Hadronic and Nuclear Structure and Dynamics

由夸克和胶子理论（QCD）描述的粒子物理标准模型的强相互作用区，呈现出丰富多样的现象，其中最基本的现象有渐近自由、约束和动态手性对称破缺，这些现象决定了强子和原子核的结构和动力学。对这些现象的理解推动了当代重要的实验和理论研究工作，其中研究了各种可观察到的现象和过程，以揭示强相互作用物质的复杂景观。本项目采用有效理论的理论方法，研究重子及其静态和动态特性，这些特性与上述现象和几个实验室目前的实验工作有关。重子是亚原子粒子，如核子或超子。该项目的一个关键目标是开发有效的理论工具，以便更准确地描述低能和中能重子。该项目还投资于研究生和本科生的研究参与，并且由于其在汉普顿大学的位置，它有可能增强理论核物理学的多样性。该项目的目标集中在低能和中能强子的物理研究上，在这些领域中，强相互作用的非摄动性质最为突出。对许多强子观测的理解，如形状因素、电磁极化、低能强子-强子散射、核力等，仍然是一项正在进行的工作，其中有广泛的理论、实验和晶格QCD活动。通过使用有效理论的方法，这些方法严格地锚定在QCD的结构中，在这些领域中描述强子物理是可能的，并且有了它，对不同可观测物之间相互关系的理解成为可能。该计划将集中研究重子，即质子、中子和它们的近亲奇异重子，以及它们的低洼激发态。这将需要进一步发展有效的理论工具，在这种情况下，手性有效理论和1/Nc展开，以及它们在重子观测中的应用，特别是那些尚未被很好理解的，如低能（虚）康普顿散射和相应的极化，电子-核子散射中的单自旋不对称，低能介子-核子散射，以及在重子结构和夸克质量依赖性的晶格QCD计算中得到的结果的应用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The strong interaction sector of the Standard Model of particle physics, described by the theory of quarks and gluons, QCD, presents a rich variety of phenomena, asymptotic freedom, confinement, and dynamical chiral symmetry breaking among the most fundamental ones, which determine the structure and dynamics of hadrons and nuclei. The understanding of those phenomena drives significant contemporary experimental and theoretical research efforts, where a variety of observables and processes are studied in order to shed light onto the complex landscape of strongly interacting matter. Through the application of theoretical approaches known as effective theories, this project aims at studying baryons, their static as well as dynamic properties which are relevant to the mentioned phenomena and to the present experimental efforts at several laboratories. Baryons are subatomic particles, such as nucleons or hyperons. A key objective of the project is to develop the effective theory tools that will permit a more accurate description of baryons at low and intermediate energies. The project is also invested in the research participation of graduate and undergraduate students, and it has the potential to enhance diversity in theoretical nuclear physics through its location at Hampton University. The goals of the project concentrate on the study of the physics of hadrons at low and intermediate energies, domains where the non-perturbative nature of the strong interactions is most prominent. The understanding of many of the hadron observables, such as form factors, electromagnetic polarizabilities, low energy hadron-hadron scattering, nuclear forces, etc, remains a work in progress where there is broad theoretical, experimental and lattice QCD activity. Through the use of the methods of effective theories, which are rigorously anchored in the strictures of QCD, a description of hadronic physics in those domains is possible, and with it an understanding of interrelations between different observables becomes possible. The program will concentrate on the study of baryons, namely protons, neutrons and their cousins the strange baryons, as well as their low lying excited states. It will entail the further development of effective theory tools, in this case chiral effective theory and the 1/Nc expansion, and their applications to baryon observables, in particular those not well understood, such as low energy (virtual) Compton scattering and corresponding polarizabilities, single-spin asymmetries in electron-nucleon scattering, low energy pion-nucleon scattering, and applications to results being obtained in lattice QCD calculations on baryon structure and the dependencies on quark masses.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.