Determining the Factorization Parameter and Strong Phase Differences in B→D^(*)π Decays

Abstract：

The first observation of the color suppressed decay mode B0d→D^(*)0π⁰ by the Belle and CLEO Collaborations makes a quantitative analysis of the isospin relations for the amplitudes of B→D^(*)π possible. The strong (isospin) phase difference in B→Dπ transitions is found to be about 29° by use of the Belle data or 26° by use of the CLEO data, implying that final state interactions might not be negligible. Applying the factorization approximation to I=3/2 and I=1/2 isospin amplitudes of B→Dπ decays, we obtain the ratio of the effective Wilson coefficients a eff 1and a eff 2∶ a eff 2/ a eff 1≈0.27. A similar analysis shows that the magnitude of final state interactions in B→D^*π might be comparable with that in B→Dπ, and the factorization hypothesis works consistently in both of them.