  Motivated by the recent unexpected large forward-backward asymmetry (FBA) of
the top quark observed by D$\O$ and CDF at the Tevatron, we investigate a
possible explanation for the anomaly within the framework of diquark models.
Unlike other mechanisms induced by s-channel or t-channel, the top-quark pair
production in the diquark models is dictated by the u-channel diagram. We find
that the color-triplet diquark can generate the FBA of 20% when the constraint
from the cross section of the top-quark pair production is taken into account.

High Energy Physics - Phenomenology;High Energy Physics - Experiment