Observation of ${B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}\ensuremath{\omega}{K}^{\ifmmode\pm\else\textpm\fi{}}$ Decay

Observation of $B^{\pm} \to ω K^{\pm}$ Decay

R.-S. Lu et al. (Belle Collaboration)

Phys. Rev. Lett. 89, 191801 – Published 16 October 2002

Abstract

We report the first observation of the charmless two-body mode $B^{\pm} \to ω K^{\pm}$ decay, and a new measurement of the branching fraction for the $B^{\pm} \to ω π^{\pm}$ decay. The measured branching fractions are $B (B^{\pm} \to ω K^{\pm}) = ({9.2}_{- 2.3}^{+ 2.6} \pm 1.0) \times 10^{- 6}$ and $B (B^{\pm} \to ω π^{\pm}) = ({4.2}_{- 1.8}^{+ 2.0} \pm 0.5) \times 10^{- 6}$ . We also measure the partial rate asymmetry of $B^{\pm} \to ω K^{\pm}$ decays and obtain $A_{C P} = - 0.21 \pm 0.28 \pm 0.03$ . The results are based on a data sample of $29.4 {f b}^{- 1}$ collected on the $Υ (4 S)$ resonance by the Belle detector at the KEKB $e^{+} e^{-}$ collider.