Non-factorizable long distance contributions in color suppressed decays of B mesons

Abstract

$\bar B \to Dπ$, $D^*π$, $J/ψ\bar K$ and $J/ψπ$ decays are studied. Their amplitude is given by a sum of factorized and non-factorizable ones. The latter which is estimated by using a hard pion approximation is rather small in color favored $\bar B \to Dπ$ and $D^*π$ decays but still can efficiently interfere with the main amplitude given by the factorization. In the color suppressed $\bar B \to J/ψ\bar K$ and $J/ψπ$ decays, the non-factorizable contribution is very important. The sum of the factorized and non-factorizable amplitudes can reproduce well the existing experimental data on the branching ratios for the color favored $\bar B \to Dπ$ and $D^*π$ and the color suppressed $\bar B \to J/ψ\bar K$ and $J/ψπ$ decays by taking reasonable values of unknown parameters involved.