Search for B_{s}^{0}->hh Decays at the ${\rm Y}(5S)$ Resonance

Abstract

We have searched for B_{s}^{0}->hh decays, where h stands for a charged or neutral kaon, or a charged pion. These results are based on a 23.6 fb^{-1} data sample collected with the Belle detector on the Υ(5S) resonance at the KEKB asymmetric-energy e^{+}e^{-} collider, containing 1.25x10^6 B_{s}^{(*)}\bar{B}_{s}^{(*)} events. We observe the decay B_{s}^{0}->K^{+}K^{-} and measure its branching fraction, \mathcal{B}(B_{s}^{0}->K^{+}K^{-}) = [3.8_{-0.9}^{+1.0}(\mathrm{stat})\pm 0.5(\mathrm{syst})\pm 0.5(f_s)] \times 10^{-5}. The first error is statistical, the second is systematic, and the third error is due to the uncertainty in the B^0_s production fraction in $e^{+}{e}^{-}\to b\bar{b}$ events. No significant signals are seen in other decay modes, and we set upper limits at 90% confidence level: \mathcal{B}(B_{s}^{0}->K^-π^{+})< 2.6 \times 10^{-5}, \mathcal{B}(B_{s}^{0}->π^{+}π^{-})< 1.2 \times 10^{-5} and \mathcal{B}(B_{s}^{0}->K^0\bar{K}^0) < 6.6\times 10^{-5}.

6 pages, 2 figure, two tables

References in corpus (4)

• Measurement of $\boldmath {B_s^0}$ mixing parameters from the flavor-tagged decay
• Observation of anomalous Upsilon(1S)pi+pi- and Upsilon(2S)pi+pi- production near the Upsilon(5S) resonance
• Measurement of the Decay B_s^0 -> D_s^- pi^+ and Evidence for B_s^0 -> D_s^{+/-} K^{-/+} in e+e- Annihilation at sqrt(s)~10.87 GeV
• Exploring B_{d,s}-> KK decays through flavour symmetries and QCD-factorisation