How Topological Concepts Lead to Quantum Numbers for Baryons

Abstract

Strong interaction physics is currently believed to be determined by quantum chromodynamics. If this is correct, then it follows that all of nuclear physics must, somehow, be a consequence. Unravelling these consequences will be a daunting task, for nuclear physics is the regime of longdistances (on the scale of Λ_QCD) and it is precisely here that the enormously strong confinement forces will be operative. A direct approach, starting from QCD, is not presently known, but strong hints as to the nature of the confinement regime have come from ft Hooftfs idea of taking the number of colors (N_c) in QCD to be large¹. Assuming confinement, the result²is an effective field theory of colorless low-lying mesons, without explicit quarks. Baryons become extended objects and involve topological concepts applied to non-linear self-interacting meson fields.

Supported in part by the National Science Foundation

Alexander von Humboldt Stiftung Re-Invitation Program on leave from Duke University, Durham, NC 27706 USA.