QUANTUM CHROMODYNAMICS AND THE SPIN-DEPENDENT QUARK-ANTIQUARK FORCES

Recent results from quantum chromodynamics (QCD) are shown to be consistent with the generalized Breit-type phenomenological Hamiltonian previously proposed for the spin-dependent spectroscopy of quark-antiquark states. In particular, the concept of a short-distance and long-distance quark-gluon chromomagnetic moment, with different qualitative behavior for light and heavy quarks, is compatible with QCD. An induced axial-vector exchange, previously suggested by Feinberg and Sucher, also seems to be implied by the field-theoretic calculations. © 1979 The American Physical Society.