MODELS OF PARTICLE STATES

Two different types of particle state models are discussed. In the fir st type, particles are considered to be dynamically bound systems of a small set of physical constituents. In the second type, particle stat es are constructed from tenser products of ''symmetry constituents,'' i.e., states that are the basis elements of finite irreducible represe ntations of an internal algebra. These states need not represent physi cal particles. We present three models of the first type. For the seco nd type, we discuss in detail the main thrust of this paper, a new ver sion of the quark-lepton model based on the algebra su(4)(color) X su( 6)(flavor). The quark color-triplet and a lepton color-singlet are uni ted by a single irreducible representation of su(4)(color). The su(6)( flavor) algebra is an extension of the original su(3)(flavor). All obs erved ground-state hadron multiplets are in full accord with the predi ctions of this model. The numbers of hadron ground states it predicts are 36 spin-0 mesons, 36 spin-1 mesons, 70 spin-1/2 baryons, and 56 sp in-3/2 baryons.