A Theoretical Study of Hadronic Interactions and the Structure of the Nucleon

这项续签提案要求美国国家科学基金会继续资助一项研究计划，该计划目前由国家科学基金会-物理-0070368拨款支持。提出的主要课题在夸克核物理领域，以研究强相互作用粒子的夸克亚结构。特别关注QCD的近似对称性，特别是偏爱和电荷对称性。对称性破坏为识别和量化非微扰物理提供了一面镜子。这项研究应该揭示物质基本成分的详细性质，重点是偏爱和电荷对称性的有效性，部分子分布的自旋依赖，以及部分子性质的核修改。这项授权的一个成果将是对低能和高能电荷对称性的全面回顾，强调我们目前对上下夸克质量差在各种能量和物理过程中产生电荷对称性破坏的作用的理解。PI开发的模型将用于研究最近的中微子结果，这些结果被建议显示出超越标准模型的物理学。重子共振的结构将通过一个专门为研究这些系统而开发的相对论代码来研究。这些计算的新特征应该允许更真实地描述.25N系统中的共振结构。还建议研究与量子线和光子晶体相关的约束二维系统中粒子的结合和散射。先前在这一领域的研究在斯普林格-维拉格出版的一本专著中达到了顶峰。继续研究包括与一位实验同事合作，将新几何的理论研究与在这些系统上的实验相结合。在所有拟议的领域中，理论和实验之间有着密切的联系。最近PI的一些预测正在LEP、HERA和Tevatron等设备上进行研究。这里提出的重子共振工作与在杰斐逊实验室的Clas探测器上获得的数据有关。PI参与了一种可能的新设施--电子-离子对撞机(EIC)的研究，该设施在最近的NSAC核物理长期计划中得到了积极的评估。PI是最近EIC规划工作的合著者，其中包括一个网站和包含EIC物理白皮书的CD-ROM。PI是印第安纳大学核理论中心(NTC)的主任。目前，全国过渡委员会有四名博士后和来访者，其中三名是女性。在若干情况下，在全国过渡委员会工作的妇女得到了来自两个或更多来源的联合支助，包括联邦、大学或外国捐款。国际和平研究所促进了NTC与澳大利亚、日本和德国的物理研究所之间的国际合作。在过去的8年里，国际和平研究所在夏季REU项目中指导了9名本科生研究人员。他们在随后的研讨会和专业会议上发表了关于他们的研究的演讲，并与PI合作出版了出版物。这里提出的研究将为博士后研究助理和物理专业本科生提供培训和指导。

This renewal proposal requests continued NSF funding of a research program currently sup-ported by the grant NSF-PHY-0070368. The major proposed topics lie in the area of \quark{nuclear physics," to study the quark sub{structure of strongly interacting particles. Particularattention is on approximate symmetries of QCD, particularly favor and charge symmetry.Symmetry violation provides a \mirror" to identify and quantify non-perturbative physics.This research should shed light on the detailed properties of the fundamental constituents ofmatter, with emphasis on the validity of favor and charge symmetry, the spin dependenceof parton distributions, and nuclear modification of parton properties. One product of thisgrant would be a comprehensive review of charge symmetry at both low and high energies,emphasizing our current understanding of the role of the up-down quark mass difference ingenerating charge symmetry violation over a wide variety of energies and physical processes.Models developed by the PI will be employed to investigate recent neutrino results, which aresuggested to show physics beyond the Standard Model. The structure of baryon resonanceswill be investigated through a relativistic code developed explicitly to study these systems.New features of these calculations should allow a more realistic description of the structure ofresonances in the .25N system. It is also proposed to study binding and scattering of particlesin constrained 2-D systems, relevant to quantum wires and photonic crystals. Prior research inthis area culminated in a monograph published by Springer-Verlag. Continuing studies involvecollaboration with an experimental colleague combining theoretical studies of novel geometrieswith experiments on these systems.In all proposed areas, there is close linkage between theory and experiment. Some recentpredictions by the PI are being studied at facilities such as LEP, HERA and the Tevatron.The baryon resonance work proposed here is relevant to data taken at the CLAS detectorat Jefferson Lab. The PI is involved in studies for a possible new facility, an Electron-IonCollider (EIC), which was favorably assessed in the recent NSAC Long-Range Plan for nuclearphysics. The PI is a co-author on recent EIC planning efforts that include a Web site and CD-ROM containing a Whitepaper on EIC physics. The PI is Director of the Indiana UniversityNuclear Theory Center (NTC). Currently the NTC has four postdocs and visitors, three ofwhom are women. In several instances, women working at NTC have received joint supportfrom two or more sources, combining federal, university or foreign contributions. The PI hasset up international collaborations between the NTC and physics institutes in Australia, Japanand Germany. The PI has mentored 9 undergraduate researchers in summer REU programsduring the past 8 years. They have given talks on their research at subsequent workshopsand professional meetings, and have collaborated on publications with the PI. The researchproposed here will provide training and mentoring for both postdoctoral research associates,and undergraduate physics majors.