RUI: Parity Violation in Electron Scattering Experiments at JLab and Nucleon Structure

这笔补助金将支持本科生在一家领先的加速器中心(弗吉尼亚州的托马斯·杰斐逊国家加速器设施)参与尖端实验。这些实验将利用破坏宇称的极化电子散射来研究核子和核结构。极化电子与自旋指向其运动方向和相反方向的散射具有非常微小的不对称性，这使得有助于散射的电磁相互作用和弱相互作用分开。这两种相互作用在核子中感觉到夸克味道，在原子核中感觉到中子和质子，但强度不同。它为详细研究重核表面的核子和中子皮的夸克味道成分提供了可能。测量到的不对称性非常小，需要前所未有的精度，这使得计划中的实验受到目前技术能力的限制。

The grant will support involvement of undergraduate women students in cutting edge experiments in one of the leading accelerator centers (Thomas Jefferson National Accelerator Facility in Virginia). The experiments will utilize parity violating polarized electron scattering to investigate nucleon and nuclear structure. A very tiny asymmetry in the scattering of polarized electrons with spins pointing along their motion and in opposite direction allows the separation of electromagnetic and weak interactions contributing to the scattering. These two interactions sense quark flavors in the nucleon, and neutrons and protons in the nucleus, with different strength. It opens the possibility to study in detail the quark flavor composition of the nucleon and neutron skin on the surface of a heavy nucleus. The measured asymmetry is extremely small and requires an unprecedented precision which puts planned experiments at limits of present technical capabilities.