Probing the Standard Model with Parity-Violating Electron Scattering

用违反宇称的电子散射探测标准模型

• 批准号: 1101818
• 负责人: Mark Pitt
• 金额: $ 44.05万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1101818&HistoricalAwards=false
• 关键词: Probing; Standard; Model; Parity; Violating

This grant supports research that seeks to answer a fundamental question about matter. What is the nature of any new physics not described by the Standard Model of electroweak physics? This question will be addressed by the Qweak experiment at the Thomas Jefferson National Accelerator Facility (TJNAF). It will measure the proton's neutral weak charge via parity-violating electron scattering at very low momentum transfer. The proton's weak charge has a well-defined prediction in the Standard Model; a precise measurement of it is sensitive to many popular scenarios for extending the Standard Model. Our group has built and installed three hardware systems for the experiment - a set of horizontal drift chambers, a set of luminosity monitors, and halo and low beam current monitoring detectors. During the period of this grant, we will maintain our hardware systems during data taking, analyze data, and extract physics results. We will also begin work on a newly approved TJNAF experiment to test the Standard Model - the MOLLER experiment - a precision measurement of the parity-violating asymmetry in the elastic scattering of polarized electrons on unpolarized electrons. The projects we are working on involve a wide range of hardware and software tasks that will contribute to the education of graduate and undergraduate students working on the project.

这项资助支持寻求回答关于物质的基本问题的研究。电弱物理学标准模型没有描述的任何新物理学的本质是什么？这个问题将由托马斯杰斐逊国家加速器设施（TJNAF）的Qweak实验来解决。它将通过在非常低的动量转移下的宇称违反电子散射来测量质子的中性弱电荷。质子的弱电荷在标准模型中有一个明确的预测;对它的精确测量对许多流行的扩展标准模型的方案很敏感。我们的团队已经建立并安装了三个硬件系统的实验-一套水平漂移室，一套光度监测器，和光晕和低束流监测探测器。 在此期间，我们将维护我们的硬件系统在数据采集，分析数据，并提取物理结果。 我们还将开始进行一项新批准的TJNAF实验，以测试标准模型--MOLLER实验--极化电子对非极化电子弹性散射中宇称违反不对称性的精确测量。 我们正在进行的项目涉及广泛的硬件和软件任务，这些任务将有助于研究生和本科生在该项目上的教育。

项目成果

Precision measurement of the weak charge of the proton

• DOI: 10.1038/s41586-018-0096-0
• 发表时间: 2018-05
• 期刊: Nature
• 影响因子: 64.8
• 作者: D. Androić;D. Armstrong;A. Asaturyan;T. Averett;J. Balewski;K. Bartlett;J. Beaufait;R. Beminiwattha-R.-Bemin