ON THE HIGHER-LOOP CONTRIBUTIONS TO THE AXIAL ANOMALY

The problem of the higher-loop corrections to the axial anomaly is ree xamined by a new method. We demonstrate that these contributions depen d on the order in which different operations are performed. If the div ergence of the axial current is calculated first, and then averaged ov er the photon field in the presence of an external photon source, a no nzero contribution is obtained. However the perturbative Feynman diagr am method has an uncertainty. Depending on the order of the operation, one can get the above mentioned result or zero.