Inclusive productions of $J/\psi +{\eta }_c$ in $e^{+}{e}^{-}$ annihilation at Belle

Zhan Sun, Shu-Jian Qi, Ying-Zhao Jiang

We study $e^{+}{e}^{-}\to J/\psi +{\eta }_c+X$ at next-to-leading order (NLO) in ${\alpha }_s$ within the nonrelativistic QCD (NRQCD) framework to assess the color-octet (CO) mechanism at low energie…