Elsevier Science Home
Computer Physics Communications Program Library
Full text online from Science Direct
Programs in Physics & Physical Chemistry
CPC Home

[Licence| Download | New Version Template] abbx_v2_0.gz(24 Kbytes)
Manuscript Title: Algebraic reduction of one-loop Feynman diagrams to scalar integrals II.
Authors: R.G. Stuart, A. Gongora-T
Program title: LERG-I
Catalogue identifier: ABBX_v2_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 56(1990)337
Programming language: Reduce.
Computer: IBM 4381.
Keywords: General purpose, Diagramatic expansions, Gauge theories, Renormalizable theories, Scalar integrals, One-loop integrals, Feynman diagrams, Dimensional Regularization, Reduce.
Classification: 4.4, 5.

Nature of problem:
Expressions obtained in the calculation of one-loop radiative processes in high energy physics are generally simplified by expressing them in terms of scalar integrals. LERG-I makes the reduction from form factors assocated with the various possible Lorentz tensors occuring in the problem.

Solution method:
The program makes use of identities that, in the context of dimensional regularization, relate the various form factors to one and other in a hierarchical fashion. The end result is that all form factors are finally defined in terms of scalar integrals.

Processes with up to four external particles can be treated. Machine storage is usually the only limitation.

Running time:
Depends heavily on the complexity of the problem. The test run took 40 CPU s. To initialize the C4 form factors with all arguments different and non-zero takes 259 CPU s.