Implications of recent B0-->D(*)0X0 measurements

The recent measurements of the color-suppressed modes B⁰-->D^(*)0π⁰ imply nonvanishing relative final-state interaction (FSI) phases among various Bbar-->Dπ decay amplitudes. Depending on whether or not FSIs are implemented in the topological quark-diagram amplitudes, two solutions for the parameters a₁ and a₂ are extracted from data using various form-factor models. It is found that \|a₂(Dπ)\|~0.35-0.60 and \|a₂(D^*π)\|~0.25-0.50 with a relative phase of order 60° between a₁ and a₂. If FSIs are not included in quark-diagram amplitudes from the outset, a^eff₂/a^eff₁ and a^eff₂ will become smaller. The large value of \|a₂(Dπ)\| compared to \|a^eff₂(Dπ)\| or naive expectation implies the importance of long-distance FSI contributions to color-suppressed internal W emission via final-state rescatterings of the color-allowed tree amplitude.