  Parity-odd asymmetries in the decay angular distribution of a W boson
produced with a hard jet in p\bar{p} collisions arise only from QCD
rescattering effects. If observed, these asymmetries will provide a first
demonstration that perturbative QCD calculation is valid for the absorptive
part of scattering amplitudes. We propose a simple observable to measure these
asymmetries and perform realistic Monte Carlo simulations at Tevatron energies.
It is shown that the Tevatron Run-II should provide sufficient statistics to
test the prediction.
