Improved measurements of branching fractions and CP partial rate asymmetries for B ->omega K and B ->omega pi

We report improved measurements of B to pseudoscalar-vector decays containing an omega meson in the final state. Our results are obtained from a data sample that contains 388x10(6) B (B) over bar pairs accumulated at the Upsilon(4S) resonance, with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We measure the following branching fractions: B(B+->omega K+)=[8.1 +/- 0.6(stat.)+/- 0.6(syst.)]x10(-6), B(B+->omega pi(+))=[6.9 +/- 0.6(stat.)+/- 0.5(syst.)]x10(-6), and B(B-0 ->omega K-0)=[4.4(-0.7)(+0.8)(stat.)+/- 0.4(syst.)]x 10(-6). The partial width ratio (Gamma(B+->omega K+))/(Gamma(B0 ->omega K0))=1.7 +/- 0.3(stat.)+/- 0.1(sys.). We also set the 90% confidence level upper limit B(B-0 ->omega pi(0)) omega K+, and A(CP)=-0.02 +/- 0.09(stat.)+/- 0.01(syst.) for B+->omega pi(+).