On the possibility to measure the π 0→γγ decay width and the γ ∗ γ→π 0 transition form factor with the KLOE-2 experiment

A possibility of KLOE-2 experiment to measure the width \(\varGamma_{\pi^{0} \to\gamma\gamma}\) and the π0γγ∗ form factor F(Q2) at low invariant masses of the virtual photon in the space-like region is considered. This measurement is an important test of the strong interaction dynamics at low energies. The feasibility is estimated on the basis of a Monte-Carlo simulation. The expected accuracy for \(\varGamma_{\pi^{0} \to\gamma\gamma}\) is at a per cent level, which is better than the current experimental world average and theory. The form factor will be measured for the first time at Q2≤0.1 GeV2 in the space-like region. The impact of these measurements on the accuracy of the pion-exchange contribution to the hadronic light-by-light scattering part of the anomalous magnetic moment of the muon is also discussed.