The Extended Chiral Quark Model in a Tamm-Dancoff Inspired Approximation

A procedure inspired by the Tamm-Dancoff method is applied to the chiral quark model which has been extended to include additional degrees of freedom: a pseudoscalar isoscalar field as well as a triplet of scalar isovector fields. The simpler, generic $\sigma$ -- model has been used before as a test for the Tamm-Dancoff inspired approximation (TDIA). The extended chirial quark model is employed here to investigate possible novel effects of the additional degrees of freedom as well as to point out the necessesity to introduce a SU(3) flavour. Model predictions for the axial-vector coupling constant and for the nucleon magnetic moment obtained in TDIA are compared with experimental values.