Electromagnetic Production of Quarkonium in $Z^{0}$ decay

Abstract

The decay $Z^{0}\rightarrow Q+ \ell^{+}\ell^{-}$, where $Q$ is a $J^{PC}=1^{--}$ quarkonium state, has a very clean final state, which should make it easy to detect. The branching ratio of this mode is greater than $10^{-6}$ for $ρ$, $ϕ$, and $ψ$, indicating that these processes may be detectable at LEP.