Speaker
Description
We review the constituent quark model of baryons, as developed in the 1960s by Greenberg and by Dalitz and his collaborators and successors, notably Isgur and Karl, and discuss how this framework can be related to the underlying quark dynamics. We briefly address several developments beyond the simple harmonic-oscillator model, including certain mathematical aspects of the three-body problem in the confinement regime, as well as approximate treatments such as the hypercentral approximation for symmetric or nearly symmetric configurations, and the Born–Oppenheimer description of doubly heavy baryons.
A key issue concerns the coupling to virtual or real decay channels, which transforms otherwise inert three-quark color-singlet configurations into interacting baryons. Another long-standing question is whether the quark-diquark picture, originally proposed by Lichtenberg and subsequently developed by many authors, reflects the genuine underlying dynamics and provides a viable framework for tractable multiquark spectroscopy, or whether it merely constitutes an ad-hoc simplification of the three-body problem, the validity of which has yet to be firmly established.