Measurement of Branching Ratios for ${\eta }_c$ Hadronic Decays

J. Z. Bai

In a sample of 58 million $J/\psi$ events collected with the BES II detector, the process J/$\psi \to \gamma {\eta }_c$ is observed in five decay channels: ${\eta }_c\to K^{+}{K}^{-}{\pi }^{+}{\pi }^{-}$, ${\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$, $K^\…