(An) experimental test of various colored triplet and quartet quark models

Abstract

In this note, the ``Color`` symmetry is first introduced in quark model and it is shown how the various quark models with color symmetry can explain the problems in nonrelativistic quark model such as the spin statistcs problem in SU(6) theory, integral charge assignment, triality puzzle, exotics puzzle, and diquark puzzle. And the interaction Hamiltonian proportional to $\lambda_1-\lambda_2$ which can explain three kinds of puzzle is derived from the gauge invariant quark-gluon interaction Lagrangian based on the color symmetry group. Next the color symmetry in quark model is extended to models with charm quark. Here we also show that the Weinberg-Salam model which uses these extended models as hadronic part is free from Adler-Bell-Jsckiw anomaly. It is also shown that $\pi^o \rightarrow 2 \gamma$ decay amplitude favors the colored triplet (quartet) quark models over one triplet (quartet) model. Finally for determining which scheme among various colored quark models is physically the most plausible, four experimental data are compared with predictions from various models. In comparisons parton model is assumed and quarks from various models are assumed to be partons. First the experimental data for $R = \frac{\sigma(e^+e^- \rightarrow {hardrons})}{\sigma(e^+ e^-\rightarrow \mu^+ \mu^-)}$ are compared with predictions. The ratio $T = \frac{\sigma(e^+ e^- \rightarrow e^+ e^-hadrons)}{\sigma(e^+ e^- \rightarrow e^+ e^- \mu^+ \mu^-)}$ of two photon process is also derived from various models for future reference. Next inelastic Compton scattering data of proton are compared with predictions. The data for electroproduction sum rules and the ratio $$\frac{\nu w_2^{neutron}}{\nu w_2^{proton}}$$ are compared, too. From the comparisons, it can be concluded that the integrally charged colored quark models (SUB model, Han-Nambu model) are more plausible than the fractionally charged one (Gell-Mann``s Colored quark model) if we believe the Lipkin``s symmetric argument.