Abstract / Description of output
The dynamics of the eta -> 3 pi(0) 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 eta-meson production. The analysis of 3x10(6) gamma p ->eta p -> 3 pi(0)p -> 6 gamma p events yields the value alpha=-0.032 +/- 0.003 for the eta -> 3 pi(0) slope parameter, which agrees with the majority of recent experimental results and has the smallest uncertainty. The pi(0)pi(0) invariant-mass spectrum was investigated for the occurrence of a cusplike structure in the vicinity of the pi(+)pi(-) threshold. The observed effect is small and does not affect our measured value for the slope parameter.