CALCULATION OF 2-LOOP VERTEX FUNCTIONS FROM THEIR SMALL MOMENTUM EXPANSION

Fleischer J. CALCULATION OF 2-LOOP VERTEX FUNCTIONS FROM THEIR SMALL MOMENTUM EXPANSION. In: International Journal of Modern Physics C. INTERNATIONAL JOURNAL OF MODERN PHYSICS C-PHYSICS AND COMPUTERS. Vol 6. WORLD SCIENTIFIC PUBL CO PTE LTD; 1995: 495-501.In a recent paper(1) a new powerful method to calculate Feynman diagrams was proposed. It consists in setting up a Taylor series expansion in the external momenta squared, a certain conformal mapping and subsequent resummation by means of Pade approximants. I present numerical examples