UC Berkeley

We present a study of the decays B̄0→D(*)0K̄(*)0 using a sample of 226×106 Υ(4S)→BB̄ decays collected with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at SLAC. We report evidence for the decay of B0 and B̄0 mesons to the D*0KS0 final state with an average branching fraction B(B∼0→D*0K∼0) ≡(B(B̄0→D*0K̄0)+B(B0→D*0K0))/2=(3. 6±1.2±0.3)×10-5. Similarly, we measure B(B∼0→ D0K∼0)≡(B(B̄0→D0K̄0)+B(B0→D0K0))/2=(5.3±0. 7±0.3)×10-5 for the D0KS0 final state. We measure B(B̄0→D0K̄*0)=(4.0±0.7±0.3)×10-5 and set a 90% confidence level upper limit B(B̄0→D̄0K̄*0) <1.1×10-5. We determine the upper limit for the decay amplitude ratio |A(B̄0→D̄0K̄*0)/A(B̄0→D0K̄*0)| to be less than 0.4 at the 90% confidence level. © 2006 The American Physical Society.