While Quantum Chromo-Dynamics (QCD) is understood to govern the interaction of quarks and gluons, the bound states of QCD — protons and neutrons — are unlike bound states associated with any other interactions.
We have a major research program focused on accelerator-based measurements of the quark structure of protons, neutrons and nuclei, as well as short-lived mesons and baryons. This includes major programs of experiments at Jefferson Lab (JLab) and Fermilab, as well as targeted measurements at smaller accelerator facilities around the world.
The program at JLab also studies the interactions of quarks inside nuclei to reveal how quarks interact with the nuclear medium and how they transform from individual quarks to bound mesons and baryons.
We also engage in a major theory effort aimed at understanding how hadrons emerge from QCD. This allows for critical predictions of hadronic properties that can be tested experimentally, and provides tools necessary to interpret experimental data and make direct connections to the underlying structure of matter.