First observation of exclusive $\\Upsilon(1S)$ and $\\Upsilon(2S)$ decays into light hadrons
Journal
Physical Review
Journal Volume
D86
Pages
031102
Date Issued
2012-05
Author(s)
Abstract
Using samples of 102×106 Υ(1S) and 158×106 Υ(2S) events collected with the Belle detector, we study exclusive hadronic decays of these two bottomonium resonances to the three-body final states Ï•K +K -, ωπ +π - and K *0(892)K -π +, and to the two-body Vector-Tensor states (Ï•f2′(1525), ωf 2(1270), ρa 2(1320) and K *0(892)K̄2*0(1430)) and Axial-vector-Pseudoscalar (K 1(1270) +K -, K 1(1400) +K - and b 1(1235) +π -) states. Signals are observed for the first time in the Υ(1S)→Ï•K +K -, ωπ +π -, K *0K -π +, K *0K2*0 and Υ(2S)→Ï•K +K -, K *0K -π + decay modes. Branching fractions are determined for all the processes, while 90% confidence level upper limits are established on the branching fractions for the modes with a statistical significance less than 3σ. The ratios of the branching fractions of Υ(2S) and Υ(1S) decays into the same final state are used to test a perturbative QCD prediction for OZI-suppressed bottomonium decays. © 2012 American Physical Society.
Type
journal article