How to Observe the Interference Effects of Top quark polarizations at Tevatron

Using a simple analytic expression for $q \bar{q}, g g \rightarrow t \bar{t} \rightarrow b W^+ \bar{b} W^- \rightarrow b \bar{l} \nu_l \bar{b} l' \bar{\nu_{l'}}$ with the interference effects due to the polarizations of the $t$ and $\bar{t}$, we demonstrate how the effects can be measured at Tevatron at $3\sigma$ level.