"It that hath a cloud is more than a parton, and it that hath no cloud is
less than an hadron."
A primary aim of the international program in hadron physics is to explain two fundamental emergent phenomena in physics: quark and gluon confinement; and dynamical chiral symmetry breaking. Neither of these effects is apparent in the action of quantum chromodynamics, the theory which underlies the strong interaction. Nevertheless, they are the key determining characteristics of the hadron spectrum. It is difficult to overestimate the importance of these phenomena. There is strong evidence to suggest that confinement drives dynamical chiral symmetry breaking, and dynamical chiral symmetry breaking is responsible for the fact that the force between nucleons possesses long-range attraction but short range repulsion. Were this not true, the pattern of stable nuclei would be very different indeed and, consequently, the realizable possibilities for life. A contemporary perspective on the theory and phenomenology underlying these aspects of hadron physics will be presented.
ANL Physics Division Colloquium Schedule