Pavel Krokovny (Budker Institute of Nuclear Physics (RU))
We report the results of a study of 352 million $\Upsilon(4S)$ decays in which the final state $\eta \Upsilon(1S)$ is observed. We observe two transitions, $\Upsilon(4S) \to \eta \Upsilon(1S)$ and $\Upsilon(1D) \to \eta \Upsilon(1S)$. The results on a search for $\chi_b (3P)$ spin triplet bottomonium states are presented as well. The data are produced by the KEKB $e^+e^-$ collider and collected by the Belle detector.
Prof. Youngjoon Kwon (Yonsei University)