GRK 1694: Elementary Particle Physics at Highest Energy and highest Precision

Unitary Methods for one-loop calculations

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  • lecturer:

    Prof. Kirill Melnikov

    Johns Hopkins University, KIT Distinguished Research Fellow


Although the field of one-loop computations is mature, parton multiplicities in hard LHCevents are so high that traditional computational techniques become inefficient. Recently new approaches based on unitarity have been developed for calculating one-loop scattering amplitudes in quantum field theory. These methods are especially suitable for the description of multi-particle processes in QCD and are amenable to numerical implementations. They are also quite peculiar in that on-shell tree scattering amplitudes, rather than Feynman diagrams, can be used as an input. I will discuss the new methods in a pedagogical fashion and will explain conceptual and technical aspects of the new methods.