NNLO corrections to top pair production at hadron colliders: the quark-gluon reaction

A bstract We compute the next-to-next-to-leading order QCD correction to the total inclusive top pair production cross-section in the reaction qg→ tt̄+X . We find moderate O (1%) correction to central values at both Tevatron and LHC. The scale variation of the cross-section remains unchanged at the Tevatron and is significantly reduced at the LHC. We find that recently introduced approximation based on the high-energy limit of the top pair cross-section significantly deviates from the exact result. The results derived in the present work are included in version 1.4 of the program Top++. Work towards computing the reaction gg→ tt̄+X is ongoing.