Study of $e^{+}{e}^{-}\to \hat{I}\yen (1S,2S)\hat{\mathrm{I}}\cdot$ and $e^{+}{e}^{-}\to \hat{I}\yen (1S)\hat{\mathrm{I}}{\cdot }^{\prime }$ at $\sqrt{s}=10.866$ GeV with the Belle detector

Abstract

We report the first observation of the processes $e^{+}{e}^{-}\to \hat{I}\yen (1S,2S)\hat{\mathrm{I}}\cdot$ at $\sqrt{s}=10.866$~GeV with a $10.2\ddot{I}ƒ$ and $16.5\ddot{I}ƒ$ significance respectively. The measured Born cross sections are $\ddot{I}ƒ(e^{+}{e}^{-}\to \hat{I}\yen (2S)\hat{I}\cdot )=2.07\pm 0.21\pm 0.19$~pb, and $\ddot{I}ƒ(e^{+}{e}^{-}\to \hat{I}\yen (1S)\hat{\mathrm{I}}\cdot )=0.42\pm 0.08\pm 0.04$~pb. We also set the upper limit on the cross section of the process $e^{+}{e}^{-}\to \hat{I}\yen (1S)\hat{\mathrm{I}}{\cdot }^{\prime }$ to be $\ddot{I}ƒ(e^{+}{e}^{-}\to \hat{I}\yen (1S)\hat{\mathrm{I}}{\cdot }^{\prime })<0.035$~pb at $90\%$ CL. The results are obtained with the data sample collected with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider in the energy range from $10.63$~GeV to $11.02$~GeV.

to be submitted to PRD