Open Access Kent State (OAKS)

The dynamics of the η→3π⁰ decay have been studied with the Crystal Ball multiphoton spectrometer and the TAPS calorimeter. Bremsstrahlung photons produced by the 1.5-GeV electron beam of the Mainz microtron MAMI-C and tagged by the Glasgow photon spectrometer were used for η-meson production. The analysis of 3×10⁶ γp→ηp→3π⁰p→6γp events yields the value α=−0.032±0.003 for the η→3π⁰ slope parameter, which agrees with the majority of recent experimental results and has the smallest uncertainty. The π0π0invariant-mass spectrum was investigated for the occurrence of a cusplike structure in the vicinity of the π+π− threshold. The observed effect is small and does not affect our measured value for the slope parameter.