The projected chiral soliton model with vector mesons

We investigate the solitonic sector of the massive Yang-Mills Lagrangian including σ-, π-, ω-, ρ-, A-mesons as well as valence quarks and apply it to the calculation of some baryonic properties. We perform the canonical quantization which requires the explicit elimination of the time-like components of the vector fields. A mean-field Fock state with hedgehog symmetry is defined as a product of a Slater determinant for the quarks in a 1s-state and coherent states for the mesons. We project this mean-field Fock state onto good spin and isospin by means of Peierls-Yoccoz operators and obtain, after fitting the nucleon mass, a NΔ splitting which is about 80% of the experimental value. A good description of electromagnetic and axial static properties as well as form factors of the nucleon is achieved. Furthermore, the spin content of the nucleon is analyzed in terms of the flavor singlet axial vector coupling constant giving g0A similar 0.44 independently of the input parameters. Finally, the proton-neutron hadronic mass spitting is estimated in the model giving Mn-Mp=2.38±0.55 MeV, the errors reflecting the uncertainty in the up and down quark masses. (orig.)