Observation of B+- -> omega K+- Decay

TL;DR

This paper reports the first observation of the charmless decay mode B± to omega K± and measures its branching fraction, along with a new measurement for B± to omega pi±, using data from the Belle detector at KEKB.

Contribution

The study provides the first observation of B± to omega K± decay and new measurements of its branching fraction, enhancing understanding of charmless B meson decays.

Findings

First observation of B± to omega K± decay.

Measured branching fractions: (9.2+2.6-2.3±1.0)×10⁻⁶ for B± to omega K±.

Measured branching fraction: (4.2+2.0-1.8±0.5)×10⁻⁶ for B± to omega pi±.

Abstract

We report the first observation of the charmless two-body mode $B^{\pm} \to \omega K^{\pm}$ decay, and a new measurement of the branching fraction for the $B^{\pm} \to \omega \pi^{\pm}$ decay. The measured branching fractions are ${\cal B} (B^{\pm} \to \omega K^{\pm}) = (9.2{}^{+2.6}_{-2.3}\pm 1.0) \times 10^{-6}$ and ${\cal B} (B^{\pm} \to \omega \pi^{\pm}) = (4.2{}^{+2.0}_{-1.8}\pm 0.5) \times 10^{-6}$. %and we set 90% confidence level upper limits of %${\cal B} (B^- \to \omega \pi^-) < 8.1\times 10^{-6}$. We also measure the partial rate asymmetry of $B^{\pm}\to\omega K^{\pm}$ decays and obtain ${\cal A}_{CP} = -0.21 \pm 0.28 \pm 0.03$. The results are based on a data sample of 29.4 fb$^{-1}$ collected on the $\Upsilon(4S)$ resonance by the Belle detector at the KEKB $e^{+} e^{-}$ collider.