Is the scalar meson seen in CELLO data on $\gamma \gamma \to {\pi }^{+}{\pi }^{-}$ ?

Abstract

We analyze the CELLO angular distributions $\gamma \gamma \to {\pi }^{+}{\pi }^{-}$ with the unitary model \cite{KS-86} for helicity 2 amplitude. In contrast to previous analysis \cite{CELLO} we do not see any QED damping. The obtained S--wave does not contradict to low--energy theorem and demonstrates more clealy the resonance--like behaviour near 1.3 Gev.

LaTeX, 9 pages, 4 figures (not included, hard copy available upon request), ISU-IAP.Th93-04,\ Irkutsk