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

原子核构成了我们周围几乎100%的可见物质。尽管我们知道原子核是被强核相互作用的基本理论所束缚的，但我们还不知道原子核（以及原子核内部的核子）是如何从强核相互作用中产生的。本项目通过对具有轻核的高能反应的理论建模来研究和推进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结构，并提供了在自由质子上不可能实现的测量（和相应的计算）。轻核仅由少量的质子和中子组成，这使得反应具有高度的精度和可控性，并结合了研究核介质对夸克和胶子结构的影响的能力。PI在少数民族服务机构指导从事研究的研究生，并参与包括高中教师和当地科学博物馆在内的推广活动。为了将教育和研究结合起来，PI还将开发核物理主题模块，用于当地高中生的STEM夏令营。这个项目的目标是推进我们对强相互作用的非摄动方面的理论理解，主要是通过电子从轻核散射。在高能反应中，电子探测原子核，就像坐在以光速运动的波阵面上一样。因此，PI和他的学生将使用光前沿量子力学的框架，它能够将轻核的低能核结构与高能反应动力学清晰地分离开来。轻核提供了独特的特征来探测强相互作用：它们可以极化，使自旋依赖的研究成为可能；初始核状态在理论上和实验上都是已知的，并且可以通过检测核分裂来控制测量。在这个项目中，研究小组将在氘和氦的特定反应中利用这些特征。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的自旋情况。这些研究对于美国的加速器设施，如杰斐逊实验室和布鲁克海文国家实验室未来的电子-离子对撞机的当前和未来的测量具有重要意义。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。

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.