Measurement of the Branching Ratios for J/ ψ → γπ 0 , γη '→3 γ on the BES

Decays of the J/ψ resonance into the three-photon final state are investigated. Branching ratios for the decays of J/ψ→γπ0 and J/ψ→γη' are determined to be Br(J/ψ→γπ0)=(4.6±1.1)×10-5 and Br(J/ψ→γη')=(4.12±0.82)—10-3. The ratio of the two decay widths, Γ(J/ψ→γη')/Γ(J/ψ→γη),is 4.79±0.85. This value agrees weM with the predictions of the two theoretical models.