Shape of the $f_0(980)$ in $\gamma \gamma \to {\pi }^{+}{\pi }^{-}$

N. N. Achasov, G. N. Shestakov

The Belle Collaboration results on the observation of the $f_0(980)$ resonance in the reaction $\gamma \gamma \to {\pi }^{+}{\pi }^{-}$ are analyzed. It is argued that they point to the presence of mechanism…