The tauola-photos-F environment for the TAUOLA and PHOTOS packages, release II

Abstract

We present the system for maintaining the versions of two packages: the TAUOLA of τ-lepton decay and PHOTOS for radiative corrections in decays. The following features can be chosen in an automatic or semi-automatic way: (1) format of the common block HEPEVT; (2) version of the physics input (for TAUOLA): as published, as initialized by the CLEO collaboration, as initialized by the ALEPH collaboration (it is suggested to use this version only with the help of the collaboration advice), new optional parametrization of matrix elements in 4 π decay channels; (3) type of application: stand-alone, universal interface based on the information stored in the HEPEVT common block including longitudinal spin effects in the elementary Z / γ ∗ → τ + τ − process, extended version of the standard universal interface including full spin effects in the H / A → τ + τ − decay, interface for KKMC Monte Carlo, (4) random number generators; (5) compiler options. The last section of the paper contains documentation of the programs updates introduced over the last two years. Program summary Title of program: tauola-photos-F, release II Catalogue identifier:ADXO_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADXO_v1_0 Programs obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Computer: PC running GNU/Linux operating system Programming languages and tools used: CPP: standard C-language preprocessor, GNU Make builder tool, also FORTRAN compiler No. of lines in distributed program, including test data, etc.: 194 118 No. of bytes in distributed program, including test data, etc.:2 481 234 Distribution format: tar.gz Catalogue identifier:ADXO_v2_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADXO_v2_0 No. of lines in distributed program, including test data, etc.:308 235 No. of bytes in distributed program, including test data, etc.:2 988 363 Distribution format:tar.gz Does the new version supersede the previous version:Yes Nature of the physical problem: The code of Monte Carlo generators often has to be tuned to the needs of large HEP Collaborations and experiments. Usually, these modifications do not introduce important changes in the algorithm, but rather modify the initialization and form of the hadronic current in τ decays. The format of the event record ( HEPEVT common block) used to exchange information between building blocks of Monte Carlo systems often needs modification. Thus, there is a need to maintain various, slightly modified versions of the same code. The package presented here allows the production of ready-to-compile versions of TAUOLA [S. Jadach, Z. Wa̧s, R. Decker, J.H. Kühn, Comput. Phys. Comm. 76 (1993) 361; A.E. Bondar, et al., Comput. Phys. Comm. 146 (2002) 139] and PHOTOS [E. Barberio, Z. Wa̧s, Comput. Phys. Comm. 79 (1994) 291] Monte Carlo generators with appropriate demonstration programs. The new algorithm, universal interface of TAUOLA to work with the HEPEVT common block, is also documented here. Finally, minor technical improvements of TAUOLA and PHOTOS are also listed. Method of solution: The standard UNIX tool: the C-language preprocessor is used to produce a ready-to-distribute version of TAUOLA and PHOTOS code. The final FORTRAN code is produced from the library of ‘pre-code’ that is included in the package. Reasons for new version: The functionality of the version of TAUOLA and PHOTOS changed over the last two years. The changes, and their reasons, are documented in Section 9, and our new papers cited in this section. Additional comments: The updated version includes new features described in Section 9 of the paper. PHOTOS and TAUOLA were first submitted to the library as separate programs. Summary details of these previous programs are obtainable from the CPC Program Library. Typical running time: Depends on the speed of the computer used and the demonstration program chosen. Typically a few seconds.