US-Germany Cooperative Research: The Crystal Ball at MAMI Project

美德合作研究：MAMI 项目的水晶球

• 批准号: 0341791
• 负责人: Bernard Nefkens
• 金额: $ 2.4万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-01-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0341791&HistoricalAwards=false
• 关键词: US; Germany; Cooperative; Research; Crystal

0341791NefkensThis award supports Bernard Nefkens and students from University of Californis-Los Angeles in a collaboration with Reinhard Beck of the Institute for Nuclear Physics at the University of Mainz, Germany. This award supports a new program of study being undertaken at the Mainz Microtron (MAMI) in Mainz, Germany with the Crystal Ball (CB) detector, the TAPS spectrometer as a forward endcap. Additional equipment includes the Glasgow photon tagger, the Mainz/Bonn polarized target, and the DAPHNE wire chamber. This apparatus will enable a multifaceted physics program involving the measurement of several fundamental quantities related to the structure of the nucleon. Nucleon structure models make specific predictions for not only the masses and decay branching ratios of the states, but also their magnetic moments. The collaboration in Mainz is uniquely situated to measure the magnetic moments of D+(1232) and N+(1535). The only similar previous study is a measurement of uD++(1232) performed at Los Alamos in 1978. The intellectual merit of this program lies in the ability to relate measurements of fundamental quantities such as the magnetic moments of the D(1232) and the N(1535) to the structure of the proton and the neutron, the two basic particles that together make up well over 99% of the visible mass of the known universe. The UCLA group is well qualified to participate in this endeavor, having led an international collaboration using the Crystal Ball detector at the Brookhaven AGS for similar studies with pion and kaon beams. The German group at the Mainz facility plans to devote 2000 hours of beam time per year to this effort over the next five years. The impact of this research will extend far beyond the goals stated in this proposal. In addition to training several physics Ph.D. students engaged in original research projects, this program will contribute to the education of many undergraduate and masters-level students. The Crystal Ball Collaboration has an excellent record of diversity; the students who earned their doctoral dissertations with this detector include not only a woman, but also students from Bangladesh, Thailand, Canada, and Russia. By participating in this program, the various member institutions will enhance their laboratory and data analysis capabilities, thus improving their research and educational infrastructure.

0341791Nefkens 该奖项支持 Bernard Nefkens 和加州大学洛杉矶分校的学生与德国美因茨大学核物理研究所的 Reinhard Beck 合作。 该奖项支持德国美因茨的 Mainz Microtron (MAMI) 开展的一项新研究计划，该项目采用水晶球 (CB) 探测器和 TAPS 光谱仪作为前端盖。 其他设备包括格拉斯哥光子标记器、美因茨/波恩偏振目标和 DAPHNE 线室。 该设备将实现多方面的物理程序，涉及与核子结构相关的几个基本量的测量。 核子结构模型不仅可以对态的质量和衰变分支比进行具体预测，还可以对它们的磁矩进行具体预测。 美因茨的合作在测量 D+(1232) 和 N+(1535) 的磁矩方面具有得天独厚的优势。 之前唯一的类似研究是 1978 年在洛斯阿拉莫斯进行的 uD++(1232) 测量。该程序的智力优点在于能够将 D(1232) 和 N(1535) 磁矩等基本量的测量与质子和中子的结构联系起来，这两种基本粒子共同构成了已知宇宙可见质量的 99% 以上。 加州大学洛杉矶分校小组完全有资格参与这项工作，他们领导了一项国际合作，使用布鲁克海文 AGS 的水晶球探测器对介子和卡介子束进行了类似的研究。 美因茨工厂的德国团队计划在未来五年内每年投入 2000 小时的光束时间来实现这一目标。 这项研究的影响将远远超出本提案中所述的目标。 除了培养数名物理学博士外。学生从事原创研究项目，该项目将为许多本科生和硕士生的教育做出贡献。 Crystal Ball Collaboration 拥有出色的多样性记录；利用该探测器获得博士学位论文的学生中不仅有一名女性，还有来自孟加拉国、泰国、加拿大和俄罗斯的学生。 通过参与该计划，各成员机构将增强其实验室和数据分析能力，从而改善其研究和教育基础设施。