Next-to-Next-to-Leading Order QCD Corrections to Higgs Boson Pair   Production
  We present the Higgs boson pair production cross section at next-to-next-to-leading order in QCD within the large top-mass approximation. Numerical results for the LHC are provided, finding an increase of O(20%) with respect to the previous order prediction and a substantial reduction in the scale dependence. We normalize our results using the full top- and bottom-mass dependence at leading order. 
Daniel de Florian and Javier Mazzitelli
hep-ph