Measuring $\sin (2β)$ in $B \to D^{*+}D^{*-}K_s$ Decays

We consider the possibility of measuring $\sin (2 \beta)$ in the KM unitarity triangle using the process $B^0 \to D^{*+}D^{*-}K_s$. This decay mode has a higher branching fraction (O(1%)) than the mode $B^0 \to D^{*+}D^{*-}$. We use the factorization assumption and heavy hadron chiral perturbation theory to estimate the branching fraction and polarization. The final states in the decay of $B^0 \to D^{*+} D^{*-} K_s$ are found to be dominantly in a single CP state and hence can be used to measure $\sin (2 \beta)$ without an angular analysis. Furthermore, examination of the $D^{*+} K_s$ mass spectrum may be the best way to experimentally find the broad $1^+$ p-wave $D_s$ meson.