Effective field theory for top physics

We study the top forward-backward asymmetry (FBA $\equiv A_{\rm FB}$) reported by CDF and D0 Collaborations in the effective lagrangian approach. Using dimension-6 effective largrangians for $q \bar{q} \rightarrow t \bar{t}$, we study the $t\bar{t}$ production cross section and the $A_{\rm FB}$, and a few observables: the FB spin-spin correlation that is strongly correlated with the $A_{\rm FB}$, and longitudinal top polarization as a new probe of chiral structures for possible new physics scenarios.