Theoretical Studies of Medium- and high-energy Electron Scattering off Light Nuclei

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由强相互作用的基本理论所束缚的，但我们还不清楚它们（以及其中的核子）是如何从强相互作用中产生的。本项目将通过轻核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。轻核只由几个核子组成，导致反应具有高度的精确性和控制性。在这些系统中，强相互作用既可以在不同核子之间进行研究，也可以在单个核子内部进行研究，在单个核子内部，强相互作用于基本夸克和胶子构建块。PI将指导研究生从事这项研究，开发核物理研究生课程，并参与包括高中教师在内的外联活动。该项目的目标是通过电子散射轻核来推进我们对强相互作用的非微扰方面的理论理解。 在高能反应中，一个电子探测原子核，就像坐在一个以光速移动的波前上一样。因此，PI和他的合作者将使用光前沿量子力学的框架，这使得人们能够将轻核的低能核结构与高能反应动力学完全分离。 轻核提供了探测强相互作用的独特功能：它们可以被极化，使自旋相关的研究成为可能;初始核状态是众所周知的，可以在测量中控制。 在这个项目中，PI将在氘和氦的反应中利用这些特征。这些研究对美国加速器设施（如杰斐逊实验室和未来的电子离子对撞机）的当前和未来测量具有重要意义。该奖项反映了NSF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's 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 will study and advance our knowledge of the strong interaction through the theoretical modeling of high-energy reactions with light nuclei. Light nuclei consist of only a few nucleons, resulting in reactions with a high degree of precision and control. In these systems, the strong interactions can be studied both between different nucleons and within a single nucleon, where it acts on the fundamental quark and gluon building blocks. The PI will mentor graduate students working on the research, develop a graduate course in nuclear physics, and engage in outreach activities involving high-school teachers.The goal of this project is to advance our theoretical understanding of non-perturbative aspects of the strong interaction 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 collaborators will use the framework of light-front quantum mechanics, which enables one 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 well known and can be controlled in measurements. For this project, the PI will exploit these features in reactions on the deuteron and helium. 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.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.