MC-TESTER v. 1.23: A universal tool for comparisons of Monte Carlo predictions for particle decays in high energy physics

Abstract

Theoretical predictions in high energy physics are routinely provided in the form of Monte Carlo generators. Comparisons of predictions from different programs and/or different initialization set-ups are often necessary. MC-TESTER can be used for such tests of decays of intermediate states (particles or resonances) in a semi-automated way.Since 2002 new functionalities were introduced into the package. In particular, it now works with the HepMC event record, the standard for C++ programs. The complete setup for benchmarking the interfaces, such as interface between τ-lepton production and decay, including QED bremsstrahlung effects is shown. The example is chosen to illustrate the new options introduced into the program. From the technical perspective, our paper documents software updates and supplements previous documentation.As in the past, our test consists of two steps. Distinct Monte Carlo programs are run separately; events with decays of a chosen particle are searched, and information is stored by MC-TESTER. Then, at the analysis step, information from a pair of runs may be compared and represented in the form of tables and plots.Updates introduced in the progam up to version 1.24.3 are also documented. In particular, new configuration scripts or script to combine results from multitude of runs into single information file to be used in analysis step are explained. PROGRAM UPDATE SUMMARYTitle of the program: MC-TESTER, version 1.23 and version 1.24.3 Tested on various platforms and operating systems: Linux SLC 4.6 and SLC 5, Fedora 8, Ubuntu 8.2 etc. Programming languages used: C++, FORTRAN77 Tested and compiled with: gcc 3.4.6, 4.2.4 and 4.3.2 with g77/gfortran Size of the package: 23.4 MB directory including example programs (6.5 MB compressed distribution archive), without ROOT libraries. Additional disk space required: Depends on the analyzed particle: 14.4 MB in the case of τ lepton decays (30 decay channels, 594 histograms, 73-pages booklet).

Resonance chiral Lagrangian currents andτdecay Monte Carlo

“…Many of the results collected there were obtained using MC-TESTER [57]. The distributions can be thus easily used for benchmarking any other Monte Carlo program independently if it is used for simulations coded in C++ or FORTRAN, provided that event record such as HEPEVT or HepMC [122] is used.…”

“…2. We point the reader to the web page [28], for the booklet of comparisons obtained with MC-TESTER [57]. The figures for dΓ/dq 2 spectrum from Monte Carlo and analytical calculations are also available from the plots of the Web page [28].…”

“…It is of great importance to include them in the twomeson decays, because otherwise the right normalization at the peak is clearly lost and the curve would go systematically below the data in the resonance region 57 . This effect is certainly much smaller for the three-meson τ decays, where nonetheless it can show up in the two-particle invariant mass distributions in particular regions of phase space, where our calculation is particularly far from experimental data, see Fig.…”

New hadronic currents in TAUOLA: for confrontation with the experimental data

“…[13]. As in the past, the program main purpose remains benchmarking the decay part of different Monte Carlo chains.…”

“…For that purpose automated tests of MC-TESTER were prepared [12]. New functionalities were introduced into the testing package [13]. In particular, it works now with the HepMC event record, the standard of C++ programs and the spectrum of available tests is enriched.…”