Measurement of CP Asymmetry in B0 --> K+K-K0(S) Decays

Abstract

We present preliminary measurements of the CP asymmetry parameters and CP content in B0-->K+K-Ks decays, with phiKs events excluded. In a sample of 227M BB pairs collected by the BABAR detector at the PEPII B-Factory at SLAC, we find the CP parameters to be S = -0.42 +/- 0.17 +/- 0.04 and C = 0.10 +/- 0.14 +/- 0.06, where the first error is statistical and the second is systematic. Extracting the fraction of CP -even final states from angular moments f(CP-even) = 0.89 +/- 0.08 +/- 0.06, and setting C=0, we determine sin(2beta) = 0.55 +/- 0.22 +/- 0.04 +/- 0.11, where the last error is due to uncertainty on the CP content.