Regge asymptotics and color suppressed heavy meson decays

We discuss a possible generation of color suppressed B-decays amplitudes through a soft final state interaction. As a typical example, we consider in detail the decay $\bar{B}^{0} \rightarrow D^{0} \pi^{0}$ (and also $\bar{B}^{0} \rightarrow 2 \pi^{0}$). We show that in the approximation of the two particle unitarity and at zero order in $\alpha_{s}$ this process can be related to the weak decay $\bar{B}^{0} \rightarrow D^{+} \pi^{-}$ followed by the strong charge exchange scattering in the Regge kinematics. We estimate the amplitude of this process using the light cone QCD sum rule technique and find that it is supppressed as a power of $1/m_{B}$ in comparison to the amplitude generated by the effective non-leptonic Hamiltonian, but remains important for the physical value of $m_{B}$.