Scattering and Reactions of Intermediate Energy Projectiles

Rutgers University New Brunswick, New Brunswick NJ

Investigators

Abstract

This grant will support the experimental work of the Intermediate Energy Nuclear Physics Group at Rutgers University. The Rutgers group carries out experiments primarily at the continuous electron beam accelerator, CEBAF, located at the Thomas Jefferson National Accelerator Facility in Newport News, Virginia. Their experiments are aimed at improving our understanding of the structure of nucleons. Although we know the basic building blocks of nucleons are quarks and gluons, how they interact to give the nucleon its observed properties is still not well known. Our experiments use spin, a fundamental property of sub-atomic particles, as a sensitive probe of the nucleon. One type of experiment measures the polarization of ejected protons when polarized (spin-aligned) electrons are scattered from nucleons. This determines the distributions of charge and magnetization in the proton, and how those distributions are changed when the proton is bound in a nucleus. Another type of experiments uses polarized photons absorbed on deuterium. The polarization of the outgoing protons is sensitive to the mechanism of the absorption, and hence to the way the quarks and gluons interact in the deuteron. The third major type of experiments use electrons scattered from a polarized helium target to study the quark spin structure of the neutron.