Using multidimensional complex analysis to evaluate Feynman diagrams

par Dr David Greynat (IFIC Valencia)

vendredi 18 avr. 2008, 14:30 → 15:30 Europe/Paris

Amphi de Recherche

In a previous work, we showed how the Mellin-Barnes representation of Feynman diagrams with one scale (i.e. one ratio of masses and/or momenta), when combined with the converse mapping theorem, allows to simplify a lot the analytical evaluation of as many terms as wanted of their asymptotic expansions in powers and logs of this scale. Recently, we extended this method to Feynman diagrams containing several scales. For this, we used multidimensional complex analysis and especially multidimensional residues theory. This very general technique can be applied to different domains. We illustrate it by evaluating analytically a specific class of 5-loops QED contributions to the anomalous magnetic moment of the muon, involving the masses of the electron, muon and tau.