Quartet Scheme for Elementary Particles

A possible unified model for elementary particles is develpoed generalizing the viewpoint of Sakata-Nagoya model. Instead of the Sakata triplet (p, n and Λ), we work with the quartet of new baryons χ0 and χ(χ1, χ2 and χ3) of spin 1/2, of which χ0 belongs to U(1) whereas the other three to U(3). Strong interactions are subjected to a “broken U(1)×U(3)” symmetry. Baryon octet (N, Σ, Λ and Ξ) and meson octets (K, π, η, K; etc) are interpreted, respectively, as the three (χχχ0)- or two (χχ)-body composite systems both belonging to 8-dimensional representations of SU(3). One of the crucial test of the model is the prediction of triplet mesons (χχ0), the iso-doublet of which can be identified with κ-mesons. The baryon quartet, χ0 and χ, corresponds to four leptons in the sense of “modified” baryon-lepton symmetry. This enables us to explain Cabibbo's phenomenological weak interaction as a consequence of the present scheme.