Final Report Summary - SAMURAI-APPS (Precision study of W bosons pair production in association with jets at High Energy Colliders) The researcher's activity at CERN has been devoted to the computation of precise predictions for event distributions at the Large Hadron Collider.The recent discovery of a new resonance at the LHC at CERN of mass 125 GeV is the result of the efforts in the construction and operation of the accelerator and of the detectors as well as of the efficiency in the implementation and interpretation of very detailed analyzes on the large amount of informations collected. Now the aim is to have detailed measurements of all the decay branching ratios of the novel particle while of course search for other new particles in all the mass regions accessible.The first question is to establish if the new resonance is or not the Higgs boson. In this scenario it is clear that the help of automated tools for the simulation of signals and backgrounds coming from the Standard Model or beyond is desirable and is now possible including Quantum Chromo Dynamic (QCD) corrections up to the NLO accuracy in the perturbative strong coupling constant. The QCD corrections at Hadron Colliders play of course the main role and several fully automated tools exist based on the leading order prediction in perturbation theory for the hard scattering processes. The Next to Leading Order (NLO) hard QCD corrections, being in general quite sizable, are also needed to get predictions with a theoretical error comparable with the accuracy attainable at the LHC.