Branching Fraction Measurements of the Decays B -> EtaC K, where EtaC -> KKbarPi and EtaC -> 4K

Abstract

In this report, we present the observation of the exclusive decays B0 -> EtaC K0 and B+ -> EtaC K+, and the measurement of the related branching fractions. Using a sample of 22.7x10^6 Upsilon(4S) -> BBbar decays collected with the BABAR detector at the SLAC PEP-II asymmetric B Factory during 1999-2000, we have observed statistically significant signals in the EtaC -> KsK+Pi- and K+K-Pi0 channels and set upper limits in the EtaC -> K+K-K+K- channels. All the results presented are preliminary. We have measured BF(B+ -> EtaC K+) = (1.50 +/- 0.19 +/- 0.15 +/- 0.46)x10^{-3} BF(B0 -> Etac K0) = (1.06 +/- 0.28 +/- 0.11 +/- 0.33)x10^{-3} where the first error is statistical, the second systematic and the last due to the uncertainty on the world average EtaC -> KKbarPi branching fraction.