$B_s$ Mixing via $\psi K^*$

Abstract

The decay mode $B_s\to\psi \overline{K}^*$ is suggested as a very good way to measure the $B_s$ mixing parameter $x_s$. These decays can be gathered using a $\psi\to\ell^+\ell^-$ trigger. This final state has a well resolved four track decay vertex, useful for good time resolution and background rejection.