Measurements of B Decays to Two Kaons

We report measurements of B meson decays to two kaons using 250/fb of data collected with the Belle detector at the KEKB asymmetric energy e+ e- collider. We find evidence of signals in B+ -> K0(bar) K+ and B0 -> K0 K0(bar) with significances of 3.0 sigma and 3.5 sigma, respectively. The corresponding branching fractions are measured to be BF(B+ -> K0(bar) K+) = (1.0+-0.4+-0.1) x 10^-6 and Br(B0 -> K0 K0(bar)) = 0.8+-0.3+-0.1) x 10^-6. These decay modes are examples of hadronic b -> d transitions. No signal is observed in the decay B0 -> K+ K- and we set an upper limit of 3.7 x 10^-7 at 90% confidence level.