Topics in Strong Force

了解核子的内部结构--质子和中子，我们最熟悉的物质的组成部分--是核物理学的基本挑战之一。这个项目将有助于对量子色动力学（QCD）的新理解，该理论描述了构成核子的夸克和胶子之间的强力。PI将应用理论方法来建立用于理解在托马斯杰斐逊国家加速器设施（JLab）从专注于测量核子性质的实验中获得的实验数据的唯象模型。最近在JLab进行的12 GeV升级将使科学家能够以前所未有的精度研究QCD的性质。教育部分是该项目的一个重要方面。对研究生和本科生的培训和指导将为未来在工业或学术界的职业生涯做好准备。PI的推广活动将通过科普演讲以及对高中生的辅导和指导来提高公众对核粒子物理学的认识。该项目的两个研究领域与强有力的物理学有关，并以广义夸克禁闭问题的唯象和理论方法为基础。该项目的第一个重点是了解对准概率分布敏感的过程的更高扭曲/阶次修正，称为广义Parton分布（GPD），并且对于正确分析实验数据是必不可少的。PI和他的学生将开发一种分离技术，通过提供光子电生截面微分截面的方位角矩的分析公式，从数据中解开GPD。第二个重点是围绕最大超对称杨-米尔斯理论，它占据了杨-米尔斯理论的谐振子的地位，并且是强耦合下解决QCD的核心。理解规范散射振幅，这在两个理论中具有非常相似的微扰展开，是目前追求的规范动力学分析方法的重点。在建立一个形式主义，允许一个解决散射振幅非微扰的一个关键步骤是他们的双重描述威尔逊环的零多边形轮廓，是服从分析技术。

Understanding the internal structure of nucleons -- protons and neutrons, the building blocks of matter that is most familiar to us -- is one of the fundamental challenges in nuclear physics. This project will contribute new understanding to Quantum Chromodynamics (QCD), the theory describing the strong force between the quarks and gluons making up the nucleon. The PI will apply theoretical methods to build phenomenological models used to understand experimental data obtained at the Thomas Jefferson National Accelerator Facility (JLab) from experiments focused on measurements of nucleon properties. The recent 12 GeV upgrade at JLab will allow scientists to study the properties of QCD with an unprecedented level of precision. The educational component represents an important aspect of this project. The training and mentoring of graduate and undergraduate students will prepare junior researchers for future careers in industry or academia. The PI's outreach activities will increase public awareness of nuclear-particle physics through popular science presentations, as well as by mentoring and guidance of high school students.The two research areas of this project are related to the physics of the strong force and are based on phenomenological and theoretical approaches to the problem of quark confinement, broadly defined. The first thrust of the project is focused on understanding of higher twist/order corrections to processes sensitive to quasiprobability distributions, known as Generalized Parton Distributions (GPDs), and will be indispensable for proper analysis of experimental data. The PI and his students will develop a separation technique to disentangle GPDs from data by providing analytical formulas for azimuthal moments of differential cross sections of photon electroproduction cross sections. The second thrust is centered around maximally supersymmetric Yang-Mills theory, which took on the status of the harmonic oscillator of Yang-Mills theories and is central in attempts to solving QCD at strong coupling. Understanding gauge scattering amplitudes, which possess very similar perturbative expansions in the two theories, is the focus of the currently pursued analytical approach to gauge dynamics. A crucial step in establishing a formalism that allows one to address scattering amplitudes nonperturbatively is their dual description in terms of Wilson loops on null polygonal contours that are amenable to analytical techniques.