AI. NUCLEAR CONSTITUENTS
Nuclei as Quark Clusters - Quark Chemistry
It turns out that back in 1960, Yoishiro Nambu and Jona-Lasinio developed a model for hadrons, where one starts out with basically zero range interactions, very much like Maria Mayer's idea. But remarkably, they did not have nuclei in mind in their work. Their model in its modern form, generally known as the NJL model, with three quarks per nucleon is turning out to be a remarkably good simple approximation to QCD, at least at low energies. By applying this NJL model to nuclei, it now appears that this model can, in fact, explain many of the things that Maria Mayer discovered empirically, certainly the pairing, and probably also the strong spin-orbit coupling. It appears that there really is some magic in the magic numbers.