Flavor-Specific Inclusive B Decays to Charm

TL;DR

This paper measures specific B meson decay branching fractions, providing insights into the b -> c c_bar s process and its impact on the B semileptonic decay discrepancy, with implications for particle physics models.

Contribution

It offers new measurements of B decay branching fractions and discusses their implications for the B semileptonic decay problem, improving understanding of underlying decay mechanisms.

Findings

Br(b -> c c_bar s) = (21.9 ± 3.7)%

Br(b -> s g) < 6.8% at 90% c.l.

Br(D^0 -> K^- π^+) = (3.69 ± 0.20)%

Abstract

We have measured the branching fractions for B -> D_bar X, B -> D X, and B -> D_bar X \ell^+ \nu, where ``B'' is an average over B^0 and B^+, ``D'' is a sum over D^0 and D^+, and``D_bar'' 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^- \pi^+) = (3.69 $\pm$ 0.20)%. Implications for the ``B semileptonic decay problem'' (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.