Extension of the Skyrme model and the strangeness problem

The author discusses the static properties of the soliton which exists in the effective chiral Lagrangian of pseudoscalar and vector mesons which incorporate the non-abelian anomaly structure of QCD. Also he introduces a scalar glueball to mock up the scale anomaly of QCD and considers its coupling to the quarkonium scalar particle and possible mixing between them. He examines the resulting bag formation of the glueball due to the soliton and the physical properties of the soliton. He also explains how to introduce external gauge particles in this scheme and studies the general minimal symmetry breaking structure in the soliton model systematically. In the Skyrme model, he points out that the role the η (SU(2)singlet) particle is subtle. It survives during collective rotation due to the vector meson sources. It changes the static energy and the other physical properties slightly but provides an explanation for the proton-neutron mass difference and for the non-vanishing value of the quark contribution to the proton spin. In the neutron-proton mass difference case the terms including η are the dominant ones but he needs a small SU(3) contribution in addition. In the proton spin problem he adopts a Lagrangian including a pseudoscalar glueball which mocks up the U(1) axial anomaly. He finds that there is a small contribution to the U(1) axial current matrix element in the proton state which is equivalent to the proton spin due to the current quarks. He investigates the detailed structure of the SU(3) Skyrme model in the collective quantization scheme which was greatly improved by Yabu and Ando recently by doing exact diagonalization of the Hamiltonian instead of using the first order perturbation theory