Strange Form Factors, Direct CP Violation, and a Low Energy Standard Model Test

奇怪的外形尺寸、直接 CP 违规和低能耗标准模型测试

• 批准号: 0140059
• 负责人: Mark Pitt
• 金额: --
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-15 至 2009-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0140059&HistoricalAwards=false
• 关键词: Strange; Form; Factors; Direct; CP

The research proposed here seeks the answer to two fundamental questions about matter. The first is what role does the sea of strange quark-antiquark pairs in the nucleon play in the determination of its electromagnetic properties? We are participating in the G0 experiment at Thomas Jefferson National Accelerator Facility to address this issue. The experiment will measure the parity-violating asymmetry in the scattering of polarized electrons from the proton and deuteron over a wide range of momentum transfers;this will allow for the strange electric and magnetic form factors to be separately extracted. This experiment will be in a commissioning and data-taking phase during this grant period. The second question is whether or not there is any new physics beyond the Standard Model of electroweak physics. This question will be addressed by the QWEAK experiment at TJNAF, which will measure the proton's neutral weak charge via parity-violating electon scattering at very low momentum transfer. This proton's weak charge has a well-defined prediction in the Standard Model; a precise measurement of it is sensitive to many poplular scenarios for extending the Standard Model. This experiment will be in a construction phase during this grant period.

这里提出的研究为有关问题的两个基本问题寻求答案。 首先是奇怪的夸克河天对在细胞核中在确定其电磁特性中起着什么作用？ 我们正在托马斯·杰斐逊国家加速器设施参加G0实验，以解决此问题。 该实验将测量质子和迪特隆在各种动量转移中的偏振电子散射中的平均侵略不对称性；这将允许分别提取奇怪的电和磁性颜色。 该实验将在此赠款期间处于调试和数据研究阶段。 第二个问题是，除了Electroweak物理学的标准模型之外，是否还有任何新物理学。 TJNAF的QWEAK实验将解决这个问题，该实验将通过在非常低的动量转移下通过平均侵略的选举散射来测量质子的中性弱电荷。 该质子的弱电荷在标准模型中具有明确的预测。它的精确度量对扩展标准模型的许多poplular方案很敏感。 该实验将在此赠款期间处于建设阶段。