Massive two-loop heavy particle diagrams

Two - loop sunset diagrams with three massive lines

In this paper, we consider the two-loop sunset diagram with two different masses, m and M , at spacelike virtuality q2 = −m2. We find explicit representations for the master integrals and an analytic result through O(ε) in d = 4 − 2ε space-time dimensions for the case of equal masses, m = M . PACS: 11.15.-q, 12.38.Bx

On the New Method of Computing Two-loop Massive Diagrams

Two-loop and n-loop vertex corrections for eikonal diagrams with massive partons

We present the ultraviolet poles and finite terms of two-loop vertex corrections for diagrams with massive partons in the eikonal approximation. We discover and prove that the results for a set of the corrections generalize to n-loop eikonal diagrams. These results will enhance theoretical understanding and allow greater calculational accuracy for the many partonic processes where the eikonal a...

Massive 3-loop Feynman Diagrams Reducible to SC

Massive 3-loop Feynman diagrams reducible to SC primitives of algebras of the sixth root of unity 1 Abstract In each of the 10 cases with propagators of unit or zero mass, the nite part of the scalar 3-loop tetrahedral vacuum diagram is reduced to 4-letter words in the 7-letter alphabet of the 1-forms := dz=z and ! p := dz= ,p , z, where is the sixth root of unity. Three diagrams yield only 3 !...

Algorithmic Calculation of Two-loop Feynman Diagrams *

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. The Taylor coefficients are obtained from the original diagram by differentiation and putting the external momenta equal to zero. It was demonstrated that by a certain conformal mapping and subsequent resummation by means of...