Abstract
Using a data sample of events collected at with the BESIII detector at the Beijing Electron-Positron Collider II, we search for the rare decay via . No signal events are observed and the upper limit on the branching fraction is set to be at the 90% confidence level, which is still about one order of magnitude higher than the Standard Model prediction.
- Received 6 February 2019
DOI:https://doi.org/10.1103/PhysRevD.99.052010
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
Published by the American Physical Society