RUI: The Three-Dimensional Momentum and Spin Structure of the Nucleon in QCD

可见宇宙由核子组成：质子、中子和电子。核子本身是部子、夸克和胶子相互作用的动力学系统，是强相互作用的自由度理论，量子色动力学(QCD)。揭示核子的QCD夸克和胶子结构是核物理学的首要任务之一。这个项目的主要目的是推进QCD中核子三维(3D)动量和自旋结构的理论和唯象研究，并绘制以横向动量相关的部分子分布和碎裂函数编码的内部景观。该研究所将通过提供和开发现代统计学和核物理课程，为研究生组织和教授暑期班，以及举办关于核子3D结构的年度讲习班，为培养具有世界级技能的多样化、全球参与的劳动力做出贡献。该项目的科学目标是从现有的实验数据中精确地提取3D核子结构和横向动量相关的分布和碎裂函数。TMD与部分子自旋和运动与核子自旋的关联密切相关，并在散射过程中产生自旋不对称性。该项目旨在统一现有的描述3D核子结构的形式，并最终探索各种过程中自旋不对称的起源。将使用来自过去和现有设施的数据，如Hermes(DESY)、COMPASS(CERN)和Jefferson Lab、Belle(KEK)、BABA(SLAC)、BESIII(北京)、RHIC(BNL)、LHC(CERN)。这项研究将用于建立数据的全局QCD拟合，并统一共线和TMD物理。PI将研究TMD的演变，从实验数据中提取非微扰输入，并将其用于对未来数据的描述和预测。该项目将通过进行现象学和理论研究，提供对当前数据的分析、解释和对未来测量的预测，扩大杰斐逊实验室和布鲁克海文国家实验室现有项目以及美国未来电子离子对撞机的影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The visible universe is made up of nucleons: protons and neutrons, and electrons. Nucleons themselves are interacting dynamical systems of partons, quarks and gluons, the degrees of freedom of the theory of strong interaction, Quantum Chromo Dynamics (QCD). Unfolding the QCD quark and gluon structure of nucleons is one of the highest priorities of nuclear physics. The main objective of this project is to advance theoretical and phenomenological studies of the three-dimensional (3D) momentum and spin structure of the nucleon in QCD and to map its internal landscape encoded in the Transverse Momentum Dependent parton distribution and fragmentation functions. The PI will contribute to the education of a diverse, globally-engaged workforce with world-class skills by providing and developing courses on modern statistics and nuclear physics, organizing and teaching summer schools for graduate students, and running annual workshops on the 3D structure of the nucleon.The scientific goals of this project are to precisely extract the 3D nucleon structure and Transverse Momentum Dependent distribution and fragmentation functions from the existing experimental data. TMDs are intimately related to the correlations of parton spin and motion with the spin of the nucleon and generate Spin Asymmetries in scattering processes. The project is intended to unify existing formalisms of the description of the 3D nucleon structure, and ultimately explore the origin of the Spin Asymmetries in various processes. The data from past and existing facilities, such as HERMES (DESY), COMPASS (CERN), and Jefferson Lab, BELLE (KEK), BaBar (SLAC), BESIII (Beijing), RHIC (BNL), LHC (CERN), will be used. This study will be performed for constructing the global QCD fit of the data and unifying collinear and TMD physics. The PI will study TMD evolution, extract the non-perturbative input from the experimental data and use it for the description and prediction of future data. This project will expand the impact of the existing programs at Jefferson Lab and Brookhaven National Laboratory, and of the future Electron Ion Collider in the USA by performing phenomenological and theoretical studies, providing analysis, explanation of present data, and predictions for future measurements.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.