https://doi.org/10.1140/epjc/s2004-01974-2
theoretical physics
Laurent series expansion of sunrise-type diagrams using configuration space techniques
1
Institut für Physik, Johannes-Gutenberg-Universität, Staudinger Weg 7, 55099, Mainz, Germany
2
Füüsika-Keemiateaduskond, Tartu Ülikool, Tähe 4, 51010, Tartu, Estonia
3
Institute for Nuclear Research of the Russian Academy of Sciences, 117312, Moscow, Russia
We show that configuration space techniques can be used to efficiently calculate the complete Laurent series 
-expansion of sunrise-type diagrams to any loop order in D-dimensional space-time for any external momentum and for arbitrary mass configurations. For negative powers of the results are obtained in analytical form. For positive powers of including the finite 
contribution the result is obtained numerically in terms of low-dimensional integrals. We present general features of the calculation and provide exemplary results up to five-loop order which are compared to available results in the literature.
© Springer-Verlag, 2004
