Polarized Electron Scattering from Nucleons and Nuclei

这笔拨款用于支持威廉玛丽学院强子物理小组的研究。该小组利用托马斯·杰斐逊国家加速器设施提供的极化电子束进行实验。这些实验利用了电子散射中“镜像对称”的微小违反，这是由于弱中性电流相互作用的存在而发生的，否则对散射过程的贡献是不明显的。这种“奇偶性破坏”技术被用于探测质子和中子的夸克结构，研究重核中中子的分布（这对理解中子星具有重要意义），以及寻找粒子物理学标准模型之外可能存在的新力或新粒子。该小组负责后一项实验所需的大型线室探测器的设计、建造和测试，该设备已由国家科学基金会主要研究仪器补助金资助。资助博士后1.5名，研究生3名。本科学生的实质性参与也有望通过高级研究项目和REU现场计划在威廉和玛丽。

This grant supports the research of the Hadronic Physics group at the College of William and Mary. The group conducts experiments using the polarized electron beam available at the Thomas Jefferson National Accelerator Facility. These experiments utilize the minute violation of "mirror symmetry" in electron scattering, which occurs due to the presence of the weak neutral-current interaction, an otherwise unnoticeable contribution to the scattering process. This "parity-violation" technique is being used to probe the quark structure of protons and neutrons, to study the distribution of neutrons in a heavy nucleus (which has important implications for understanding neutron stars), and to search for possible new forces or new particles beyond those in the Standard Model of particle physics. The group is responsible for the design, construction and testing of large wire-chamber detectors required for the latter experiment, the equipment for which has been funded by an NSF Major Research Instrumentation grant.The grant supports 1.5 postdoctoral fellows and three graduate students. Substantial involvement of undergraduate students is also anticipated through senior research projects and the REU site program at William and Mary.