UC Berkeley

We present a preliminary study of B- → D 0 (CP)π- and B- → D 0 (CP)K- decays, with the D 0 (CP)reconstructed in the CP-odd eigenstates Ksπ0, Ks, in the CP-even eigenstates K+K-, π+π-, and in the (non-CP) flavor eigenstate K ± π ± . Using a sample of about 382 million γ(4S) decays into BB pairs, collected with the BABAR detector operating at the PEP-II asymmetric-energy B Factory at SLAC, we measure the ratios of the branching fractions B(B- → D 0 CP±K-) + B(B+ → D 0 CP±K+) [B(B- → D 0 K-) + B(B+ → D 0 K+)]/2 and the direct CP asymmetry ACP± Ξ B(B-→D 0 CP±K-) - B(B+→D 0 CP±K+) B(B-→D 0 CP±K-) + B(B+→D 0 CP±K+) . The results are: RCP- = 0.81 ± 0.10(stat) ± 0.05(syst) RCP+ = 1.07 ± 0.10(stat) ± 0.04(syst) ACP- = -0.19 ± 0.12(stat) ± 0.02(syst) ACP+ = 0.35 ± 0.09(stat) ± 0.05(syst).