Observation of ${\rm Y}(4S)\to {\eta }^{\prime }{\rm Y}(1S)$

Belle Collaboration, E. Guido, R. Mussa +168

We report the first observation of the hadronic transition ${\rm Y}(4S)\to {\eta }^{\prime }{\rm Y}(1S)$, using 496 fb${}^{-1}$ data collected at the ${\rm Y}(4S)$ resonance with the Belle detector at the KEKB asymme…