Color-Octet Quarkonium Production at the $Z$ Pole

The direct production rate of $J/\psi$ via the color-octet mechanism is calculated at the $Z$ resonance. The color-octet production process $Z\to J/\psi q \bar q$ is shown to have a substantial branching ratio as well as a distinctive energy spectrum, which can be used as a powerful tool to distinguish from the color-singlet direct production of the $J/\psi$.