Updated Cross Section Measurement of $e^{+}{e}^{-}\to K^{+}{K}^{-}J/\ddot{I}ˆ$ and $K_S^0{K}_S^{0}J/\ddot{I}ˆ$ via Initial State Radiation at Belle

Abstract

The cross sections of the processes $e^{+}{e}^{-}\to K^{+}{K}^{-}J/\ddot{I}ˆ$ and $K_S^0{K}_S^{0}J/\ddot{I}ˆ$ are measured via initial state radiation at center-of-mass energies between the threshold and 6.0~GeV using a data sample of 980~fb${}^{-1}$ collected with the Belle detector on or near the $\hat{I}\yen (nS)$ resonances, where $n=$1, 2, ..., 5. The cross sections for $e^{+}{e}^{-}\to K^{+}{K}^{-}J/\ddot{I}ˆ$ are at a few pb level and the average cross section for $e^{+}{e}^{-}\to K_S^0{K}_S^{0}J/\ddot{I}ˆ$ is $1.8\pm 0.6(stat.)\pm 0.3(syst.)$~pb between 4.4 and 5.2~GeV. All of them are consistent with previously published results with improved precision. A search for resonant structures and associated intermediate states in the cross section of the process $e^{+}{e}^{-}\to K^{+}{K}^{-}J/\ddot{I}ˆ$ is performed.

14 pages, 7 figures