Quark-Gluon and Hadronic Degrees of Freedom in Few-Body Systems

少体系统中的夸克-胶子和强子自由度

• 批准号: 0139973
• 负责人: Sabine Jeschonnek
• 金额: --
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 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: 2002-09-01 至 2005-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0139973&HistoricalAwards=false
• 关键词: Quark; Gluon; Hadronic; Degrees; Freedom

This research project investigates the transition from hadronic degrees of freedom to quark-gluon degrees of freedom in several systems, both nucleons and light nuclei. This will be done by investigating short-range structure in light nuclei on the one hand, and quark-hadron duality on the other hand. Both parts of the research program are immediately relevant to the experimental program at Jefferson Lab. This project will contribute to current research at a national facility, and provide training for students at The Ohio State University.Coincidence electron scattering from nuclei is the canonical tool for investigating short-range structures. Many properties of nuclei can be described in a picture containing only nucleons, deltas, and the lightest mesons. However, it is clear that when one proceeds to smaller distances, or higher energies and momenta used to explore the nuclei, one will find a situation where the relevant degrees of freedom are no longer the hadrons, but quarks and gluons. Appropriate theoretical tools for disentangling the nuclear ground state information from the data will be developed and tested, and suitable observables will be identified. I will also perform conventional nuclear physics baseline calculations for processes in which one expects to observe the onset of color transparency.Quark-hadron duality states that in certain kinematical regions, the proper average of hadronic observables is described by a perturbative QCD result. While this phenomenon is well established experimentally, a satisfying theoretical explanation of duality is still lacking. Modeling duality and studying how it arises in simple models is the most promising road to understanding duality. This project will continue this approach. I will focus on providing the necessary theoretical understanding for the highly promising applications of duality, which will allow for the extraction of deep inelastic information from resonance data.

本研究计画探讨核子与轻核系统中强子自由度与夸克胶子自由度的转换。这将通过一方面研究轻核的短程结构，另一方面研究夸克-强子对偶性来完成。研究计划的两个部分都与杰斐逊实验室的实验计划直接相关。这个项目将有助于目前在国家设施的研究，并提供培训的学生在俄亥俄州州立大学。符合电子散射从核是典型的工具，研究短程结构。原子核的许多性质可以用一幅只包含核子、δ和最轻的介子的图画来描述。然而，很明显，当我们继续到更小的距离，或者更高的能量和动量来探索原子核时，我们会发现一种情况，在这种情况下，相关的自由度不再是强子，而是夸克和胶子。将开发和测试从数据中分离核基态信息的适当理论工具，并确定适当的可观测量。我也将执行常规的核物理基线计算的过程中，人们期望观察到的色transparency. Quark强子的二重性状态，在某些运动学区域，适当的平均强子观测量描述的微扰QCD结果。虽然这一现象在实验上得到了很好的证实，但仍然缺乏令人满意的理论解释。对二元性进行建模并研究它是如何在简单模型中出现的，这是理解二元性最有前途的道路。本项目将继续采用这一办法。我将专注于提供必要的理论理解的高度有前途的应用程序的对偶性，这将允许深非弹性信息的提取共振数据。