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[Licence| Download | New Version Template] aecg_v1_0.tar.gz(101 Kbytes) | ||
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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_0Distribution 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. | ||

PACS: 11.15.Bt. | ||

Classification: 4.4. | ||

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. | ||

Solution method:The integrals depend on three internal masses and the external momentum squared p. The method is a combination of an accelerated expansion in 1/^{2}p in its (pretty large!) region of fast convergence and of a Runge-Kutta numerical solution of a system of linear differential equations.^{2} | ||

Running time:To obtain 4 Master Integrals on PC with 2 GHz processor it takes 3 μ s 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). |

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