Multi-Probe Investigation of the Nucleon

核子的多探针研究

• 批准号: 2310026
• 负责人: Evangeline Downie
• 金额: $ 103.27万
• 依托单位: George Washington University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2310026&HistoricalAwards=false
• 关键词: Multi; Probe; Investigation; Nucleon

Protons, neutrons, and electrons are the building blocks of all matter with which we are most familiar. Despite the scientific efforts to comprehend their nature, there are many things about them that remain to be understood. In 2010, a measurement of the size of the proton gave a much smaller than expected result. This measurement disagreed with, but was much more precise than, all the other proton size measurements to date. Since that time, many other people have tried to re-measure the proton size using different approaches, but the discrepancy persists. The research supported by this award aims to resolve this issue, known as the "Proton Radius Puzzle" by making the first simultaneous measurement of muon and electron scattering on the proton in the Muon Proton Scattering Experiment (MUSE). Through this experiment, in addition to gaining knowledge about protons, the postdoctoral researcher, undergraduate, and graduate students will gain knowledge and experience of modern detection techniques, and simulation and reconstruction software, which are employed in many applications such as industrial or medical imaging. They will also participate in cultural exchanges with researchers from many countries worldwide, and develop their communication, organization, and leadership skills.MUSE will make the world's first measurement of the proton radius via elastic muon scattering at a precision which can address the 4% proton radius puzzle. The experiment will be performed at the Paul Scherer Institute in Switzerland. The simultaneous measurement of elastic e-plus / e-minus and mu-plus/mu-minus scattering on the proton in the MUSE experiment will allow resolution of the proton radius puzzle: the 7-sigma discrepancy between the charge radius of the proton measured in the excitation spectrum of muonic hydrogen and that measured in the excitation spectrum of the atomic hydrogen. Measuring with both electrons and muons simultaneously improves the systematic uncertainty, and provides a test of lepton universality. Measuring both charge states allows for the direct measurement and determination, and then cancellation, of any two-photon effects in both muon- and electron-scattering. This project involves participation in and leadership of data taking and analysis of MUSE through the support of the PI, a graduate student, undergraduate student, and a postdoc. It will result in precise, simultaneous elastic muon and electron scattering data.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.

质子，中子和电子是我们最熟悉的所有物质的基础。尽管有科学的努力来理解其性质，但关于它们的许多事情仍有待理解。在2010年，对质子大小的测量结果比预期的结果要小得多。该测量与迄今为止所有其他质子大小的测量值不同意，但要比所有其他质子大小要精确得多。从那时起，许多其他人试图使用不同的方法重新测量质子的大小，但是差异仍然存在。该奖项支持的研究旨在解决此问题，称为“质子半径拼图”，通过对哑光质子散射实验（MUSE）中的质子进行第一个同时测量哑光和电子散射。通过该实验，除了获得有关质子的知识之外，博士后研究人员，本科和研究生还将获得现代检测技术的知识和经验，以及在工业或医学成像等许多应用中使用的模拟和重建软件。他们还将与来自全球许多国家的研究人员一起参与文化交流，并发展他们的沟通，组织和领导才能。Muse将通过精确地解决4％质子半径拼图的精确度，使世界上首次测量质子半径。该实验将在瑞士的Paul Scherer研究所进行。 The simultaneous measurement of elastic e-plus / e-minus and mu-plus/mu-minus scattering on the proton in the MUSE experiment will allow resolution of the proton radius puzzle: the 7-sigma discrepancy between the charge radius of the proton measured in the excitation spectrum of muonic hydrogen and that measured in the excitation spectrum of the atomic hydrogen.通过电子和兆恩的测量同时可以改善系统的不确定性，并提供了轻子通用性的测试。测量两个电荷状态都可以直接测量和确定，然后取消MUON和电子散射中任何两光子效应。 该项目涉及通过PI，研究生，本科生和博士后的PI的支持参与和领导Muse的数据获取和分析。这将导致精确，同时具有弹性的元音和电子散射数据。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响标准，被认为值得通过评估来获得支持。