Explorations of the top quark forward-backward asymmetry at the Tevatron

We consider the recent measurement of the top quark forward-backward asymmetry at the Fermilab Tevatron, which shows a discrepancy of slightly more than 2 sigma compared to the standard model prediction. We find that t-channel exchange of a color sextet or triplet scalar particle can explain the measurement, while leaving the cross section for t (t) over bar production within measured uncertainties. Such particles have good discovery prospects by study of the kinematic structure of t (t) over bar + jets at the LHC.