A new method of determining |V_(ub)| by the processes bar{B} to rho l bar{ν} and bar{B} to K^* l lbar

The differential decay width of the process $\bar{B} \rightarrow \rho l \bar{\nu}$ is related to that of the process $\bar{B} \rightarrow K^* l \lbar$ by using $SU(3)$-flavor symmetry and the heavy quark symmetry. The ratio of the Kobayashi-Maskawa matrix elements is obtained in the zero recoil limit of $\rho$ and $K^*$, allowing a determination of $|V_{ub}|$.