PNNL

Abstract

We report measurements of the branching fractions and CPasymmetries for B±h± (h=K_or p) and the observation of the decay B°K° from the final data sample of 772 × 106BB pairs collected with the Belle detector at the KEKB asymmetric-energy e?e¯ collider. The measured branching fractions are ?(B±?nK±) – (2.12 ± 0.23 ± 0.11) x 10-6 and ? (B±?nK±) = (2.12 ± 0.23 ± 0.11) × 10¯6, ?(B±?np±) = (4.07 ± 0.26 ± 0.21) × 10¯6and ?(B°? nK°) = (1.27+0.33-0.29 ± 0.08) × 10¯6, where the last decay is observed for the first time with a significance of 5.4 standard deviations (s). We also find evidence for CP violation in the charged B modes, ACP(B±?nK±) = -0.38 ± 0.11 ± 0.01 and ACP(B±?nK±) = -0.19 ± 0.06 ± 0.01 with significances of 3.8s and 3.0s, respectively. For all measurements, the first and second uncertainties are statistical and systematic, respectively.