抄録
Using the Nambu-Jona-Lasinio (NJL) model, dynamical chiral-symmetry breaking, light-mesons spectra and properties of the mesons have been investigated on the basis of conventional Hartree-Fock approach. In order to show the advantage of the resonating mean-field theory for a fermion system with large-quantum fluctuations over the usual mean-field theory, we have applied it successfully to the NJL model to describe precisely phenomena associated with pionic excitation. We apply it further to describe more accurately phenomena which associate simaltaneously with pionic and sigma mesonic excitations.
