Investigation of the $e^+e^- \to ωπ^0 \to π^0 π^0 γ$ reaction in the energy domain near the $ϕ$-meson

Abstract

The $e^+e^- \to ωπ^0 \to π^0 π^0 γ$ process was investigated in the SND experiment at the VEPP-2M collider. A narrow energy interval near the $ϕ$-meson was scanned. The observed cross-section reveals, at the level of three standard deviation, the interference effect caused by $ϕ\to π^0π^0γ$ decay. The cross-section parameters, as well as the real and imaginary parts of the $ϕ$-meson related amplitude, were measured.

34 pages, 7 figures, LaTeX, uses FEYNMAN package. Erroneously reported C_{12} coefficient corrected (an error discovered in hep-ph/0603241). in the published version Nucl. Phys. B569(2000), 158 this coefficient is reported incorrectly