Two photon physics at BESIII

The anomalous magnetic momentum of the muon, aµ = (g−2), has been considered as one of the variables with which to test the completeness of the Standard Model. It has been precisely measured experimentally and calculated theoretically, but there is a 3 to 4 standard deviations between measurement and calculation. The dominant contribution to the uncertainty in the theoretical calculation comes from the hadronic part, including hadronic vacuum polarization and hadronic light-by-light scattering. The two-photon fusion process at electron-positron colliders can be used to measure the space-like transition form factors, which will served as an input or constraint to the calculation of the hadronic light-by-light contribution to aµ. Studies of the form factors using two-photon processes for π0, η and η′, as well as the cross-section of γγ* → π+π− are presented.