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

TL;DR

The paper proposes using the decay mode $B_s o ext{ extpsi} ext{ extbar} K^*$ to measure the $B_s$ mixing parameter $x_s$, leveraging its clean decay signature for precise measurements.

Contribution

It introduces a new decay channel for measuring $B_s$ mixing, emphasizing its advantages in trigger efficiency and vertex resolution.

Findings

Decay mode $B_s o ext{ extpsi} ext{ extbar} K^*$ is effective for $x_s$ measurement.

Good time resolution and background rejection achievable with this decay.

Potential for improved $B_s$ mixing parameter determination.

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.