SecDec: a versatile tool for multi-loop/leg calculations
by
Jonathon Carter(University of Durham)
→
Europe/Berlin
313
313
Description
I present sector decomposition as a method to extract singularities from
multi-dimensional polynomial parameter integrals in a universal way. I show how
these integrals can be expanded as a Laurent series in the regularisation
parameter, and that the coefficients of this series are numerically integrable
parameter integrals over the unit hypercube. I demonstrate how integrals of this
type arise in multi-loop integrals and in phase space integrals involving
massless particles.
Then I present the program 'SecDec', and demonstrate how it performs the above
procedure in an automated way. I talk about potential numerical instabilities
for complicated calculations, and how these are dealt with in a robust and
generic way. I present results and timings for a number of cutting edge
multi-loop integrals, e.g. 2-loop box integrals entering top quark pair
production at NNLO, 3loop vertex functions or 4-loop propagators.
