Measurement of the branching fractions and CP-asymmetry of B^- -> D^0_(CP) K^- decays with the BaBar detector

Abstract

We present a study of B−→DCP0K− decays, where DCP0 is reconstructed in CP-even channels, based on a sample of 88.8×106 Υ(4S)→BB¯ decays collected with the BABAR detector at the PEP-II e+e− storage ring. We measure the ratio of Cabibbo-suppressed to Cabibbo-favored branching fractions B(B−→DCP0K−)/B(B−→DCP0π−)=[8.8±1.6(stat)±0.5(syst)]×10−2 and the CP asymmetry ACP=0.07±0.17(stat)±0.06(syst). We also measure B(B−→D0K−)/B(B−→D0π−)=[8.31±0.35(stat)±0.20(syst)]×10−2 using a sample of 61.0×106 BB¯ pairs.