Collaborative Reseach: Development of a Particle Tracking System for the Qweak Experiment

合作研究：Qweak 实验的粒子跟踪系统的开发

• 批准号: 0320832
• 负责人: Mark Pitt
• 金额: --
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0320832&HistoricalAwards=false
• 关键词: Collaborative; Reseach; Development; Particle; Tracking

Virginia Polytechnic Institute and State University will design andbuild the `Region 2' tracking chambers for the Qweak experiment at Jefferson Lab. This experiment will make a high precision measurement at very low momentum transfer of the proton's weak charge, which is its coupling to the neutral Z boson. A high precision value of the weakmixing angle at low momentum transfer will be extracted, thus providinga sensitive test of the predicted energy scale dependence of this quantityin the electroweak standard model. A failure to observe this expectedbehavior could provide evidence for physics beyond the presently acceptedStandard Model. There are many candidate extensions to the Standard Modelthat would generate observable effects in this experiment. The Region 2 wire chambers are an essential component of the particletracking system, which is needed in order to precisely measure thekinematics of the elastically scattered electrons, as well as forcritical studies of experimental backgrounds. The chambers will consistof two sets of 50 cm x 50 cm horizontal drift chambers. Each drift chamber will have a total of 6 planes of wires. The expected resolutionwill be about 200 microns, providing an angular resolution of 1 mrad. The Region 2 drift chambers will provide quality educational experiencesfor both graduate and undergraduate students. The timescale of the project is well matched to the typical timescale of a graduate student's time in graduate school, so the student will get to participate in all hardware and software phases of the project. The tasks needed to complete the project include design and construction of the chambers, the front-end electronics, and the gas handling system, testing of the finished product, implementation in the Qweak experiment, and data analysis and trackingcode development when the experiment takes data. We expect to involvetwo graduate students and at least two undergraduate students in thiseffort, under the supervision of the faculty and senior research staffat Virginia Tech.

弗吉尼亚理工学院和州立大学将为杰斐逊实验室的 Qweak 实验设计和建造“区域 2”跟踪室。 该实验将以非常低的动量转移对质子的弱电荷（即质子与中性 Z 玻色子的耦合）进行高精度测量。 将提取低动量传递下弱混合角的高精度值，从而为电弱标准模型中该量的预测能量尺度依赖性提供灵敏的测试。 如果未能观察到这种预期行为，可能会为目前公认的标准模型之外的物理学提供证据。 标准模型有许多候选扩展，​​可以在本实验中产生可观察到的效果。 区域 2 线室是粒子跟踪系统的重要组成部分，它是精确测量弹性散射电子的运动学以及对实验背景进行批判性研究所必需的。 这些室将由两组 50 cm x 50 cm 水平漂移室组成。 每个漂移室总共有 6 个平面的电线。 预期分辨率约为 200 微米，提供 1 mrad 的角分辨率。 第二区漂移室将为研究生和本科生提供优质的教育体验。 该项目的时间尺度与研究生在研究生院的典型时间尺度非常匹配，因此学生将参与该项目的所有硬件和软件阶段。 完成该项目所需的任务包括腔室、前端电子设备和气体处理系统的设计和建造、成品测试、Qweak 实验中的实施以及实验获取数据时的数据分析和跟踪代码开发。 我们希望在弗吉尼亚理工大学教师和高级研究人员的监督下，让两名研究生和至少两名本科生参与这项工作。

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