Hay Yeung Cheung

After reviewing the minimal SU(2) Skyrme model, we generalize it to a composite model. The predictions are found to be in good agreement with experiment, and an interpretation of solitons as quarks is suggested. To include vector mesons, we propose a lagrangian such that all the mesons (pseudoscalars and vectors) are treated equally. This model agrees with the usual meson physics and gives a new mass relation among the mesons. After reducing the model to an SU(4) Skyrme model, we introduce a soliton ansatz and find the mass spectra of the solitons. The model is compared with the approach of introducing vector mesons as gauge bosons. These two models are shown to coincide at low energies. We propose a fermionic quantization prescription and obtain a hadronic superalgebra from the Skyrme operators. A possible supersymmetry realization and its implications in the Skyrme model are also discussed. The effective hamiltonian of the semi-relativistic quark model is derived. We discuss the mass spectrum and hadronic symmetries of the quark model and the Skyrme model.