Next-to-leading order QCD and relativistic corrections to $Z\to J/\ddot{I}ˆ+\hat{I}\yen (nS)$

Guang-Yu Wang, Xu-Chang Zheng, Guang-Zhi Xu

In this paper, we calculate the decay widths and branching fractions for the decays $Z\to J/\ddot{I}ˆ+\hat{I}\yen (nS)$ ($n=1,2,3$) at future super $Z$ factory and at the CEPC/FCC-ee, including bo…