Evidence for Isospin Violation and Measurement of CP Asymmetries in B ?k? (892)?

Abstract

We report the first evidence for isospin violation in B?K?? and the first measurement of the difference of CP asymmetries between B+?K?+? and B0?K?0?. This analysis is based on the data sample containing 772�106BB pairs that was collected with the Belle detector at the KEKB energy-asymmetric e+e- collider. We find evidence for the isospin violation with a significance of 3.1?, ?0+=[+6.2�1.5(stat)�0.6(syst)�1.2(f+-/f00)]%, where the third uncertainty is due to the uncertainty on the fraction of B+B- to B0B0 production in (4S) decays. The measured value is consistent with predictions of the standard model. The result for the difference of CP asymmetries is ?ACP=[+2.4�2.8(stat)�0.5(syst)]%, consistent with zero. The measured branching fractions and CP asymmetries for charged and neutral B meson decays are the most precise to date. We also calculate the ratio of branching fractions of B0?K?0? to Bs0???. � 2017 American Physical Society.