The fate of the axial anomaly in a finite field theory

Abstract

The conservation of the vector current and the axial anomaly responsible for the ${\pi }_0\to \gamma \gamma$ decay amplitude are obtained in leading order within the Taylor-Lagrange formulation of fields considered as operator-valued distributions. As for gauge theories, where this formulation eliminates all divergences and preserves gauge-symmetry, it is shown that the different contributions can be evaluated directly in $4$-dimensional space-time, with no restrictions whatsoever on the four-momentum of the internal loop, and without the need to introduce any additional non physical degrees of freedom like Pauli-Villars fields. We comment on the similar contributions responsible for the decay of the Higgs boson into two photons.

Comments: 15 pages, one figure