Measurement of the branching fraction and CP asymmetry for B → D ¯ 0π decays

Abstract

We measure the branching fractions and CP asymmetries for the decays B0→D¯0π0 and B+→D¯0π+, using a data sample of 772×106 BB¯ pairs collected at the (4S) resonance with the Belle detector at the KEKB e+e- collider. The branching fractions obtained and direct CP asymmetries are B(B0→D¯0π0)=[2.70±0.06(stat)±0.10(syst)]×10-4, B(B+→D¯0π+)=[4.53±0.02(stat)±0.15(syst)]×10-3, ACP(B0→D¯0π0)=[+0.42±2.05(stat)±1.22(syst)]%, and ACP(B+→D¯0π+)=[+0.19±0.36(stat)±0.57(syst)]%. The measurements of B are the most precise to date and are in good agreement with previous results, as is the measurement of ACP(B+→D¯0π+). The measurement of ACP for B0→D¯0π0 is the first for this mode, and the value is consistent with Standard Model expectations.