Feynman Integral Evaluation by a Sector decomposiTion Approach (FIESTA)

We present a new program performing the sector decomposition and integrating the expression afterwards. The program takes a set of propagators and a set of indices as input and returns the epsilon-expansion of the corresponding integral.Program summaryProgram title: FIESTACatalogue identifier: AECP_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AECP_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: GPL v2No. of lines in distributed program, including test data, etc.: 88 281No. of bytes in distributed program, including test data, etc.: 6 153 480Distribution format: tar.gzProgramming language: Wolfram Mathematica 6.0 [3] and CComputer: from a desktop PC to supercomputerOperating system: Unix, Linux, WindowsRAM: depends on the complexity of the problemClassification: 4.4, 4.12, 5, 6.5External routines: QLink [1], Vegas [2]Nature of problem: The sector decomposition approach to evaluating Feynman integrals falls apart into the sector decomposition itself, where one has to minimize the number of sectors; the pole resolution and epsilon expansion; and the numerical integration of the resulting expression.Solution method: The sector decomposition is based on a new strategy. The sector decomposition, pole resolution and epsilon-expansion are performed in Wolfram Mathematica 6.0 [3]. The data is stored on hard disk via a special program, QLink [1]. The expression for integration is passed to the C-part of the code, that parses the string and performs the integration by the Vegas algorithm [2]. This part of the evaluation is perfectly parallelized on multi-kernel computers.Restrictions: The complexity of the problem is mostly restricted by the CPU time required to perform the evaluation of the integral, however there is currently a limit of maximum 11 positive indices in the integral; this restriction is to be removed in future versions of the code.Running time: Depends on the complexity of the problem.References:[1] http://qlink08.sourceforge.net, open source.[2] G.P. Lepage, The Cornell preprint CLNS-80/447, 1980.[3] http://www.wolfram.com/products/mathematica/index.html2.