DOI 10.1007/s100529800721
Calculation of infrared-divergent Feynman diagrams with zero mass threshold
J. Fleischer1 - V.A. Smirnov2 - A. Frink3 - J. Körner3 - D. Kreimer3 - K. Schilcher4, - J.B. Tausk3
1 Fakultät für Physik, Universität Bielefeld,
D-33615 Bielefeld , Germany (e-mail:
fleischer@physik.uni-bielefeld.de)
2 Nuclear Physics Institute of Moscow State University,
119899 Moscow, Russian Federation
(e-mail:
smirnov@theory.npi.msu.su)
3 Institut für Physik, Universität Mainz,
D-55099 Mainz, Germany (e-mail:
frink@dipmza.physik.uni-mainz.de)
4 Department of Physics, University of California,
San Diego, La Jolla, CA 92093-0319 USA
Received: 22 April 1997 / Published online: 20 February 1998
Abstract
Two-loop vertex Feynman diagrams with infrared and
collinear divergences are investigated
by two independent methods.
On the one hand, a method of calculating Feynman diagrams from their
small momentum expansion [1] extended to diagrams with zero
mass thresholds [2] is applied. On the other hand, a
numerical method based on a two-fold integral representation is used
[3], [4].
The application of the latter method is possible by using
lightcone coordinates in the parallel space. The numerical
data obtained with the two methods are in impressive agreement.
Copyright Springer-Verlag
