Clark Understanding the formation of matter in the universe requires a deep understanding of atomic nuclei. Quantum Chromodynamics (QCD), the relativistic field theory of quarks and gluons, is believed to be the underlying theory of the strong force and therefore of nuclei. However, QCD is extremely complex and is largely unsolved at the low energies relevant for describing ordinary nuclei and their constituents. Attacks on this problem from several perspectives are proposed. The "simplest" bound systems of the strong interaction are nucleons (protons and neutrons) and mesons, of which nuclei are composed. A direct attack on solving QCD for these systems is being mounted using new light-front field theory techniques pioneered at Ohio State. Finding quarks and gluons in ordinary nuclear phenomena is a great challenge. A path from QCD to nuclei is being constructed using "effective field theory" methods, which provide equivalent, but tractable descriptions of QCD in terms of low-energy particles. Contact with experiment is made using relativistic descriptions of nuclear reactions and structure. This work bridges the gap between nuclear phenomena and QCD by providing tools for the analysis of experiments, which then feed back to the further understanding of the nucleus and its substructure.
