Selected Problems in Medium Energy Physics

North Carolina Agricultural & Technical State University, Greensboro NC

Investigators

Abstract

0072466 Danagoulian This proposal requests support for development and interpretation of two experimental programs at Jefferson Lab: neutral pi-meson lifetime precise measurement, experiment "PrimEx" and measurement of the electric and magnetic form factors of the neutron, experiments "Gen". The experiment "PrimEx" will perform a high precision measurement of the lifetime of the neutral pi-meson. The theoretical description of the process of meson decay results in one of the most accurate predictions in QCD, the quantum field theory that describes the properties of the strong interaction between quarks. The present experiment will measure the lifetime with an accuracy of ~1.4% which is consistent with the theoretical uncertainties. It is one of the fundamental experiments in nuclear physics. The neutron is an electrically neutral particle. Nevertheless it possesses an electromagnetic structure. The "Gen" experiments address the fundamental issue of the electromagnetic structure of the neutron by performing precise measurements of the neutron electric and magnetic form factors, Gen and Gmn. The knowledge of the internal structure of the neutron is needed for benchmark calculations in nuclear structure and QCD. Despite its fundamental importance, Gen is still poorly known, and stands as a significant challenge for the experimentalists. Besides its scientific importance the proposed research program will provide our students with unique research opportunities in experimental nuclear physics, and therefore will have a very strong impact on their training and education.