Abstrakt
We measure the branching fractions and CP asymmetries for the decays B-0 -> (D) over bar (0)pi(0) and B+ -> (D) over bar (0)pi(+), using a data sample of 772 x 10(6) B (B) over bar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB e(+)e(-) collider. The branching fractions obtained and direct CP asymmetries are B(B-0 -> (D) over bar (0)pi(0)) = [2.70 +/- 0.06(stat) +/- 0.10(syst)] x 10(-4), B(B+ -> (D) over bar (0)pi+) = [4.53 +/- 0.02(stat) +/- 0.15(syst)] x 10(-3), A(CP)(B-0 -> (D) over bar (0)pi(0)) = [+/- 0.42 +/- 2.05(stat) +/- 1.22(syst)]%, and A(CP)((D) over bar (0)pi(+)) = [+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 A(CP)((D) over bar (0)pi(+)). The measurement of A(CP) for B-0 -> (D) over bar (0)pi(0) is the first for this mode, and the value is consistent with Standard Model expectations.