THE PI-SIGMA-AXIAL EXCHANGE CURRENT

Tle axial exchange current operator that arises from the coupling of t he axial field to the pion and effective scalar field in nuclei is con structed using the modified sigma-model. The corresponding effective o ne-body operator is then constructed using short range correlation fun ctions determined from realistic nucleon-nucleon interaction models. I t is shown that the ''pisigma''-axial exchange current can contribute about 5% to the quenching of the nucleon axial current coupling consta nt g(A)GT in heavy nuclei.