We report the first determination of the upper limit for the branching ratio of the CP forbidden decay η → 4π0. No events were observed in a sample of 3.0 × 107 η decays. The experiment was performed with the Crystal Ball multiphoton spectrometer installed in a separated p- beam at the AGS (Alternating Gradient Synchrotron). At the 90% confidence limit, B(η → 4π0) ≤ 6.9 × 10-7.
ASJC Scopus subject areas
- Physics and Astronomy(all)