High Energy Seminar :"Novel methods for multi-loop scattering amplitudes"

Mon, 20/05/201914:30-16:00
Kaplun seminar room
Lecturer : Dr Kasper Larsen (University of Southampton)
Abstract :
The computation of multi-loop scattering amplitudes is crucial for precision LHC physics. In this talk I will discuss novel methods for their evaluation. The main emphasis will be on a new and highly efficient approach for generating so-called integration-by-parts (IBP) reductions, which form the core of multi-loop computations. These are linear relations which allow to express any amplitude in a basis of loop integrals. The approach makes use of ideas from modern unitarity and from computational algebraic geometry, which I will explain. I then demonstrate the power of the approach by performing fully analytically the IBP reductions relevant for two-loop five-gluon scattering in QCD, which are well beyond the capabilities of publicly available IBP solvers.