Two-loop contribution to the pion transition form factor vs. experimental data

We present predictions for the pion-photon transition form factor, which is derived with the help of light-cone sum rules and including the main part of the NNLO radiative corrections. We show that, when the Bakulev-Mikhailov-Stefanis (BMS) pion distribution amplitude is used, the obtained predictions agree well with the CELLO and the CLEO data. We found that no model distribution amplitude can reproduce the observed Q2 growth of the new BaBar data, though the BMS model complies with several BaBar data points.