Abstract
We report on the first determination of upper limits on the branching ratio () of decay to and to . Both decay modes are strictly forbidden by charge conjugation () invariance. Using the Crystal Ball multiphoton detector, we obtained at the 90% confidence level, in support of invariance of isoscalar electromagnetic interactions of the light quarks. We have also measured at the 90% confidence level, in support of invariance of isovector electromagnetic interactions.
- Received 10 September 2004
DOI:https://doi.org/10.1103/PhysRevLett.94.041601
©2005 American Physical Society