Simulation Project Leaders Meeting 29-November-2011 ==== Attendees (virtual meeting) John Apostolakis (JA), Andrea Dotti (AD), Alfredo Ferrari (AF), Witold Pokorski (WP), Rob Veenhof (RV), Gabriele Cosmo (GC). --------------------------------------------------------------------- ==== Minutes --------------------------------------------------------------------- ==== Simulation physics validation & framework - Andrea - Meetings o The LPCC Detector Simulation Workshop was held at CERN on 6-7 October 2011. All LHC experiments contributed, together with simulation developers. The agenda is available at: http://indico.cern.ch/conferenceOtherViews.py?view=standard&confId=144956 The main conclusions of the workshop can be summarized as follows: - Very good agreement between collision data and Geant4 simulation. - Collisions allow to test additional primaries w.r.t. test-beam: in particular emerged need to improve simulation of kaons, anti-nucleons and (anti-)light ions. - Improvements of hadronic shower shapes (both lateral and longitudinal) is needed. - It is important to continue to guarantee stability of simulation both in terms of physics and software performance. - All experiments are focusing on a limited set of hadronic models for production (Precompound, Bertini, Fritiof). As a consequence improvements of these models be the main focus and priority for Geant4 developers. LCG Physics Validation Project specific: - Public results from collision data will be collected in website to serve as a repository for validation of detector simulations. - New format to project: topical meetings with detector experts on agreed aspects. Open Workshops (every 18-24 months) to publicly discuss results and update status of validation. - Activities o A new note describing validation of meson-induced target diffraction has been prepared: CERN-LCGAPP-2011-03. o The SimplifiedCalorimeter application has been moved to SVN repository. Scripts and files to allow production of data on distributed resources (including GRID), have been included. The application can be used as an example to extend a simulation code to run on the GRID o Recent activities have been focused on the validation of the upcoming Geant4 release 9.5. A report will be made available. --------------------------------------------------------------------- ==== Generator services - Witek - GENSER: o New generators installed/tested/validated: pythia6-426, pythia6-426.2, vincia-1.0.27, pythia8-157, herwig++-2.5.2, thepeg-1.7.2, pomwig-2.0a.2, pomwig-2.0a, hepmcanalysis-3.4.11.b, mctester-1.24.4.a, sherpa-1.3.1, sherpa-1.3.1.2, cteqpdf-1.0.4, hepmcanalysis-3.4.11. - MCPLOTS: o Added new feature allowing to filter the displayed graphs according to the selected Rivet analysis. - HepMC: o The HepMC meeting (where Lynn will report on proposed new features for the 2.07 series) has been postponed until the beginning of the next year on Lynn's request. --------------------------------------------------------------------- ==== Fluka - Alfredo - No report. --------------------------------------------------------------------- ==== Geant4 - John - Release 9.5: o The Geant4 release 9.5 scheduled for Friday, December 2nd is including many new features and fixes; to mention: * New model for Bremsstrahlung, "G4SeltzerBergerModel", based on the tabulated cross-sections published by S.M. Seltzer and M.J. Berger. It provides agreement with the low energy Livermore and Penelope models below 10 MeV and the standard relativistic model at 1 GeV, improving the most over the previous 'standard' Brehmstrahlung model in the energy range from 1 keV to 1 GeV. It is now used by default at energies below 1 GeV. * Extended interactions of antinucleons with matter in the Fritiof (FTF) model to stopped particles. * Revisions in the Binary cascade to improve the excitation energy for re-scattering. * Revision of interface to hadronic cross-sections allowing consistently integrate new development for low-energy neutron transport and improved hadron cross-sections for high energy. * Addition of new pi- absorption at rest process using the Bertini/Precompound model and separation of the quasi-elastic process from the CHIPS code. * Revision of physics-list interface allowing reduction in two times number of reference physics-lists but enabling more options for electromagnetic and ion physics including DPMJET-II.5 interface. * Extended validation for electromagnetic and hadronic physics. * New base-material approach allowing reuse of physics table build for one material by a group of similar materials with different densities. * Added biasing options built in electromagnetic physics. * Possibility to define volumes with material in parallel geometry layers; volumes created can complement or overlap the standard 'main' geometry for tracking. Enhancement of the existing functionality for parallel specialised geometries, which is also used for scoring, fast simulation, shower parameterisation and event biasing. * New G4CutTubs solid, a tube with possible cuts in +-Z. * Fully functional installation system based on CMake. o Among the included fixes, to mention: o Corrected issue of charged tracks stuck on boundaries reported by ATLAS; by improving the criterion for intersecting volume boundaries and the provision of surface normals by the navigator. o Fix in the Binary Cascade for a large energy non-conservation observed for hydrogen targets. o Contributions from external groups include: o Interface of Bertini cascade to the pre-compound and de-excitation module, enabling improved generation of low energy secondaries. In addition a new interface is provided to handle the re-scattering of fragments from the high energy string models. Bug fixes in the three-body final state reactions provided slightly better angular distributions of final state hadrons. Reduced memory churn (allocation and de-allocation of memory) significantly throughout the implementation of Bertini. o The first version of INCL++, fully re-engineered in C++ and based on the INCL4.6 model. It supports proton, neutron and pion projectiles up to 3 GeV and uses the Geant4 nuclear de-excitation after the cascade. o A new fast Rayleigh scattering model for the Geant4 standard EM. o The recent TOTEM measurements were used to improve hadron-nucleus and nucleus-nucleus cross-sections at high energies. o Improved Geant4 fast Glauber model for total, inelastic and elastic kaon-nucleus cross-sections. o Fast and roboust angular model for Geant4 relativistic EM processes. --------------------------------------------------------------------- ==== Garfield - Rob - No report --------------------------------------------------------------------- ==== AOB Next meeting scheduled for February 21st.