Study of the Electro-weak Structure of the Nucleon

该奖项资助的研究计划将提供有关核子结构的实验数据，这些数据可以通过弱相互作用和电磁相互作用来探测。这些目标是通过两个主要项目来实现的，这两个项目计划在获奖期间在杰斐逊实验室获取数据：QWEAK和DVCS/Hall A实验。QWEAK实验是对极低能量尺度下质子弱电荷的精确测量。用粒子物理标准模型预测了质子在不同能量尺度上的弱电荷，它在低能尺度上的精确值对标准模型以外的各种物理过程都很敏感。因此，QWEAK可以提供一种新粒子影响的测量，这将是对大型强子对撞机上的直接观测的补充。DVCS/Hall A实验将研究质子中夸克的动量和空间分布之间的关联。这种关联提供了一种新的方法来研究连接核子研究的两条重要途径的质子：形状因子(空间)分布和部分子分布(动量)函数。该奖项支持的研究小组负责QWEAK的数据采集和数据分析系统，以及DVCS/Hall A实验中的各种硬件和软件项目。这些体验为研究生和本科生提供了绝佳的机会，让他们获得硬件和软件工具的实践经验，并为主要国家实验室的研究做出贡献。

The research program funded by this award will provide experimental data on nucleon structure that can be probed via the weak and the electromagnetic interactions. These objectives are sought through two major projects which are scheduled to take data at Jefferson Lab during the award period: the QWEAK and DVCS/Hall A experiments. The QWEAK experiment is a precision measurement of the weak charge of the proton at very low energy scale. The weak charge of the proton at various energy scales is predicted by the Standard Model of Particle Physics, and its precise value at low energy scale would be sensitive to various physics processes beyond the Standard Model. Thus QWEAK may provide a measure of the influence of new particles which would be complimenatry to the direct observation at the LHC. The DVCS/Hall A experiment will study of the correlation between the momentum and spatial distribution of the quarks within the proton. This correlation provides a novel way to study the proton that bridges between two well explored avenues of nucleon studies: form factor (spatial) distributions and parton distribution (momentum) functions. The research group supported by this award is responsible for the data acquisition and data analysis systems for QWEAK, and for a variety of hardware and software projects within the DVCS/Hall A experiment. These experiements provide outstanding opportunities for both graduate and undergraduate students to get hands-on experience with hardware and software tools and contribute to research at a major national laboratory.