Observation of (B)over-bar(0)-> D-0 pi(0) and (B)over-bar(0)-> D*(0)pi(0)

Abstract

We have studied the color-suppressed hadronic decays of neutral B mesons into the final states D-(*()0)pi(0). Using 9.67 x 10(6) B (B) over bar pairs collected with the CLEO detector, we observe the decays (B) over bar (0) --> D(0)pi(0) and (B) over bar (0) --> D*(0)pi(0) with the branching fraction B((B) over bar (0) --> D(0)pi(0)) = (2.74(-0.32)(+0.36) +/- 0.55) x 10(-4) and B((B) over bar (0) --> D*0pi0') = (2.20(-0.52)(+0.59) +/- 0.79) x 10(-4). The first error is statistical and the second systematic. The statistical significance of the D(0)pi(0) signal is 12.1sigma (5.9sigma for D*(0)pi(0)). Utilizing the (B) over bar (0) --> D-(*()0)pi(0) branching fractions we determine the strong phases delta(I,D(*)) between isospin 1/2 and 3/2 amplitudes in the Dpi and D*pi final states to be cosdelta(I,D) = 0.89 +/- 0.08 and cosdelta(I,D*) = 0.89 +/- 0.08, respectively.