Abstract
We report the first observation of the radiative decay using a data sample of pairs collected at the resonance with the Belle detector at the KEKB asymmetric-energy collider. We observe a signal of events with a significance of 5.4 standard deviations including systematic uncertainties. The measured branching fraction is , where the uncertainties are statistical and systematic, respectively. We also report the first measurements of time-dependent -violation parameters: and . Furthermore, we measure , , and find that the signal is concentrated in the mass region near threshold.
- Received 29 April 2011
DOI:https://doi.org/10.1103/PhysRevD.84.071101
© 2011 American Physical Society