Axial anomaly and vector meson dominance model

A connection between the axial anomaly and the vector meson dominance model is revealed for the processes of pseudoscalar meson-photon transitions. The analytical continuation of the anomaly sum rules, which are exact QCD relations following follow from the dispersive representation of the axial anomaly, to the time-like region is performed. Using these sum rules, the transition form factors of $\pi^0$, $\eta$, and $\eta'$ mesons in this region are calculated. A good agreement with the available experimental data is found.