ON THE CONSISTENCY OF EFFECTIVE MODELS OF NUCLEON STRUCTURE WITH CHIRAL SYMMETRY

In this paper we show that the transparent SU6 relation between the axial charge couplings G(A) and G(A)DELTA of the n --> p, and n --> DELTA+ weak transitions, respectively, allows us to control consistency with chiral symmetry of effective nucleon structure models within an accuracy comparable to that of the Adler-Weisberger sum rule. We derive a slightly modified expression for the (G(A)DELTA/G(A))2-ratio in terms of nucleons helicity and the axial charge coupling of the weak transition from the nucleon to the Roper resonance instead of the phenomenological mixing angle. We interpret the SU6-relation as a consistency condition between the weak couplings characterizing the Wigner and Goldstone modes of chiral symmetry and demonstrate its importance for several effective chiral models of nuclear structure.