QCDMAPT_F: Fortran version of QCDMAPT package

The QCDMAPT program package facilitates computations in the framework of dispersive approach to Quantum Chromodynamics. The QCDMAPT_F version of this package enables one to perform such computations with Fortran, whereas the previous version was developed for use with Maple system. The QCDMAPT_F package possesses the same basic features as its previous version. Namely, it embodies the calculated explicit expressions for relevant spectral functions up to the four-loop level and the subroutines for necessary integrals. New version program summary Program title: QCDMAPT_F Catalogue identifier: AEGP_v2_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEGP_v2_0.html Program obtainable from: CPC Program Library. Queen's University. Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 10 786 No. of bytes in distributed program, including test data, etc.: 332 329 Distribution format: tar.gz Programming language: Fortran 77 and higher Computer: Any which supports Fortran 77 Operating system: Any which supports Fortran 77 Classification: 11.1, 11.5, 11.6 External routines: MATHLIB routine RADAPT (D102) from CERNLIB Program Library [1] Catalogue identifier of previous version: AEGP_v1_0 Journal reference of previous version: Comput. Phys. Comm. 181 (2010) 1769 Does the new version supersede the previous version?: No. This version provides an alternative to the previous, Maple, version. Nature of problem: A central object of the dispersive (or analytic) approach to Quantum Chromodynamics [2,3] is the so-called spectral function, which can be calculated by making use of the strong running coupling. At the one-loop level the latter has a quite simple form and the relevant spectral function can easily be calculated. However, at the higher loop levels the strong running coupling has a rather cumbersome structure. Here, the explicit calculation of corresponding spectral functions represents a somewhat complicated task (see Section 3 and Appendix B of Ref. [4]), whereas their numerical evaluation requires a lot of computational resources and essentially slows down the overall computation process. Solution method: The developed package includes the calculated explicit expressions for relevant spectral functions up to the four-loop level and the subroutines for necessary integrals. Reasons for new version: The previous version of the package (Ref. [4]) was developed for use with Maple system. The new version is developed for Fortran programming language. Summary of revisions: The QCDMAPT_F package consists of the main program (QCDMAPT_F.f) and two samples of the file containing the values of input parameters (QCDMAPT_F.i1 and QCDMAPT_F.i2). The main program includes the definitions of relevant spectral functions and subroutines for necessary integrals. The main program also provides an example of computation of the values of (M)APT spacelike/timelike expansion functions for the specified set of input parameters and (as an option) generates the output data files with values of these functions over the given kinematic intervals. Additional comments: For the proper functioning of QCDMAPT_F package, the MATHLIB CERNLIB library [1] has to be installed. Running time: The running time of the main program with sample set of input parameters specified in the file QCDMAPT_F.i2 is about a minute (depends on CPU).