Observation of the Hadronic Transitions chi_b1,2 (2P) --> omega Upsilon(1S)

TL;DR

This paper reports the first observation of hadronic transitions among bottomonium states involving omega mesons, expanding understanding of bottomonium decay modes beyond dipion transitions.

Contribution

The study provides the first measurements of omega-mediated hadronic transitions in bottomonium, specifically chi_b1,2(2P) to omega Y(1S), with quantified branching ratios.

Findings

First observation of omega transitions in bottomonium.

Measured branching ratios for chi_b1(2P) and chi_b2(2P) decays.

Results are consistent with theoretical expectations.

Abstract

The CLEO Collaboration has made the first observations of hadronic transitions among bottomonium (b-bbar) states other than the dipion transitions among upsns states. In our study of Y(3S) decays, we find a significant signal for Y(3S) -> gamma omega Y(1S) that is consistent with radiative decays Y(3S) -> gamma chi_b1,2(2P), followed by chi_b1,2(2P) -> omega Y(1S). The branching ratios we obtain are B(chi_b1(2P) -> omega Y(1S)) = (1.63 +0.35-0.31 +0.16-0.15)% and B(chi_b2(2P) -> omega Y(1S)) = (1.10 +0.32-0.28 +0.11-0.10)%, in which the first error is statistical and the second is systematic.