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

本研究计划探讨核子和轻核子系统中强子自由度到夸克-胶子自由度的转变。这将通过研究轻核的短程结构和夸克-强子二象性来实现。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。该项目将有助于国家机构的当前研究，并为俄亥俄州立大学的学生提供培训。原子核的重合电子散射是研究短程结构的典型工具。原子核的许多性质可以用只包含核子、δ和最轻介子的图象来描述。然而，很明显，当一个人进行更小的距离，或更高的能量和动量来探索原子核时，人们会发现一种情况，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，并确定合适的观测值。我还将执行常规核物理基线计算的过程中，人们期望观察到颜色透明度的开始。夸克-强子对偶性表明，在特定的运动区域，强子观测值的适当平均是由一个微扰QCD结果描述的。虽然这一现象在实验上得到了很好的证实，但对对偶现象仍缺乏令人满意的理论解释。对对偶性进行建模并研究它如何在简单模型中产生是理解对偶性最有希望的途径。本项目将继续采用这种方法。我将专注于为对偶极有前途的应用提供必要的理论理解，这将允许从共振数据中提取深层非弹性信息。

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.