On short range effects in nucleon structure

A chiral bag model is considered in which the confinement radius coincides with the chiral invariance spontaneous breaking radius. In the interior range, where the quarks are massless, the valence quark contribution is taken into account as well as the quark bag vacuum polarization by the external chiral field on the bag surface. The exterior range, where the quark mass is large (Mq → ∞), is described by the QCD effective chiral Lagrangian. A stable solution of this model corresponds to a large bag: fR ∼ 0.6, 0.98<gA<1.18. The results are compared with a version of the model in which the exterior range is described by Skyrme chiral Lagrangian