Tests for the asymptotic behaviour of the γ∗→γπ0 form factor

The γ∗→ωπ0 transition measured at different photon virtualities already provides us with a clean test for the behaviour of the π0γ∗γ off-shell axial anomaly at large time-like squared momenta. It also allows reliable predictions for the branching ratio of heavy quarkonium decays into ωπ0.