Flavor-Specific Inclusive B Decays to Charm

Abstract

We have measured the branching fractions for B -> D_bar X, B -> D X, and B -> D_bar X \ell^+ ν, where ``B&#39;&#39; is an average over B^0 and B^+, ``D&#39;&#39; is a sum over D^0 and D^+, and``D_bar&#39;&#39; is a sum over D^0_bar and D^-. From these results and some previously measured branching fractions, we obtain Br(b -> c c_bar s) = (21.9 $\pm$ 3.7)%, Br(b -> s g) < 6.8% @ 90% c.l, and Br(D^0 -> K^- π^+) = (3.69 $\pm$ 0.20)%. Implications for the ``B semileptonic decay problem&#39;&#39; (measured branching fraction being below theoretical expectations) are discussed. The increase in the value of Br(b -> c c_bar s) due to $B -> D X$ eliminates 40% of the discrepancy.