Applications of a fixed-sphere bag model

Abstract

We extend previous applications of the fixed-sphere MIT bag model to analyses of the nucleon axial radius, spectroscopy of the new heavy hadrons, and weak nonleptonic decays. The nucleon axial-charge radius is calculated to be nearly equal to the electromagnetic-charge radius. Using the ground state of charmonium as input, we predict the masses and excitation energies of new particles. Comparison of the model with observed states reveals that the model has insufficient vector-pseudoscalar mass splitting and inadequate excitation energies. Finally, both $\Delta S=1\mathrm{}$ and $\Delta C=1\mathrm{}$ nonleptonic decays of mesons and baryons are studied using a weak Hamiltonian enhanced by short-distance strong-interaction effects. Variation of matrix elements with the hadronic radius is investigated. The model is found to be unable to reproduce hyperon and kaon decay amplitudes.