Using $420{\mathrm{pb}}^{-1}$ of data collected on the ${\rm Y}(5S)$ resonance with the CLEO III detector, we reconstruct $B$ mesons in 25 exclusive decay channels to measure or set upper limits on the decay rate of ${\rm Y}(5S)$ into $B$ meson final states. We measure the inclusive $B$ cross section to be $\sigma \mathbf{(}{\rm Y}(5S)\to B\overline{B}(X)\mathbf{)}=(0.177\pm 0.030\pm 0.016)\mathrm{nb}$ and make the first measurements of the production rates of $\sigma \mathbf{(}{\rm Y}(5S)\to B^{*}{\overline{B}}^{*}\mathbf{)}=(0.131\pm 0.025\pm 0.014)\mathrm{nb}$ and $\sigma \mathbf{(}{\rm Y}(5S)\to B{\overline{B}}^{*}\mathbf{)}=(0.043\pm 0.016\pm 0.006)\mathrm{nb}$, respectively. We set 90% confidence level limits of $\sigma \mathbf{(}{\rm Y}(5S)\to B\overline{B}\mathbf{)}<0.038\mathrm{nb}$, $\sigma \mathbf{(}{\rm Y}(5S)\to B^{(*)}{\overline{B}}^{(*)}\pi \mathbf{)}<0.055\mathrm{nb}$ and $\sigma \mathbf{(}{\rm Y}(5S)\to B\overline{B}\pi \pi \mathbf{)}<0.024\mathrm{nb}$. We also extract the most precise value of the $B_s^{*}$ mass to date, $M(B_s^{*})=(5411.7\pm 1.6\pm 0.6)\mathrm{MeV}/c^2$.

• Received 27 January 2006

DOI:https://doi.org/10.1103/PhysRevLett.96.152001