Hadron Structure from the Salpeter Equation

The major features of light-flavoured hadronic excitation spectra, from the ground state up to resonances with high total angular momentum at high mass ≈ 3 GeV, can be accounted for in a relativistically covariant quark model, formulated within a field-theoretical framework on the basis of the Bethe-Salpeter equation with instantaneous interaction kernels, containing a confinement potential rising linearly with inter-quark distances and a spin-flavour dependent interaction motivated by instanton effects, that accounts for the most prominent spin-dependent mass splittings observed. It is indicated how this treatment is related to both traditional non-relativistic constituent quark models and other field theoretical approaches.