γγ-PHYSICS AT KLOE/KLOE-2

Photon-photon interactions have been studied at the ϕ-factory DAΦNE with the detector KLOE operating the machine at $\sqrt{s} \simeq 1$ GeV, without tagging of the final leptons. The results about the γγ → η process and the evidence for γγ → π0π0 production at low π0π0 invariant mass are reviewed. The process γγ → π0 will be studied at KLOE-2 running the machine at ϕ-peak thanks to new lepton tagger detectors. In particular, the possibility to measure the two-photon width of π0 and the π0γ*γ transition form factor in the low (space-like) Q2 region is considered.