Precision Measurements of Fundamental Symmetries and SIDIS

基本对称性和 SIDIS 的精确测量

• 批准号: 1314148
• 负责人: Gerald Feldman
• 金额: $ 36万
• 依托单位: George Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1314148&HistoricalAwards=false
• 关键词: Precision; Measurements; Fundamental; Symmetries; SIDIS

This grant supports research to complete the determination of the weak charge of the proton and investigate new aspects of the Standard Model of fundamental matter and interactions. The Standard Model describes three of the four forces of nature in an elegant manner; those three forces are the electromagnetic interaction, the weak interaction, and the strong interaction. The weak charge of the proton is a basic property, like its electric charge and mass, which determines the proton's response to the weak interaction. It is also related to how the weak and electromagnetic interactions mix with each other. Because the Standard Model predicts how that mixing varies with the amount of momentum that is exchanged in an interaction, a precise measurement of the proton's weak charge at a low value of momentum transfer is a rigorous test of the Standard Model. Additionally, it is sensitive to physics not yet included in the Standard Model. The research program of this award also includes measurements of semi-inclusive deep inelastic scattering that is sensitive to charge symmetry breaking at the quark level and further extends our understanding offundamental interactions.The research group supported by this grant will re-commission the Mott polarimeter at Jefferson Lab. That polarimeter will measure the alignment of electron spins in the electron beam of Jefferson Lab; knowing that alignment is crucial to providing polarized electron beams to the four experimental halls of the Lab. Both hardware and software issues will be addressed in this project so the student and postdoctoral researchers will gain a wide range of valuable skills. These broader impacts on the polarized program of Jefferson Lab and the training of young scientists are interwoven into the research program.

这笔赠款支持完成确定质子弱电荷的研究，并研究基本物质和相互作用标准模型的新方面。标准模型以优雅的方式描述了自然界四种力中的三种：电磁相互作用、弱相互作用和强相互作用。质子的弱电荷象它的电荷和质量一样，是决定质子对弱相互作用响应的基本性质。它还与弱相互作用和电磁相互作用如何相互混合有关。由于标准模型预测了混合如何随着相互作用中交换的动量的量而变化，因此在较低的动量传递值下精确测量质子的弱电荷是对标准模型的严格测试。此外，它对尚未包括在标准模型中的物理特性很敏感。该奖项的研究计划还包括对半包含性深度非弹性散射的测量，该散射对夸克水平上的电荷对称性破坏很敏感，并进一步扩大了我们对基本相互作用的理解。由该拨款支持的研究小组将重新委托杰斐逊实验室的莫特偏振仪。该旋光仪将测量杰斐逊实验室电子束中电子自旋的对准；知道对准对向实验室的四个实验大厅提供极化电子束至关重要。这个项目将解决硬件和软件问题，因此学生和博士后研究人员将获得广泛的有价值的技能。这些对杰斐逊实验室两极分化计划和年轻科学家培训的更广泛影响交织在研究计划中。