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

TL;DR

This paper uses Padé Approximants to analyze experimental data on the b3*b3 d7 c0^0 transition form factor at low energies, providing a model-independent extraction of its slope and curvature, and discussing implications for muon g-2.

Contribution

It introduces a model-independent method using Padé Approximants to analyze transition form factor data and extract low-energy parameters.

Findings

Extracted slope a_{\u03c0} and curvature b_{c0} of the form factor.

Provided a systematic low-energy description of the form factor.

Discussed the impact on the pion exchange contribution to muon g-2.

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.