Polarization Correlations in Muon Pair Production in the Electroweak Model

Explicit field theory computations are carried out of the joint probabilities associated with spin correlations of $\mu^{-}\mu^{+}$ produced in $e^{-}e^{+}$ collision in the standard electroweak model to the leading order. The derived expressions are found to depend not only on the speed of the $e^{-}e^{+}$ pair but also on the underlying couplings. These expressions are unlike the ones obtained from simply combining the spins of the relevant particles which are of kinematical nature. It is remarkable that these explicit results obtained from quantum field theory show a clear violation of Bell's inequality.