Non-factorizable contributions to B{sub d}{sup 0} {yields} D{sub s}{sup (*)}D{sub s}{sup (*)} from chiral loops and tree level 1/Nc terms

We point out that the amplitudes for the decays B-bar{sup 0} {yields} D{sub s}{sup +}D{sub s}{sup -} and B-bar{sub s}{sup 0} {yields} D{sup +}D{sup -} have no factorizable contributions. If one or two of the D-mesons in the final state are vectors (i.e D* 's) there are relatively small factorizable contributions through the annihilation mechanism. The dominant contributions to the decay amplitudes arise from chiral loop contributions and 1/Nc suppressed tree level. We predict that the branching ratios for the processes B-bar{sub d}{sup 0} {yields} D{sub s}{sup +}D{sub s}{sup -}, B-bar{sub d}{sup 0} {yields} D{sub s}{sup +}*D{sub s}{sup -} and B-bar{sub d}{sup 0} {yields} D{sub s}{sup +}D{sub s}{sup -}* are all of order (2 - 3) x 10-4, while B-bar{sub s}{sup 0} {yields} D{sub d}{sup +}D{sub d}{sup -}, B-bar{sub s}{sup 0} {yields} D{sub d}{sup +}*D{sub d}{sup -} and B-bar{sub s}{sup 0} {yields} D{sub d}{sup +}D{sub d}{sup -}* are of order (4 - 7) x 10-3. If both D-mesons in the final state are D*'s, we obtain branching ratios of order two times bigger.