Hadronic and Nuclear Structure and Dynamics

Hampton University, Hampton VA

Investigators

Abstract

The goals of this project are to advance the theoretical understanding of hadrons and light nuclei through the application and development of methods broadly based on the concept of effective theories. These effective theories allow for a description of hadronic and nuclear systems preserving a rigorous connection with the fundamental theory of the strong interactions, Quantum Chromodynamics (QCD). One of these studies will address the phenomenology of excited baryons by means of a theoretical framework known as the 1/N expansion of QCD, where N is the number of color degrees of freedom. This plan is of relevance to the current experimental programs on excited baryons at Jefferson Lab and elsewhere. Theoretical studies of some fundamental aspects of the 1/N expansion will also be carried out, especially with focus on the phenomenon of spontaneous breaking of the chiral symmetry in QCD. Another study will address the problem of describing QCD at low and intermediate energies with effective theories. In particular, the project will consider the problem of extending the range of validity of the low energy effective theory of QCD known as Chiral Perturbation Theory to the intermediate energy domain through the inclusion of excited meson states in the effective theory. The application of effective theories to nuclear physics will focus on the study of the low energy expansion of nuclear current matrix elements, in particular electromagnetic currents, for which a large number of phenomenological applications are possible. The project has also an important education component, which includes the training of a PhD student and collaborations with postdoctoral associates.