\gamma*\gamma \rightarrow \pi^0 transition form factor at low-energies from a model-independent approach

Abstract

The recent measured \gamma*\gamma \rightarrow \pi^0 transition form factor in the space-like region by the Belle Collaboration together with the previous published results by CLEO, CELLO and BABAR collaborations are analyzed using the mathematical theory of Pad\'e Approximants which provides a good and systematic description of the low energy region exemplified here with the extraction of the slope a_{\pi} and curvature b_{\pi} of the form factor in a model-independent way. The impact of them on the pion exchange contribution to the hadronic light-by-light scattering part of the anomalous magnetic moment a_{\mu} is also discussed.