Experimental Nuclear Physics

The physics of hadrons and nuclei is based on the strong interaction. There are two experimentally verified perturbative quantum field theories that describe nuclear phenomena: perturbative Quantum Chromodynamics (pQCD) at small distances which is governed by gluon fields; and Chiral Perturbation Theory (ChPT) at larger distances which is governed by pion fields. However, the non-abelian nature of the strong interaction gives rise to a non-perturbative "confinement regime" at intermediate distances where more than 98% of the mass of normal matter is generated. A major goal of present day nuclear physics is to understand the connection of the two perturbative regimes and the transition from one to the other. The medium energy nuclear physics group at the University of South Carolina (USC) is devoted to find and carry out the most pressing experiments using electromagnetic probes that broaden our understanding of the nuclear force in the confinement regime. The group's activities are therefore concentrated on in-medium modifications of hadronic properties and baryon spectroscopy. The research program uses multi-GeV photon and electron beams at the Continuous Electron Beam Accelerator Facility (CEBAF) located at the Thomas Jefferson National Accelerator Laboratory (JLab).