Search for the CP-violating decays γ(4S) → B0 B-bar 0 → J/ψK0S + J/ψ(ηc)K0S

We report the first search for CP violating decays of the γ(4S) using a data sample that contains 535 million γ(4S) mesons with the Belle detector at the KEKB asymmetric-energy e+e- collider. A partial reconstruction technique is employed to enhance the signal sensitivity. No significant signals were observed. We obtain an upper limit of 4 x 10-7 at the 90% confidence level for the branching fractions of the CP violating modes, γ(4S) → B0 B-bar 0 → J/ψKS0 + J/ψ (ηc)K0S. Extrapolating the result, we find that an observation with 5a significance is expected with a 30 ab-1 data sample, which is within the reach of a future super B factory