Abstract
Using a sample of events collected with the BESIII detector at the BEPCII collider, we study the decays of and . The branching fraction of is determined to be , which significantly improves on previous measurements. No clear signal is observed for the process, and the upper limit at the 95% confidence level for its branching fraction is determined to be , which improves on the previous searches by 2 orders in magnitude and reaches the order of the Einstein-Podolsky-Rosen expectation.
- Received 16 October 2017
DOI:https://doi.org/10.1103/PhysRevD.96.112001
© 2017 American Physical Society