CAREER: Unravelling the Strong Interaction with High-Energy Nuclear Scattering

原子核几乎占我们周围可见物质的100%。尽管已知原子核受到强相互作用基本理论的约束，但人们还不清楚原子核(以及原子核中的核子)是如何从原子核中出现的。本项目通过对高能轻核反应的理论模拟，研究和提高了我们对强相互作用的认识。这些反应探测轻核的夸克和胶子子子结构，并提供了在自由质子上不可能进行的测量(和相应的计算)。轻核只由几个质子和中子组成，导致反应具有高度的精确度和可控性，并有能力研究核介质对夸克和胶子结构的影响。PI指导在一家少数族裔服务机构从事这项研究的研究生，并参与有高中教师和当地科学博物馆参与的外联活动。为了将教育和研究结合起来，PI还将开发核物理主题的模块，供当地高中生在STEM夏令营使用。这个项目的目标是增进我们对强相互作用的非微扰方面的理论理解，主要是通过电子散射轻核。在高能反应中，电子探测原子核，就像坐在以光速移动的波面上一样。因此，PI和他的学生将使用光波前量子力学的框架，这使得能够将轻核的低能核结构与高能反应动力学完全分开。轻核为探测强相互作用提供了独特的特征：它们可以被极化，从而能够进行与自旋有关的研究；初始核状态在理论和实验上都是众所周知的，可以通过检测核分裂来控制测量。在这个项目中，该团队将利用这些特征在氦和氦上的特定反应中进行。对于极化核，该团队将研究一种新开发的算法的应用，该算法将自旋1/2狄拉克代数推广到更高自旋的情况。这些研究对美国加速器设施的当前和未来测量具有重要意义，例如杰斐逊实验室和布鲁克海文国家实验室未来的电子-离子对撞机。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。

Atomic nuclei make up close to 100% of visible matter around us. Even though it is known that nuclei are bound by the underlying fundamental theory of the strong nuclear interaction, it is not yet understood how exactly they (and the nucleons within them) emerge from it. This project studies and advances our knowledge of the strong interaction through the theoretical modeling of high-energy reactions with light nuclei. These reactions probe the quark and gluon substructure of the light nuclei and give access to measurements (and corresponding calculations) which are not possible on a free proton. Light nuclei consist of only a few protons and neutrons, resulting in reactions with a high degree of precision and control, combined with the ability to study the effect of the nuclear medium on the quark and gluon structure. The PI mentors graduate students working on the research at a minority serving institution and engages in outreach activities involving high-school teachers and the local science museum. In an effort to integrate education and research, the PI will also develop nuclear physics-themed modules to be used at STEM summer camps for local high school students.The goal of this project is to advance our theoretical understanding of non-perturbative aspects of the strong interaction, mainly through electron scattering off light nuclei. In high-energy reactions, an electron probes the nucleus as if sitting on a wave front moving at the speed of light. Hence the PI and his students will use the framework of light-front quantum mechanics, which enables to cleanly separate the low-energy nuclear structure of the light nucleus from the high-energy reaction dynamics. Light nuclei offer unique features to probe the strong interaction: they can be polarized, enabling spin-dependent studies; the initial nuclear state is theoretically and experimentally well known and can be controlled in measurements by detecting nuclear breakup. For this project, the team will exploit these features in specific reactions on the deuteron and helium. For polarized nuclei the team will study applications of a newly developed algorithm which generalizes the spin-1/2 Dirac algebra to higher spin cases. These studies are of importance for current and future measurements at US-based accelerator facilities such as Jefferson Lab and the future electron-ion collider at Brookhaven National Lab.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.