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We explore the BaBar puzzle within the Regge approach. After reviewing thechiral quark models in applications to PDF and PDA of the pion, we argue thatvariants of these models, fulfilling the chiral anomaly, may in fact violatethe second Terazawa-West unitarity bound, which is based on unverifiedassumptions for the real part of the amplitude. Consequently, the transitionform factor need not vanish at large values of the photon virtuality. Then weshow that the experimental data may be properly explained with incompletevector-meson dominance in a simple model with one state, as well as in moresophisticated radial Regge models including infinitely many states. We alsoconsider the experimental constraint from the rare Z -> pi0 gamma decay, whichis comfortably satisfied in our approach. Finally, we point out that the photonmomentum asymmetry parameter may noticeably influence the precision fits to thedata.

Pion transition form factor in the Regge approach