Simulation Project Leaders Meeting 26-June-2012 ==== Attendees (virtual meeting) John Apostolakis (JA), Andrea Dotti (AD), Alfredo Ferrari (AF), Witold Pokorski (WP), Rob Veenhof (RV), Gabriele Cosmo (GC). --------------------------------------------------------------------- ==== Minutes - Witold Pokorski replaces Andrea Dotti in the leadership of the Physics Validation project, as of July 2012. We all thanks Andrea for the excellent contribution given to the Simulation Project and professionalism shown during the past two years. We all hope to have occasions to communicate and collaborate again in the future. --------------------------------------------------------------------- ==== Simulation physics validation & framework - Andrea, Alberto, Witek - Documentation: o Finalized online documentation for GRID validation. o Two new AA notes have been produced. They both deal with dedicated studies using the Simplified Calorimeter testing suite. The first describes the findings on the role of neutrons for the lateral hadronic shower profile: CERN-LCGAPP-2012-02 "Simplified Calorimeter: Investigations on the lateral profile simulation of hadronic shower shapes". The second describes the technical implementation of the "shower moments analysis" and contains instructions on how to extend it: CERN-LCGAPP-2012-01 "Simplified Calorimeter: shower moments". - Validation: o Validation of the last Geant4 9.6-beta release has been performed on the GRID, carried out using large resources at CEA, CERN, and KEK, and additional machines at LLR and Nikhef. Extensive testing was carried out to ensure the robustness and stability of results compared with the previous Geant4 versions. Great stability, no crashes observed. Slight differences in physics observables for FTFP_BERT are measured; the response is a little bit higher; the resolution is overall stable; shower widths are slightly narrower compared to release 9.5, especially for heavy absorbers; longitudinal shower is slightly shorter. Effects which are likely due to recent tunings to the FTF model for diffraction. --------------------------------------------------------------------- ==== Generator services - Witek - GENSER: o New generators installed: amcatnlo-1.0, evtgen-1.0.0, pythia6-426p12 vincia-1.0.28, herwig++-2.6.0, thepeg-1.8.0, pythia8-165, tauola++-1.0.7, photos++-3.5 - 2012 Planning Meeting: o The 2012 planning meeting took place on April 25th. The status of the project was presented by WP to the experiments and open questions were discussed. In general, the experiments are satisfied with the way the project is running and they are using the GENSER repository in all the productions. o Builds of generators with HepMC 2.03.11 is still needed by ATLAS. ATLAS agreed to set the milestone of definitely freezing its use by the end of 2012. After that date, no new versions of any generators will be build against HepMC 2.03.11 and therefore there will be no more the requirement for the generators code to compile against that version. Builds of generators with HepMC 2.06 series should follow the LCGCMT cycle. The version of HepMC in LCGCMT is the one actually used by the experiments. In addition to that, it was suggested to have builds with the latest version of HepMC, in order to allow testing. o MacOSX is actually not used by any of the experiments in production. There is no real need to have full GENSER on MacOSX. Therefore, it was decided to build only the main (new C++) generators on MacOSX, which come with the build systems working on this platform. o RPATH issues needs to be further discussed. --------------------------------------------------------------------- ==== Fluka - Alfredo - No report. --------------------------------------------------------------------- ==== Geant4 - John, Gabriele - Release 9.6-beta: o The 9.6-beta preview release of Geant4 has been prepared for release on 29th June. o Key non-physics developments in this release include: + Fixes to address issues which spoiled reproducibility when starting from an intermediate event. + Enabled checking of energy/momentum conservation for large errors: hadronic processes now trigger re-sampling of the interaction if the default limits for energy/momentum conservation are exceeded. A warning message is printed if this occurs. o Physics improvements include: + Improved description of diffraction cross-section and final state in FTF physics model. + New model of gamma-nuclear and electro-nuclear interactions. Gamma-nuclear reactions use the Bertini cascade; electro-nuclear process uses CHIPS total cross-sections and models, with the final state using the Bertini cascade and FTF model. Both are now in use with the FTFP_BERT physics list. + Adoption of Bertini model for nuclear capture at rest of pi-, K-, and Sigma-. They are used in the FTFP_BERT and FTFP_BERT_TRV physics lists. Also using combination of FTF and Pre-compound models for anti-proton and anti-Sigma+. + Using Shen and ion/proton cross-sections for ions, instead of Tripathi cross-sections. Improved cross-section for light ions including deuteron. + New total cross-section sets based on SAID data-base. + New classes extracted from the CHIPS package for cross-sections and models for elastic and inelastic reactions for protons, neutrons, pions, kaons, hyperons and anti-baryons. Hadronic interfaces are now located in the main hadronic module and can now be selected individually for use in physics lists. + The INCL cascade model (INCL++) is updated to version 5.1 and can now handle heavy-ion collisions. + New data set G4EMLOW-6.27 including Bremsstrahlung data files from NIST with extended grid, and probabilities of scattering off electrons from S.M.Seltzer and M.J.Berger 1986 paper. + New neutron data set G4NDL-4.1, converted from ENDF/B-VII.r1 for most isotopes. Isotopes of Cl, Be, Mn, As, Y, Zr, W, Th and Pa are unchanged. New independent and cumulative fission product yield data, obtained from ENDF/B-VII.r1. + Use of the WentzelVI model for multiple scattering of e+ and e- above 100 MeV in all physics lists for HEP applications. Improved angular distributions for large deflection angles at high energies. + Extended energy range of dEdx and other tables for monopoles with large mass, as required for the interpolation of dEdx for super-heavy monopoles. o Technical improvements include: + A description of each hadronic process; model or cross-section can now be printed in HTML by invoking the new Description() methods. + Removed obsolete methods Get/SetModel() from optical processes. This requires the suppression of such calls for those custom physics lists and physics configurations in which the optical boundary process is defined. + Adoption of a new version for the CLHEP library, CLHEP-2.1.2.3. + Fixed cases of variable shadowing. - Experiments/users feedback: o A performance degradation in Geant4 9.5 and 9.5.p01 for hadron simulation was reported by CMS. A fix is prepared and undergoing testing. - Manpower: o Students funded by the Google Summer of Code 2012 are working in the SFT group on two Geant4-related mini-projects. The first is working on profiling and seeking performance improvement by reordering execution. The second is working on a prototype of Geant4 on GPU, focusing on geometry navigation for realistic HEP setups. - Meetings & courses: o The 2012 Geant4 Collaboration meeting (17th of the series) will take place in Chartres (France) on 10-14th September. --------------------------------------------------------------------- ==== Garfield - Rob - Publications: o Paper on VUV (excimer) and gain in Xe mixtures (experimental and theoretical) showing excellent agreement. - Garfield: o Interface with an open source finite element program (Gmsh/Elmer) shown to be functional. o Collaboration established with Tadeusz Kowalski for gain curve measurement which should greatly help computing the Alice TPC GEMs amongst others. o CERN summer students are starting to arrive --------------------------------------------------------------------- ==== AOB Next meeting scheduled for September 25th.