Evidence of $h_b(\text{2P})\to \hat{I}\yen (\text{1S})\hat{I}\cdot$ decay and search for $h_b(\text{1P,2P})\to \hat{I}\yen (\text{1S})\ddot{I}{€}^0$ with the Belle detector

Abstract

We report the first evidence for the $h_b(\text{2P})\to \hat{I}\yen (\text{1S})\hat{I}\cdot$ transition with a significance of $3.5$ standard deviations. The decay branching fraction is measured to be $\mathcal{B}[h_b(\text{2P})\to \hat{I}\yen (\text{1S})\hat{I}\cdot ]=(7.1{}_{-3.2}^{+3.7}\pm 0.8)\times 10^{-3}$, which is noticeably smaller than expected. We also set upper limits on $\ddot{I}{€}^0$ transitions of $\mathcal{B}[h_b(\text{2P})\to \hat{I}\yen (\text{1S})\ddot{I}{€}^0]<1.8\times 10^{-3}$, and $\mathcal{B}[h_b(\text{1P})\to \hat{I}\yen (\text{1S})\ddot{I}{€}^0]<1.8\times 10^{-3}$, at the $90\%$ confidence level. These results are obtained with a $131.4$~fb${}^{-1}$ data sample collected near the $\hat{I}\yen (\text{5S})$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider.

to be submitted to PRL