Measurements of Branching Fractions and CP-Violating Asymmetries in B-Meson Decays to the Charmless Two-Body States K{sup 0}pi+, K-bar{sup 0}K{sup +}, and K{sup 0}K-bar{sup 0}

Abstract

The authors present preliminary measurements of the branching fraction and the CP-violating charge asymmetry in the B{sup +} --> K{sup 0}{pi}{sup +} decay, and a preliminary measurement of the branching fraction of the B{sup 0} --> K{sup 0}{bar K}{sup 0} decay. No evidence of direct CP violation in the B{sup +} --> K{sup 0}{pi}{sup +} mode is observed. The B{sup 0} --> K{sup 0}{bar K}{sup 0} measurement constitutes the first observation of this decay channel: the probability of obtaining the result assuming the null-signal hypothesis is 3.4 x 10{sup -6}. The authors have also searched for the B{sup +} --> {bar K}{sup 0}K{sup +} decay and set an upper limit on its branching fraction at 2.35 x 10{sup -6} at the 90% C.L. The branching-fraction measurements reported here are consistent with previous measurements of the same quantities, but are extracted from a data sample larger by a factor of 2.6.