First observation of $B_s^0\to J/\psi \eta$ and $B_s^0\to J/\psi {\eta }^{\prime }$

Jin Li

We report first observations of $B_s^0\to J/\psi \eta$ and $B_s^0\to J/\psi {\eta }^{\prime }$. The results are obtained from 121.4 fb^{-1} of data collected at the ${\rm Y}(5S)$ resonance with the Belle detector…