SPHERICAL QUANTUM CHROMODYNAMICS OF HEAVY-QUARK SYSTEMS

We propose a model for quantum chromodynamics, obtained by ignoring th e angular dependence of the gluon fields, which could qualitatively de scribe systems containing one heavy quark. This leads to a two-dimensi onal gauge theory which has chiral symmetry and heavy-quark symmetry. We show that in a light cone formalism, the Hamiltonian of this spheri cal QCD can be expressed entirely in terms of color singlet variables. Furthermore, in the large N(c) limit, it tends to a classical hadron theory. We derive an integral equation for the masses and wave functio ns of a heavy meson. This can be interpreted as a relativistic potenti al model. The integral equation is scale invariant, but renormalizatio n of the coupling constant generates a scale. We compute the approxima te beta function of the coupling constant, which has an ultraviolet st able fixed point at the origin.