Investigations in Intermediate Energy Spin Physics

北卡罗来纳州立大学核物理组正在为杰斐逊实验室的三个主要实验做出贡献：1)SANE实验，E07-003；2)实验E-07-011，高精度测量氚自旋结构函数G1d/F1d？；3)实验E05-101，广角康普顿散射中的初始态螺旋度关联？RCS。这三个实验都探索了质子和氢的自旋结构函数。SANE实验测量了质子在大x处的包含性自旋不对称性，在那里价夸克占主导地位，因此是一个相对干净的区域来研究核子的自旋结构。测量的自旋观测值是理解该区域QCD的基础。QCD是在量子理论框架下描述夸克之间以及质子与中子之间强相互作用性质的量子场论。通过RCS实验测量，初态螺旋度关联不对称性在实际康普顿散射中的统计精度为0.1。康普顿散射是指一定能量的伽马射线光子在电子穿过物质时会反弹，并看到它们的能量减少。这一测量将极大地增强我们将广义部分子分布(GPD)方法应用于真实光子诱导的反应的信心。GPD将著名的费曼部分子分布和核子的电磁形状因子扩展到新的运动学维度。在前向极限下，这些分布简化为费曼部分子分布。另一方面，GPD的一阶矩给出了电磁形状因子。一般而言，GPD包含的核子结构信息比传统的观测数据要丰富得多。所有三个实验都将在C厅进行，并将使用相同的实验设置。NC A&A；T小组已经建造并负责Lucite直视镜，这是实验装置的主要组成部分。该集团还在为升级C厅C12GeV大厅所需的超HMS光谱仪制造石英示波器。北卡罗来纳农工大学是一所历史悠久的黑人大学(HBCU)。拟议的研究计划将为我们的学生提供独特的实验核物理研究机会，因此将对他们的培训和教育产生强烈影响。该项目将允许他们在最先进的设施中工作，并与来自其他国家公认的大学的科学家互动。在这方面，这项建议可以非常有效地吸引非裔美国人和其他代表性不足的群体获得物理学和工程学方面的高级学位，因此将有助于提高核物理领域的多样性。

The NC A&T State University Nuclear Physics group is contributing to three major experiments at Jefferson Laboratory: 1) The SANE experiment, E07-003; 2) experiment E-07-011, ?A High Precision Measurement of the Deuteron Spin-Structure Function g1d/F1d?; and 3) the experiment E05-101, ?Initial State Helicity Correlation in Wide Angle Compton Scattering? RCS. All three experiments explore the spin structure functions of proton and deuterium. The SANE experiment measures inclusive spin asymmetries on the proton at large x, where valence quarks dominate and hence a relatively clean region to study the spin structure of the nucleon. The measured spin observables are fundamental for understanding QCD in that region. QCD is the quantum field theory that describes the properties of the strong interactions between quarks and between protons and neutrons in the framework of the quantum theory. The RCS experiment will measure, the initial state helicity correlation asymmetry in real Compton scattering to a statistical accuracy of 0.1. Compton Scattering is when gamma ray photons of a certain energy will bounce off electrons as they pass through matter, and see their energy decrease. The measurement will significantly increase our confidence in the application of the generalized parton distributions (GPD) approach to reactions induced by real photons. The GPD's extend the well-known Feynman parton distribution and electromagnetic form factors of the nucleon to new kinematic dimensions. In the forward limit, these distributions reduce to the Feynman parton distributions. On the other hand, the first moment of GPD's give the electromagnetic form factors. In general, the GPD's contain much richer structural information of the nucleon than conventional observables. All three experiments will be conducted in Hall C, and will use the same experimental setup. The NC A&T group has built and is in charge of the Lucite Hodoscope, a major component of the experimental setup. The group is also building the quartz hodoscope for the SuperHMS spectrometer needed for the Hall C 12 GeV upgrade in Hall C. North Carolina A&T State University is a historically black university (HBCU). The proposed research program will provide our students with unique research opportunities in experimental nuclear physics, and therefore will have a strong impact on their training and education. The program will allow them to work in a state-of-the-art facility and interact with scientists from other nationally recognized universities. In this respect this proposal can be very effective in attracting African Americans and other underrepresented groups to advanced degrees in physics and engineering and therefore will contribute to greater diversity in the field of nuclear physics.