SU3-INVARIANT SPINOR THEORY WITHOUT QUARKS

A phenomenological spinor theory is developed which incorporates SU3 symmetry in the form of octet spinor fields rather than triplet quark fields. This allows the use of more conventional procedures in attacking the dynamical problem. A development of such a SU3 theory based on Weyl spinors proves too restrictive, since, in particular, it is unable to produce a nontrivial F/D ratio for the 0--boson-octet-baryon interaction in the lowest approximation. Hence the main emphasis is based on theories involving Dirac spinor fields. It is demonstrated that in the octet formulation the Weyl-type V-A interaction is the only four-spinor interaction which has exactly SU3×SU3 as maximal internal symmetry group (besides the two gauge groups). The SU3×SU3 invariant interactions involving Dirac-scalar terms have higher symmetry. For theories involving among others a scalar interaction an appropriate regularization procedure allows one to formulate the continuity equations for the currents in the conventional form. Mass values and coupling constants for the simplest baryon and boson multiplets can be calculated in terms of one free regularization constant. There exists a uniquely determined SU3-breaking four-spinor interaction which is proportional to an octet operator and does not mix SU3 multiplets. The formalism is exemplified in some preliminary models. © 1969 Società Italiana di Fisica.