Evidence for B+â†'KÂ0K+ and B0â†'K0K 0, and measurement of the branching fraction and search for direct CP violation in B+â†'K0Ï€+

We present evidence for the bâ†d penguin-dominated decays B+â†KÂ0K+ and B0â†K0KÂ0 in 227A-106 I¥(4S)â†'BBÂdecays collected with the BABAR detector. We measure the branching fractions B(B+â†'KÂ0K+)= (1.5±0.5±0.1)A-10-6(<2.4A-10-6) and B(B0â†'K0KÂ0)=(1.19-0.35+0.40±0.13) A-10-6, where the uncertainties are statistical and systematic, respectively. We also present improved measurements of the charge-averaged branching fraction B(B+â†'K0I€+)=(26.0±1. 3±1.0)A-10-6 and CP-violating charge asymmetry ACP(K0I€+)=-0.09±0.05±0.01, where the uncertainties are statistical and systematic, respectively. © 2005 The American Physical Society.