We report the results of the first search for the decay $B_s^0 \rightarrow \eta^\prime \eta$ using $121.4~\textrm{ fb}^{ -1}$ of data collected at the $\Upsilon(5S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. We observe no significant signal and set a 90\% confidence-level upper limit of %$7.1 \times 10^{ -5}$ $6.5 \times 10^{ -5}$ on the branching fraction of this decay.
Categories: hep-ex