Collaborative Research: Equipment for the PSI MUSE Experiment

合作研究：PSI MUSE 实验设备

• 批准号: 1614850
• 负责人: Evangeline Downie
• 金额: $ 94.04万
• 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: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1614850&HistoricalAwards=false
• 关键词: Collaborative; Research; Equipment; PSI; MUSE

It is well known that protons and neutrons are made from constituents, called quarks and gluons. The quarks and gluons give rise to a finite size of the proton, which is about 10,000 times smaller than the size of a single atom. The goal of this project is to measure the size of the proton. An on-going puzzle is that the proton size appears to be different when measured with atomic hydrogen as compared with its counterpart, called muonic-hydrogen, where the electron in a hydrogen atom is replaced by its heavier cousin, the muon. This project will specifically build equipment to be used in an experiment to provide an independent measurement of the proton radius. In addition to the direct scientific goals of the project, the experiments provide students and young scientists experience and training in working in the international collaborations of modern scientific experiments, with state of the art technology.The seven standard deviation discrepancy between the proton radius measured with muonic hydrogen and with electron-proton scattering may point to physics beyond the standard model of particle physics, or result from novel aspects of conventional physics or from issues in extracting the radius from experimental data. The Muon Scattering Experiment (MUSE) aims to resolve the proton radius puzzle. MUSE uses a mixed pion, muon and electron beam at the Paul Scherrer Institute (PSI) in Switzerland. MUSE will determine the proton radius through both muon-proton scattering and electron-proton scattering, in addition to performing these reactions with positive and negative leptons. This not only reduces systematic uncertainties but also provides sensitivity to two-photon exchange contributions that may be responsible for some of the discrepancies seen in earlier experiments. This collaborative project supports the construction of MUSE over the period September 2016 - August 2018. There will also be ongoing testing and commissioning activities at PSI, including a dress rehearsal run with a partial spectrometer in late 2017. George Washington University is the lead institution (working with Montgomery College) on the computer data acquisition and associated electronics.

众所周知，质子和中子是由选民制成的，称为夸克和胶子。夸克和胶子产生的质子尺寸有限，该质子的大小比单个原子的大小小约10,000倍。该项目的目的是测量质子的大小。 一个持续的难题是，用原子氢测量的质子大小与其对应物（称为Muonic-Hydrogen）进行测量，其中氢原子中的电子被其较重的表弟Muon取代。该项目将专门建造用于实验中的设备，以提供对质子半径的独立测量。除了该项目的直接科学目标外，这些实验还为学生和年轻科学家提供了在现代科学实验的国际合作中的经验和培训。与现代科学实验的国际合作以及最先进的技术。通过Muonic Hydogen测得的质子半径差异差异，用Muonic Hydogen和电子散射与物理学的物理学相比，与物理学相关的物理学的散布可能会导致粒子的物理设备，从而导致物理学的物理学范围，从而提出了粒子的物理设备，以实现粒子的物理学，并将其引起。 数据。 MUON散射实验（MUSE）旨在解决质子半径难题。缪斯（Muse）在瑞士的Paul Scherrer Institute（PSI）中使用混合锥，Muon和Electron Beam。缪斯除了用阳性和阴性瘦素进行这些反应外，还将通过muon-proton散射和电子蛋白散射来确定质子半径。这不仅减少了系统的不确定性，而且还提供了对两光子交换贡献的敏感性，这可能是对早期实验中某些差异的原因。该协作项目支持2016年9月至2018年8月的缪斯的建设。在2017年底，PSI还将进行持续的测试和调试活动，包括与局部光谱仪进行的连衣裙彩排。乔治华盛顿大学是有关计算机数据采集和相关电子设备的领导者（与蒙哥马利学院一起工作）。