Research in Strong-Interaction Theory

要想了解宇宙中物质的形成，需要对原子核有深刻的理解。量子色动力学(QCD)是夸克和胶子的相对论场论，被认为是强力的基本理论，因此也是原子核的理论基础。然而，QCD是极其复杂的，在与描述普通原子核及其成分相关的低能下，很大程度上是无法解决的。提出了从多个角度对这一问题进行攻击的观点。强相互作用的“最简单”束缚系统是核子(质子和中子)和介子，它们是原子核的组成部分。使用俄亥俄州立大学首创的新的光前场理论技术，正在对解决这些系统的QCD进行直接攻击。在普通的核现象中寻找夸克和胶子是一个巨大的挑战。一条从QCD到原子核的路径正在用“有效场论”方法来构建，这种方法用低能粒子对QCD进行了等价但易于处理的描述。与实验的联系是用核反应和结构的相对论描述进行的。这项工作通过提供分析实验的工具来弥合核现象和QCD之间的差距，从而反馈到对原子核及其亚结构的进一步理解。

***9800964Clark Understanding the formation of matter in the universe requires a deep understanding of atomic nuclei. Quantum Chromodynamics (QCD), the relativistic field theory of quarks and gluons, is believed to be the underlying theory of the strong force and therefore of nuclei. However, QCD is extremely complex and is largely unsolved at the low energies relevant for describing ordinary nuclei and their constituents. Attacks on this problem from several perspectives are proposed. The "simplest" bound systems of the strong interaction are nucleons (protons and neutrons) and mesons, of which nuclei are composed. A direct attack on solving QCD for these systems is being mounted using new light-front field theory techniques pioneered at Ohio State. Finding quarks and gluons in ordinary nuclear phenomena is a great challenge. A path from QCD to nuclei is being constructed using "effective field theory" methods, which provide equivalent, but tractable descriptions of QCD in terms of low-energy particles. Contact with experiment is made using relativistic descriptions of nuclear reactions and structure. This work bridges the gap between nuclear phenomena and QCD by providing tools for the analysis of experiments, which then feed back to the further understanding of the nucleus and its substructure.