We present new measurements of branching fractions for the color-favored decays B+ → D0π- and B̄0 → D+π-. Using 9.67×106 BB̄ pairs collected with the CLEO detector, we obtain the branching fractions Β(B- → D0π - = (49.7±1.2±2.9±2.2)×104 and Β(B̄0 → D+π-) = (26.8±1.2±2.4±1.2)×10-4. The first error is statistical, the second is systematic, and the third is due to the experimental uncertainty on the production ratio of charged and neutral B mesons in Y(4S) decays. These results, together with the current world average for the color-suppressed branching fraction Β(B̄+ → D 0π0), are used to determine the cosine of the strong phase difference δI between the I = 1/2 and I=3/2 isospin amplitudes. We find cos δI = 0.863 -0.023-0.035-0.030+0.024+0.036+0.038, and obtain a 90% confidence interval of 16.5° < δI < 38.1°. This nonzero value of δI suggests the presence of final state interactions in the D π system.
ASJC Scopus subject areas
- Nuclear and High Energy Physics