PROGRAM SUMMARY
Title of program:
MATAD
Catalogue identifier:
ADNG
Ref. in CPC:
134(2001)335
Distribution format: tar gzip file
Operating system: UNIX, FORM 2.3
Number of lines in distributed program, including test data, etc:
17497
Keywords:
Elementary particle physics, QCD, Three-loop computations,
Vacuum integrals, Computer algebra, Automation of computations.
Programming language used: FORM
Nature of problem:
Multi-loop integrals are needed for the evaluation of quantum
corrections. An important class of loop diagrams is covered by
so-called vacuum integrals which have no external momentum. MATAD can
analytically compute those one-, two- and three-loop vacuum integrals
where one mass scale is present.
Method of solution:
The method of integration-by-parts is used in order to obtain recurrence
relations which reduce complicated integrals to a small set of so-called
master integrals. They have to be evaluated once and for all. In
addition a user interface is provided which makes it easy to put in
complicated diagrams in a rather compact way.
Restrictions:
The restrictions on the complexity are given by the hardware limitations
of the computer and the limits on the size of the storage files inside
FORM [1].
Typical running time:
The runtime strongly depends on the complexity of the diagram under
consideration. It may vary from a few seconds to the order of a few
weeks.
References:
[1] J.A.M. Vermaseren, Symbolic Manipulation with FORM, (Computer
Algebra Netherlands, Amsterdam, 1991).