We report on the first determination of upper limits on the branching ratio (BR) of η decay to π0π0γ and to π0π0γ. Both decay modes are strictly forbidden by charge conjugation (C) invariance. Using the Crystal Ball multiphoton detector, we obtained BR(η→ π0 π0) < 5 × 10-4 at the 90% confidence level, in support of C invariance of isoscalar electromagnetic interactions of the light quarks. We have also measured BR(η→ π0π0γ) < 6 × 10-5 at the 90% confidence level, in support of C invariance of isovector electromagnetic interactions.
ASJC Scopus subject areas
- Physics and Astronomy(all)