Progress in top-pair production at hadron colliders
  We review recently derived NNLO QCD results for top-pair production at hadron colliders. We compare the size of the NNLO corrections in $q\bar q\to t\bar t+X$ with the LO and NLO ones, and address the question of convergence of perturbative series. We compare the NLO and NNLO K-factors for the Tevatron. 
Peter Baernreuther, Michal Czakon and Alexander Mitov
hep-ph