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

Smith College, Northampton MA

Investigators

Abstract

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.