1 INTRODUCTION

Theoretical models for the structure of the nucleons and the hyperons are constructed for the purpose of obtaining an understanding of the dynamics that gives rise to their complex spectra. The most modest goal is to explain the ground state energies and thecorresponding static observables magnetic moments and rms radii. More ambitious models attempt in addition to explain the dynamic observables as, e.g., the electromagnetic form factors, which requires that not only overall features are understood, but that at least some parts of the short-range dynamics are understood as well.

The rich structure of the baryon spectrum, with 5 known successive flavor generations [the nucleons (up and down quarks), the strange, the charmed and the bottom hyperons] makes the construction of a realistic nucleon model a complex task. Naturally, if it were possible, one would like to take the Lagrangian density of quantum chromodynamics as the starting point. This is formed of quark and gluon field operators. While the mass scale of the baryons is 1 GeV, that of the light u and d quarks and the gluons is essentially 0 ( m _u ? 5 MeV, m _d ? 8 MeV, m _gluon = 0). That baryons with masses of the order of 1 GeV or more can be formed of such light constituents is a consequence of the very strong gluon exchange interaction at low energies.

The running coupling constant...