Hadronic top-quark pair production in association with two jets at   Next-to-Leading Order QCD
  We report on the calculation of the next-to-leading order QCD corrections to the production of ttbar pairs in association with two hard jets at the Fermilab TeVatron and CERN Large Hadron Collider. Results for the integrated and differential cross sections are given. The corrections with respect to leading order are negative and moderate. A study of the scale dependence of our NLO predictions indicates that the residual theoretical uncertainty, due to higher order corrections, is 21% for the TeVatron and 15% for the LHC. In case of the TeVatron, the forward-backward asymmetry of the top quark is calculated for the first time at next-to-leading order. With the inclusive selection of cuts, this asymmetry amounts to A_FB = -10.3% at leading order and A_FB = -4.6% at next-to-leading order. All results presented in this paper have been obtained with the help of the HELAC-NLO package. 
G. Bevilacqua, M. Czakon, C. G. Papadopoulos, M. Worek
hep-ph hep-ex