%0 Journal Article %A Briere, Roy %A A. Ferguson, Thomas %A Tatishvili, G. %A Vogel, Helmut %A Watkins, M. E. %A Collaboration, CLEO %D 2008 %T Observation of Υ(2S)→ηΥ(1S) and Search for Related Transitions %U https://kilthub.cmu.edu/articles/journal_contribution/Observation_of_2S__1S_and_Search_for_Related_Transitions/6507701 %R 10.1184/R1/6507701.v1 %2 https://kilthub.cmu.edu/ndownloader/files/11971796 %K Physics %X

We report the first observation of Υ(2S)→ηΥ(1S), with a branching fraction B=(2.1-0.6+0.7(stat)±0.3(syst))×10-4 and a statistical significance 5.3σ. Data were acquired with the CLEO III detector at the CESR e+e- symmetric collider. This is the first process observed involving a b-quark spin flip. For related transitions, 90% confidence limits in units of 10-4 are B(Υ(2S)→π0Υ(1S))0Υ(1S))0Υ(2S))<5.1.

%I Carnegie Mellon University