First observation of exclusive ${\rm Y}(1S)$ and ${\rm Y}(2S)$ decays into light hadrons

Belle Collaboration, C. P. Shen, C. Z. Yuan +153

Using samples of 102 million ${\rm Y}(1S)$ and 158 million ${\rm Y}(2S)$ events collected with the Belle detector, we study exclusive hadronic decays of these two bottomonium resonances to the…