We present a new and
unique measurement of the branching fractions of b
hadrons to states with 0, 1, and 2 open charm hadrons,
using a sample of 350,000 Z's collected during the
SLD/SLC 97-98 run. The analysis takes advantage of the
excellent vertexing resolution of the VXD3, a
pixel-based CCD vertex detector, which allows the
separation of B and cascade D decay vertices. Analysis
of the decay length distributions for each of the 1-,
2-, and 3-secondary-vertex topologies allows the
extraction of the inclusive branching ratios $BR(b
\rightarrow 0D)$ and $BR(b \rightarrow 2D)$ with
statistical errors of less than 0.015. |