Observation of the Hadronic Transitions Chi_{b 1,2}(2P) -> omega Upsilon(1S)

TL;DR

This paper reports the first observation of a hadronic transition between bottomonium states involving omega meson emission, expanding understanding of bottomonium decay modes.

Contribution

It presents the first experimental evidence of chi_{b 1,2}(2P) -> omega Upsilon(1S) transitions, a novel decay process in bottomonium physics.

Findings

Measured branching ratios for chi_{b1} and chi_{b2} decays to omega Upsilon(1S).

Confirmed the presence of the hadronic transition among bottomonium states.

Provided experimental data supporting theoretical models of bottomonium decay mechanisms.

Abstract

The CLEO Collaboration has observed the first hadronic transition among bottomonium (b bbar) states other than the dipion transitions among vector states, Upsilon(nS) -> pi pi Upsilon(mS). In our study of Upsilon(3S) decays, we find a significant signal for Upsilon(3S) -> gamma omega Upsilon(1S) that is consistent with radiative decays Upsilon(3S) -> gamma chi_{b 1,2}(2P), followed by chi_{b 1,2} -> omega Upsilon(1S). The branching ratios we obtain are Br(chi_{b1} -> omega Upsilon(1S) = 1.63 (+0.35 -0.31) (+0.16 -0.15) % and Br(chi_{b2} -> omega Upsilon(1S) = 1.10 (+0.32 -0.28) (+0.11 - 0.10)%, in which the first error is statistical and the second is systematic.