A phenomenological study of γγ → π0π0 at low energies

The neutral-pion mode of the two-photon process (γγ → ππ) is herein, the subject of a phenomenological study. The experimental data, to which the theoretical descriptions of the total cross-section will be fitted, are provided by the Crystal Ball Collaboration. As a result, new estimates for Γ(f0 → γ γ) and Γ(f2→gammagamma'') are predicted and used thereafter to evaluate the validity of the cross-sections models that yielded them. Fixed-t dispersion relations, Breit-Wigner formalism, and Vector-Meson Dominance are the main theoretical means of this study which is characterised by the emergence of the crossed channel (γπ0 →γπ0) contribution as a possible explanation to account for the presence of the observed experimental low-energy background in the direct channel. (author)