Seminarium Teorii Oddziaływań Elementarnych

The latest developments in the recursive computation of multileg scattering amplitudes in QCD in the High Energy Factorization formalism are described. Then their phenomenological application to the description of inclusive 4 jet production at the LHC is presented. Particular emphasis is given to the search for Double Parton Scattering and to the observables and phase space constraints which can best highlight it in future data analyses. Finally, we briefly present an early attempt to constrain Double Parton Distribution functions.