Evidence for B+ -> K0barK+ and B0 -> K0K0bar, and Measurement of the Branching Fraction and Search for Direct CP Violation in B+ -> K0pi+

Abstract

We present evidence for the b -> d penguin-dominated decays B+ -> K0barK+ and B0 -> K0K0bar with significances of 3.5 and 4.5 standard deviations, respectively. The results are based on a sample of 227 million Y(4S) -> BBbar decays collected with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC. We measure the branching fractions Br(B+ -> K0barK+) = (1.5 +- 0.5 +- 0.1) x 10^{-6} (< 2.4 x 10^{-6}) and Br(B0 -> K0K0bar) = (1.19^{+0.40}_{-0.35} +- 0.13) x 10^{-6}, where the uncertainties are statistical and systematic, respectively, and the upper limit on the branching fraction for K0barK+ is at the 90% confidence level. We also present improved measurements of the charge-averaged branching fraction Br(B+ -> K0pi+) = (26.0 +- 1.3 +- 1.0) x 10^{-6} and CP-violating charge asymmetry A_CP(K0pi+) = -0.09 +- 0.05 +- 0.01, where the uncertainties are statistical and systematic, respectively.

7 pages, 1 figure, 1 table, submitted to Physical Review Letters

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Cited by in corpus (8)

• Observation of B+ --> K0bar K+ and B0 --> K0 K0bar
• Final State Interaction In $B\to KK$ Decays
• Exploring B_{d,s}-> KK decays through flavour symmetries and QCD-factorisation
• Observation of B Decays to Two Kaons
• Bs-->K+K- and Bs-->K0 anti-K0 Decays within Supersymmetry
• Towards the European strategy for particle physics: the Briefing Book
• The rare decays B --> K(*) anti-K(*) and R-parity violating supersymmetry
• Connecting B_d and B_s decays through QCD factorisation and flavour symmetries