电磁相互作用半径的大小，和一个低的能量常数的手征Lagrangian.An实验，以测量介子零双光子衰变宽度成功地完成在2004年秋季。目前正在进行数据分析。杰斐逊实验室12 GeV电子束的出现将使测量扩展到eta和eta粒子成为可能。UNCW小组将继续致力于现有的π介子零数据分析，在通过蒙特卡罗模拟优化未来的eta和eta实验装置方面发挥主导作用，并为高能光子标记器的设计和开发以及现有的电磁量能器（HYCAL）升级做出重大贡献。PI还将在Jlab启动一项新的物理工作，以寻找eta-mesic核的束缚态。这项研究将吸引本科科学专业的主要贡献者。本科生的参与已成为UNCW研究小组的标志之一，并符合大学的承诺，提供高质量的本科生学习经验。

This project is designed to integrate important contributions to the ongoing research at Jefferson lab with an educational experience for promising undergraduate students. A UNCW group with a team of undergraduate students and one full time faculty member has been actively involved in Jefferson lab research in the past four years. The primary goal of this project is to optimize the undergraduate experience while making important contributions to our understanding of the fundamental properties of QCD at low energy by studying the three neutral light pseudoscalar mesons, pion-zero, eta and eta (eta-prime). This research program consists of several experiments to measure the radiative decay widths and transition form factors of these three particles via the Primakoff Effect. The results of these measurements will have a significant impact on fundamental aspects of QCD. Of particular importance is a more accurate determination of the light quark-mass ratio and the eta-eta mixing angle. The transition form factors of these mesons at very small momentum transfer will provide model-independent extractions of the size of the electromagnetic interaction radii of mesons, and a low energy constant in the chiral Lagrangian.An experiment to measure the pion-zero two-photon decay width was successfully completed in fall 2004. The data analysis is currently in process. The advent of a 12 GeV electron beam at Jefferson Laboratory will make it possible to extend the measurement to the eta and eta particles. The UNCW group will continue working on existing pion-zero data analysis, play a leading role in optimizing the future experimental setup for the eta and eta by Monte Carlo simulation, and make significant contributions to the design and development of a high energy photon tagger and an existing electromagnetic calorimeter (HYCAL) upgrade. The PI will also initiate a new physics effort at Jlab to search for eta-mesic nuclei bound states. This research will engage undergraduate science majors as key contributors. The involvement of undergraduates has become one of the trademarks of the UNCW research group and matches the universitys commitment to provide a high quality undergraduate learning experience.