QCD forces and heavy quark bound states

The present knowledge of QCD confining forces between static test charges is summarised, with an emphasis on lattice results. Recent developments in relating QCD potentials to quarkonium properties by use of effective field theory methods are presented. The validity of non-relativistic QCD and the adiabatic approximation with respect to heavy quark bound states is explored. Besides the static potential and relativistic correction terms, the spectra of glueballs and gluinoballs, hybrid excitations of the QCD flux tube between fundamental colour sources, potentials between charges in various representations of the SU(3) gauge group, and multi-particle interactions are discussed. Some implications for quarkonia systems and quark–gluon hybrid mesons are drawn.