The production of the sigma(500) meson in gamma gamma --> pi0 pi0 is studied. In particular, the KLOE data collected during the DAPHNE run at sqrt(s)= 1 GeV are appropriate to this purpose because of the strong reduction of Kaon backgrounds.
@article{arxiv.hep-ph/0602205,
title = {e+e- --> e+e- pi0 pi0 at Daphne},
author = {F. Nguyen and F. Piccinini and A. D. Polosa},
journal= {arXiv preprint arXiv:hep-ph/0602205},
year = {2009}
}