Selected Problems in Medium Energy Physics

中能物理选题

• 批准号: 0072466
• 负责人: Samuel Danagoulian
• 金额: $ 31.4万
• 依托单位: North Carolina Agricultural & Technical State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0072466&HistoricalAwards=false
• 关键词: Selected; Problems; Medium; Energy; Physics

0072466Danagoulian This proposal requests support for development and interpretation of two experimental programs at Jefferson Lab: neutral pi-meson lifetime precise measurement, experiment "PrimEx" and measurement of the electric and magnetic form factors of the neutron, experiments "Gen". The experiment "PrimEx" will perform a high precision measurement of the lifetime of the neutral pi-meson. The theoretical description of the process of meson decay results in one of the most accurate predictions in QCD, the quantum field theory that describes the properties of the strong interaction between quarks. The present experiment will measure the lifetime with an accuracy of ~1.4% which is consistent with the theoretical uncertainties. It is one of the fundamental experiments in nuclear physics. The neutron is an electrically neutral particle. Nevertheless it possesses an electromagnetic structure. The "Gen" experiments address the fundamental issue of the electromagnetic structure of the neutron by performing precise measurements of the neutron electric and magnetic form factors, Gen and Gmn. The knowledge of the internal structure of the neutron is needed for benchmark calculations in nuclear structure and QCD. Despite its fundamental importance, Gen is still poorly known, and stands as a significant challenge for the experimentalists. Besides its scientific importance the proposed research program will provide our students with unique research opportunities in experimental nuclear physics, and therefore will have a very strong impact on their training and education.

0072466Danagoulian 该提案请求支持杰斐逊实验室两个实验项目的开发和解释：中性 pi 介子寿命精确测量，实验“PrimEx”和中子电磁形状因子的测量，实验“Gen”。实验“PrimEx”将对中性π介子的寿命进行高精度测量。对介子衰变过程的理论描述导致了 QCD 中最准确的预测之一，即描述夸克之间强相互作用特性的量子场论。 本实验将以~1.4%的精度测量寿命，这与理论不确定性一致。它是核物理的基础实验之一。中子是电中性粒子。然而它具有电磁结构。 “Gen”实验通过对中子电和磁形状因子 Gen 和 Gmn 进行精确测量来解决中子电磁结构的基本问题。核结构和 QCD 的基准计算需要了解中子的内部结构。尽管 Gen 具有根本重要性，但它仍然鲜为人知，并且对实验者来说是一个重大挑战。除了其科学重要性之外，拟议的研究计划还将为我们的学生提供实验核物理方面独特的研究机会，因此将对他们的培训和教育产生非常大的影响。