Modern methods for Scattering Amplitudes in gauge theories
The calculation of scattering amplitudes has been playing a very important role in the physics of the LHC. In particular, more accuracy is required to compare our theoretical predictions with the experiments. In this course, I plan to focus on modern techniques for the calculation of tree and multi-loop level amplitudes. In particular, the latter are part of the main ingredients to perform a Next-to-Next-to-Leading order (NNLO) computation, which currently is the main target of the physics community.
Content of the course:
• Computational techniques of scattering amplitudes: QCD scattering amplitudes, colourordered amplitudes, spinor-helicity formalism, momentum twistor variables, recursive relations.
• On-shell methods: Britto-Cachazo-Feng-Witten recursive relation, untarity of the S-matrix, optical theorem, generalised unitarity, quadruple cut.
• Feynman integrals: Passarino-Veltman reduction, Loop-tree duality, master integrals, differential equations for master integrals.
• Integrand reduction methods for multi-scattering amplitudes: Ossola-Papadopoulos-Pittau method, adaptive integrand decomposition.