CAREER: The Three-Dimensional Structure of the Proton

该奖项的全部或部分资金来自《2021年美国救援计划法案》(公法117-2)。质子和中子是几乎所有可见物质的基本组成部分，占可见宇宙质量的95%。质子和中子是由较小的粒子夸克组成的，它们被强大的核力束缚在一起，这种核力由胶子携带，负责从氢离子到中子星的所有核物质。质子和中子内部夸克和胶子的确切排列还不是很清楚。这个项目有助于理解质子和中子中胶子的三维排列。PI使用大规模的超级计算设施来计算质子和中子内部胶子的分布。这些计算补充了由托马斯·杰斐逊国家加速器设施和布鲁克海文国家实验室未来的电子-离子对撞机进行的实验所获得的质子和中子结构数据。PI导师指导学生进行这项研究，正在开发一门关于强核力计算方法的研究生水平课程，并与本科生合作为广大受众创建交互式物理模拟。该项目使用量子色动力学(QCD)的第一原理计算，即强核力理论，计算质子和中子中胶子的三维结构。在与质子和中子结构相关的能量下，QCD是强耦合的，不能用解析方法求解。格子QCD，其中QCD是在离散的格子上形成的，关联函数是用蒙特卡罗方法随机计算的，它提供了一种系统的方法来确定质子、中子和其他强结合粒子的性质。该项目使用晶格QCD计算确定了质子的胶子广义分布函数(GPD)，该函数量化了质子中胶子的三维排列。此外，该项目还将计算胶子和夸克结构之间的关联。这些计算补充了从托马斯·杰斐逊国家加速器设施和布鲁克海文国家实验室未来的电子离子对撞机实验中获得的质子和中子结构的实验数据，并为在一致的框架中结合实验数据和理论数据提供了基础。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。

This award is funded in whole or in part under the America Rescue Plan Act of 2021 (Public Law 117-2). Protons and neutrons are the basic building blocks of almost all visible matter, and account for 95% of the mass of the visible universe. Protons and neutrons are composed of smaller particles, quarks, bound together by the strong nuclear force, which is carried by gluons and is responsible for all nuclear matter, from hydrogen ions to neutron stars. The exact arrangement of quarks and gluons inside protons and neutrons is not well known. This project helps understand the three-dimensional arrangement of gluons within protons and neutrons. The PI uses large-scale supercomputing facilities to calculate the distribution of gluons inside protons and neutrons. These calculations complement data on proton and neutron structure obtained from experiments performed at Thomas Jefferson National Accelerator Facility and the future Electron-Ion Collider at Brookhaven National Laboratory. The PI mentors students carrying out this research, is developing a graduate level course on computational methods for the strong nuclear force, and works with undergraduate students to create interactive physics simulations for a broad audience.This project calculates the three-dimensional structure of gluons within protons and neutrons, by using first principles calculations of quantum chromodynamics (QCD), the theory of the strong nuclear force. At energies relevant to proton and neutron structure, QCD is strongly coupled and cannot be solved analytically. Lattice QCD, in which QCD is formulated on a discrete lattice and correlation functions are computed stochastically using Monte Carlo methods, provides a systematic approach to determining the properties of protons, neutrons, and other strongly-bound particles. The project determines the gluon generalized distribution functions (GPDs) of the proton, which quantify the three-dimensional arrangement of gluons within the proton, using lattice QCD calculations. In addition, the project will calculate correlations between gluon and quark structure. These calculations complement experimental data on proton and neutron structure obtained from experiments at Thomas Jefferson National Accelerator Facility and at the future Electron-Ion Collider at Brookhaven National Laboratory, and provide a basis for combining experimental and theoretical data in a consistent framework.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.