Measuring $\beta$ in $\overrightarrow{B}{D}^{\left(*\right)+}{D}^{\left(*\right)-}{K}_s$ decays

We consider the possibility of measuring both $\sin \left(2\mathrm{}\beta \right)$ and $\cos \left(2\mathrm{}\beta \right)$ in the KM unitarity triangle using the process $B^0\to D^{*+}{D}^{*-}{K}_s.$ This decay mode has a higher branching fraction $\left[O\right(1\%\left)\mathrm{}\right]$ 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 time dependent rate for $B^0\mathrm{}\left(t\right)\mathrm{}\to D^{*+}{D}^{*-}{K}_s$ can be used to measure $\sin \left(2\mathrm{}\beta \right)$ and $\cos \left(2\mathrm{}\beta \right).\mathrm{}$ 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.