Search for the Rare Decays B0 ->Ds(*)+ a0(2)-

We have searched for the decays B 0 → D + s a − 0 , B 0 → D ∗ + s a − 0 , B 0 → D + s a − 2 and B 0 → D ∗ + s a − 2 in a sample of about 230 million Υ (4 S ) → BB decays collected with the B A B AR detector at the PEP-II asymmetric-energy B Factory at SLAC. We find no evidence for these decays and set upper limits at 90% C.L. on the branching fractions: B ( B 0 → D + s a − 0 ) < 1 . 9 × 10 − 5 , B ( B 0 → D ∗ + s a − 0 ) < 3 . 6 × 10 − 5 , B ( B 0 → D + s a − 2 ) < 1 . 9 × 10 − 4 , and B ( B 0 → D ∗ + s a − 2 ) < 2 . 0 × 10 − 4 .