Pion and Kaon Pair Production in Photon-Photon Collisions

This is the authors' abstract. We don't add key points for this paper.

We report measurements of the two-photon processes e⁺e^-→e⁺e^-π⁺π^- and e⁺e^-→e⁺e^-K⁺K^-, at an e⁺e^- center-of-mass energy of 29 GeV. In the π⁺π^- data a high-statistics analysis of the $f(1270)$ results in a γγ width Γ(γγ→f)=3.2±0.4 keV. The π⁺π^- continuum below the f mass is well described by a QED Born approximation, whereas above the f mass it is consistent with a QCD-model calculation if a large contribution from the f is assumed. For the K⁺K^- data we find agreement of the high-mass continuum with the QCD prediction; limits on f^'(1520) and θ(1720) formation are presented.