Hadronic Physics for Neutrino-Nucleon Interactions

中微子-核子相互作用的强子物理

• 批准号: 2310149
• 负责人: Emilie Passemar
• 金额: $ 33万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-15 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2310149&HistoricalAwards=false
• 关键词: Hadronic; Physics; Neutrino; Nucleon; Interactions

Modern nuclear and particle physics are concerned with understanding the fundamental parameters and symmetries of nature. Quarks are particles that interact via the strong force, which binds them together in an atomic nucleus. Leptons do not feel this force; the most familiar example of a lepton is the electron that binds to the nucleus by the electromagnetic interaction. A more exotic lepton is the neutrino, which has no electric charge and interacts only weakly.  Yet, this elusive particle is proving to be a crucial link in our search for new physics phenomena. Exquisite experimental measurements over the last two decades revealed that the neutrinos have small but nonzero masses. Today, the field of neutrino physics enters a precision era, with accelerator-based neutrino oscillation experiments taking center stage in the experimental program in the US and in the world. It is hoped that the combined precision data from the quark and lepton sectors will one day provide a key to the nature of the underlying physics. This project provides theoretical foundations needed to support these experimental breakthroughs, in particular, by giving a more rigorous description of neutrino-nucleus interactions. It also serves as an excellent training ground for students. This research focuses on a specific piece of physics that plays a crucial role in modelling neutrino interactions at GeV energies: the nucleon axial form factor. It describes the structure of the nucleon which is not a point-like particle but has a structure that is still not well known. The PI and her collaborators develop an analytical framework to accurately model this form factor, based on the methods of chiral perturbation theory and dispersive techniques. Moreover, a bridge to numerical evaluations on the lattice is established by applications of various analytical constraints, such as current conservation. Agreement with various electron scattering data is also explored. These studies are extended to pion production in neutrino-nucleon scattering where a bridge between the low energy knowledge relying on chiral perturbation symmetry and higher energies needs to be established. This research supports the state-of-the-art nuclear physics experiments at Thomas Jefferson Laboratory, particularly GlueX or CLAS, as well as the upcoming precision neutrino-nucleus scattering experiments at Fermilab and worldwide.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.

现代核物理和粒子物理关注的是理解自然界的基本参数和对称性。夸克是通过强作用力相互作用的粒子，强作用力将它们结合在一起形成原子核。轻子感受不到这种力;最熟悉的轻子例子是通过电磁相互作用与原子核结合的电子。中微子是一种更奇特的轻子，它不带电荷，相互作用很弱。 然而，这种难以捉摸的粒子被证明是我们寻找新物理现象的关键环节。在过去的二十年里，精密的实验测量显示中微子的质量很小，但不为零。今天，中微子物理学领域进入了一个精确的时代，基于加速器的中微子振荡实验在美国和世界的实验计划中占据了中心地位。希望有一天，夸克和轻子扇区的组合精确数据将为基础物理学的本质提供一把钥匙。该项目提供了支持这些实验突破所需的理论基础，特别是通过对中微子-核相互作用进行更严格的描述。它也是学生的一个很好的训练场。 这项研究的重点是一个特定的物理部分，在模拟GeV能量的中微子相互作用中起着至关重要的作用：核子轴向形状因子。它描述了核子的结构，核子不是点状粒子，但其结构仍然不为人所知。PI和她的合作者开发了一个分析框架，以准确地模拟这种形状因子，基于手性微扰理论和色散技术的方法。此外，一个桥梁的数值计算的晶格上建立了各种分析约束，如电流守恒的应用。协议与各种电子散射数据进行了探讨。这些研究扩展到中微子核子散射的π介子生产之间的桥梁依赖于手征微扰对称性和更高的能量需要建立的低能量的知识。这项研究支持了托马斯杰斐逊实验室最先进的核物理实验，特别是GSTX或CLAS，以及费米实验室和全球即将进行的精密中微子核散射实验。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。