Emphasizing the different trends of the existing data for the $\gamma^*\gamma \to \pi^0$ transition form factor

Abstract

The new data on the $\gamma^*\gamma \to \pi^0$ transition form factor of the Belle Collaboration are analyzed in comparison with those of BaBar (including the older data of CELLO and CLEO) using an approach based on light-cone sum rules. Performing a 2-, and a 3-parametric fit to these data, we found that the Belle and the BaBar data have no overlap at the $1\sigma$ level. While the Belle data agree with our predictions, the Babar data are in conflict with them.