Models for Confinement

The distinction between νe and νμ was of course not yet known. B+ must have been thought of as being some boson with lepton number −1 and baryon number 1 (a “leptobaryon”), and clearly it must have been thought to be sufficiently tightly bound to the leptons to escape detection at that time. What kinds of forces could have been responsible for that? The modern versions of our models for baryons and mesons assume them to be composed of quarks. In the 1960s, the arguments used were of the same algebraical nature as those that led Sakata to his model. Then too, the question of the nature of the binding force was posed. When it was assumed that the constituents were strongly charged, and that the binding was caused by the attraction between the charges,2),3) this could only be part of an answer. In contrast with the electromagnetic case, it seems to be impossible to “ionize” hadronic particles: individual quarks are never produced. Why should this be so?