On the Observation of Top Spin Correlation Effect at Tevatron

We propose to observe the top spin correlation effect at Tevatron through the measurement of the correlated asymmetries of the charged lepton momenta using the dilepton decay events of top and anti-top quark pairs. The possibility of reconstructing the events and observing the asymmetries at 3$\sigma$ level with projected luminosity of the Tevatron for Run II is demonstrated by simulation. The effect can provide the first direct measurement of the spin of a quark.