$σ^{tot}_{ee γγ}$ at $e^+e^-$ colliders}

Abstract

In this talk I briefly summarize different models for $σ^{tot}_{2 γ}$ ($e^+e^- \to γγ\to$ hadrons) and contrast model predictions with the data. I will then discuss the capability of the future $e^+e^-$ and $γγ$ colliders to distinguish between various models and end with an outlook for future work.