Using the Crystal Ball detector at the e+e- storage ring DORIS-II, we have searched for the hadronic transitions Υ(2 S)→ηΥ(1 S) and Υ(2 S)→π0Υ(1 S) in exclusive decays where the Υ(1 S) decays into an e+e- or a μ+μ- pair and the η and π0 are detected by their decay modes η→γγ, η→γγ and π0→γγ. From the number of observed events we derive, after consideration of possible background sources, upper limits on the branching ratios B(Υ(2 S)→ηΥ(1 S))<0.7% and B(Υ(2S)→π0Υ(1 S))<0.8% at the 90% confidence level.
|Original language||English (US)|
|Number of pages||6|
|Journal||Zeitschrift für Physik C Particles and Fields|
|State||Published - Sep 1987|
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)