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.

Restrictions:
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.