Exploring the light-quark interaction

Abstract

Two basic motivations for an upgraded JLab facility are the needs: to determine the essential nature of light-quark confinement and dynamical chiral symmetry breaking (DCSB); and to understand nucleon structure and spectroscopy in terms of QCD's elementary degrees of freedom. During the next ten years a programme of experiment and theory will be conducted that can address these questions. We present a Dyson-Schwinger equation perspective on this effort with numerous illustrations, amongst them: an interpretation of string-breaking; a symmetry-preserving truncation for mesons; the nucleon's strangeness sigma-term; and the neutron's charge distribution.

Comments: 8 pages, 7 figures. Contribution to the Proceedings of the Workshop on the Physics of the Excited Nucleon (NSTAR2009), Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences, Beijing, 19-22 April 2009