Form Factors of the Nucleon in a Selfconsistent Chiral Model
  In the present paper we extend the Schwinger model of the nucleon to the inclusion of loop corrections. Starting from a chiral model of nucleon and delta for the mesons $\pi,\rho$ and $A_1$ we extend our nonperturbative sefconsistent regularisation scheme to the calculation of the nucleon form factors. Chiral symmetry requires loops according to the interactions ${\cal L}_{\pi\pi\rho}, {\cal L}_{\rho\rho\rho}, {\cal L}_{\rho\pi A_1}, {\cal L}_{\rho A_1 A_1}$.The coupling constants are strictly introduced by chiral symmetry. The use of low energy theorems and SU(3) relations allow an otherwise parameterfree calculation of the form factors of the nucleon. 
C. Arias Tobena, M.F. Gari