Programs in Physics & Physical Chemistry
|[Licence| Download | New Version Template] aecg_v1_0.tar.gz(101 Kbytes)|
|Manuscript Title: BOKASUN: a fast and precise numerical program to calculate the Master Integrals of the two-loop sunrise diagrams|
|Authors: Michele Caffo, Henryk Czyz, Michal Gunia, Ettore Remiddi|
|Program title: BOKASUN|
|Catalogue identifier: AECG_v1_0|
Distribution format: tar.gz
|Journal reference: Comput. Phys. Commun. 180(2009)427|
|Programming language: FORTRAN77.|
|Computer: Any computer with a Fortran compiler accepting FORTRAN77 standard. Tested on various PC's with LINUX.|
|Operating system: LINUX.|
|RAM: 120 kbytes|
|Keywords: Feynman diagrams, sunrise diagram, numerical evaluation.|
Nature of problem:
Any integral arising in the evaluation of the two-loop sunrise Feynman diagram can be expressed in terms of a given set of Master Integrals, which should be calculated numerically. The program provides a fast and precise evaluation method of the Master Integrals for arbitrary (but not vanishing) masses and arbitrary value of the external momentum.
The integrals depend on three internal masses and the external momentum squared p2. The method is a combination of an accelerated expansion in 1/p2 in its (pretty large!) region of fast convergence and of a Runge-Kutta numerical solution of a system of linear differential equations.
To obtain 4 Master Integrals on PC with 2 GHz processor it takes 3 μs for series expansion with pre-calculated coefficients, 80 μs for series expansion without pre-calculated coefficients, from a few seconds up to a few minutes for Runge-Kutta method (depending on the required accuracy and the values of the physical parameters).
|Disclaimer | ScienceDirect | CPC Journal | CPC | QUB|