1. Simulation Project Status LHCC Comprehensive Review 2006 Gabriele Cosmo, PH/SFT

2. 25/09/06LCG Simulation Project Status - G.Cosmo2 Simulation sub-projects  Simulation framework –Interface to multiple simulation engines (Geant4, Fluka) and geometry models exchange (GDML), MC truth handling, Python interfaces  Geant4 team participating –Aligned with and responding to needs from LHC experiments, physics validation, simulation framework  Fluka team participating –Framework integration, physics validation  Garfield team participating –Garfield package integration and support in LCG - SPI  Simulation physics validation –Assess adequacy of simulation and physics environment for LHC and provide the feedback to drive needed improvements  Generator services –Generator libraries; validation/test suite; development when needed (HepMC, etc.); common event files Witold Pokorski John Apostolakis Alfredo Ferrari Alberto Ribon Witold Pokorski as of 15-Sep-06 Rob Veenhof

3. 25/09/06LCG Simulation Project Status - G.Cosmo3 Project Organization Simulation Project Leader Framework WP Geant4 WP Fluka WP Physics Validation WP Generator Services WP Subprojects Work packages Geant4 Project Fluka Project Experiment Validation MC4LHC Garfield WP

4. 25/09/06LCG Simulation Project Status - G.Cosmo4 Recent developments … For details, see presentations at recent AA Internal Review: http://agenda.cern.ch/fullAgenda.php?ida=a063165

5. 25/09/06LCG Simulation Project Status - G.Cosmo5 Geant4 - 8.0 (January release), developments 1. New capabilities zEM (‘standard’) : new MSC model implementation zNew design for particle definitions, no longer ‘static’ zRevised fast-parameterisation: usage of ‘regions’ zGeometry overlap check at construction 2. Improvements and fixes zto existing hadronic physics modeling & models zStrong interaction and collaboration with Physics Validation project zin physics process implementations zextending functionality that existed zin good part result of user feedback and requirements 3. Migrations, updates zSupport for CLHEP 2.0.X series zKeeping compatibility with 1.9.X series

6. 25/09/06LCG Simulation Project Status - G.Cosmo6 Geant4 - 8.1 (June release), developments 1. Adoption of a new Geant4 Software License (and CA) zBased on EGEE model: http://cern.ch/geant4/license/http://cern.ch/geant4/license/ 2. New capabilities zUpdated particle definitions to match PDG-2005 zNew ‘material scanner’ utility zNew ‘tessellated’ solids for interface with CAD systems zß-release of very low-energy DNA processes in water 3. Numerous improvements in EM “standard” physics zSimulation of back-scattering improved zImproved stability of EM energy deposition, resolution zFrom revision of electron transport (Multiple Scattering) zEnables better accuracy at higher cuts - with less CPU zVisible energy in sampling calorimeters less sensitive to production threshold 3. Fixes in hadronic physics and reviewed physics-lists zNew combined elastic-scattering models zExtended use of Binary and Bertini cascade models zStrong interaction and collaboration with Physics Validation project

7. 25/09/06LCG Simulation Project Status - G.Cosmo7 Geant4 - Robustness, testing  Low rate of problems in production –Was <~ 10 -4 per LHC event with Geant4 release 5.x –CMS reports 10 -6 per event (G4-related) with Geant4 release 6.2  New, large-scale, regressions testing –Finds rare problems –Used LCG/EGEE Grid »Need and got > 150 CPU-weeks in 10 days »Geant4 VO  thanks to LCG team, CERN, Imperial C., Nikhef, CIEMAT –Identifies physics revisions, finds new software issues »For details, see A. Ribon ’ s talks at CHEP 2006, AA meeting

8. 25/09/06LCG Simulation Project Status - G.Cosmo8 Fluka - Major steps since mid 2005  May 2005 : definition and approval of the FLUKA license  July 2005 : release of FLUKA 2005.6 –release of the FLUKA source code for INFN and CERN researchers  October 2005 : Publication of the FLUKA description and user guide as a CERN yellow report ( CERN-2005-010)  September 2006 : Release of FLUKA 2006.3 –release of the FLUKA source code to all scientific institutions

9. 25/09/06LCG Simulation Project Status - G.Cosmo9 Fluka - New Release: 2006.3 Major new features: (see release notes for details)  Input by names  Generation of primary ionisation events (request by ALICE)  New high-energy hadronic generator (available as option, will become the default)  Improvements in the evaporation/fission models  First implementation of photon-muon pair production (mu- pair).  An initial implementation of the BME model for low energy nucleus-nucleus interactions (available on request)  Activity concentration 2D/3D binnings (was only by region)

10. 25/09/06LCG Simulation Project Status - G.Cosmo10 Garfield - Developments  Completion of the interface with QuickField  Reproducibility of random number sequences ensured; Heed random number generator replaced to ensure independence of long runs  Development of BEM (Boundary Element Methods) as an alternative to field calculations using analytic methods and finite element methods (FEM)  Use of BOINC for generation of transport tables for wide selection of gases and wide range of magnetic field configurations –Usage of the GRID envisaged  Porting on MacOS X

11. 25/09/06LCG Simulation Project Status - G.Cosmo11 Physics Validation  Background radiation studies –Goal: comparison of Fluka and Geant4 predictions »Geant4 now offering a precise treatment of low energy neutrons with some Physics Lists like QGSP_BERT_HP –Radiation studies in LHCb, CMS –TARC benchmark test »new benchmark for neutrons. Validates spallation neutron production for GeV protons on pure lead, and neutron transportation down to thermal energies  Simple benchmarks –inclusive π± production in π±,K+,p,p interactions on Mg, Ag, Au, at 100 and 320 (π-) GeV/c – results ready!  Test beam setups –ATLAS EM barrel test beam 2002 –CMS HCAL test beam 2004 –ATLAS HEC test beam (Geant4 release validation) –ATLAS barrel combined test beam 2004 –ATLAS TileCal test beam 2002 »First comparison with Fluka using GDML and simulation framework TARC neutron benchmark LHCb cavern

12. 25/09/06LCG Simulation Project Status - G.Cosmo12 Physics Validation -2  Investigations in various directions are undergoing in strict collaboration with Geant4 experts to understand and improve hadronic shower shapes in the simulation –Cross-sections (elastic and inelastic) –Model of the hadronic elastic scattering –Neutron production –Production (multiplicities), rapidity and spectra in hadron-nucleus collisions –Diffraction  Test bench prototype for ATLAS test beam 2002 LAr data –Correct the data, as it is done for cross-sections measurements –Allows Geant4 and Fluka developers to use directly the calorimeter test- beam data for validation purposes  Relation between simulation developers and experiments has improved, and it is now very good!  Progress has been slower than expected –Complexity of the setups –Detailed description of instrumental effects –Other commitments of people in the experiments …

13. 25/09/06LCG Simulation Project Status - G.Cosmo13 Generator Services - 1  New Project leader: Witold Pokorski (PH/SFT) replacing P.Bartalini  GENSER –New release last summer: 1.4.0 »Quarterly official releases (2 nd digit incremented) »~3 weekly pre-releases before official releases (access to beta-testers) »Bug fix releases (3 rd digit incremented)  Further special releases arranged under request –New requests from LHC experiments (new generators, new versions of existing generators, etc.) »Collected in LCG Generator monthly meetings –Modular packaging (since release 1.2.0) –First release of Herwig++ in hadron colliders expected soon –Migration from g77 to g95 and gfortran almost complete –Widely used by three LHC experiments: satisfaction expressed –Some critics expressed by MC authors in recent MC4LHC workshop in July »Procedural mistakes in releasing and fixing bugs »Packaging issues for some MC generators »More testing needed for core generators »Control of feedback and support requests from experiments

14. 25/09/06LCG Simulation Project Status - G.Cosmo14 Generator Services - 2  Pythia 8 –T.Sjostrand working full time at CERN PH/SFT as research associate –A fresh start, stand-alone C++, with 3 year road-map, Sep 2004 - Sep 2007 –Latest development version included in GENSER 1.4.0 – User’s feedback is welcome!  MCDB (MC event Data Base) –Ready to use ! - http://mcdb.cern.chhttp://mcdb.cern.ch –Features: Web interface; database; search engine; CASTOR as native storage; Grid compatible. Event files in HepML as unified XML format –CMS migrating to the new service. Little interest for now from ATLAS  Generators framework –General interface to any generator provided by GENSER. Production & Validation –Based on: GENSER, HepMC, Root/Pool –Developed and maintained in CMS; CMS production based on it –Production framework is ready, Validation framework is in progress

15. 25/09/06LCG Simulation Project Status - G.Cosmo15 Simulation Framework - 1  GDML (Geometry Description Markup Language) –Extended to support all solids / constructs of Geant4 –Added support for optical surfaces and material properties –Root binding: reader and writer integrated in Root –Geant4 binding: »Support for modular GDML geometries »Included converter CAD(STEP) to GDML ST - Viewer An interactive tool for viewing 3D CAD information STEP files ST – Viewer uses an internal file format (.geom &.tree) to store geometry info STEPGDML Library functions created to convert STEP into GDML files GDML Output File Equivalent to the original STEP file Contains only tessellated solids

16. 25/09/06LCG Simulation Project Status - G.Cosmo16 Simulation Framework - 2  FLUGG –Extended detector construction to allow loading of GDML geometry files –Implemented manager of hits to mimic Geant4 behavior for the “sensitive detectors” –Added Root I/O persistency for hits –Exercised with ATLAS TileCal test beam 2002 setup  Python interfaces –Reflex/PyROOT, Python binding for Geant4  Geometry object persistency –Extensions to Geant4 and Root to allow Root I/O binary persistency  MC truth handling –Implemented example 'MCTruthManager‘ –Using HepMC as the event record format

17. 25/09/06LCG Simulation Project Status - G.Cosmo17 Simulation Project major Milestones : 2005-2007  2005/02: VD502 - Review/prioritization os simple benchmarks for physics validation  2005/05: VD508 - First results of background radiation studies in Geant4  2005/06: VD512 - New validation results on longitudinal shower shapes in Geant4  2005/06: SF515 - GDML schema extension to support divisions and reflections  2005/06: SF516 - Feasibility study of Pool/Root-based geometry persistency in Geant4  2005/06: SF517 - Python implementation of GDML writers for Geant4 and Root  2005/06: G4518 - Geant4 7.1 public release  2005/07: G4519 - Tutorial on Geant4 at CERN and move of Geant4 code repository to IT service  2005/09: VD522 - 3 rd simple benchmark completed  2005/09: VD524 - Validation of Fluka against ATLAS TileCal test-beam  2005/09: GS527 - Procedure for light GENSER releases  2005/09: SF530 - Flugg application to ATLAS TileCal test-beam simulation  2005/10: G4531 - Improved Geant4 regression suite for release validation and testing infrastructure  2005/10: VD532 - First results of ATLAS combined and 2004 test-beams data comparisons  2005/12: GS535 - Generator level production framework: production quality release  2005/12: GS536 - Evaluation of possible migration of HepMC to LCG  2005/12: SF537 - Introduction of modularization of GDML files  2005/12: SF538 - Proposal for universal handling of Monte Carlo truth  2005/12: GF540 - Interface in Garfield with new version of Magboltz  2005/12: GF541 - Interface in Garfield with new version of Heed  2005/12: G4542 - Geant4 8.0 public release  2006/03: GS602 - Introduction of MCDB GRID certificates and management of large files  2006/05: G4606 - Developments for Geant4 8.1 public release  2006/06: SF608 - Refinements to GDML schema to support user extensions of elements  2006/06: VD617 - Investigation of corrections to test-beam data for validation of stand-alone simulation engines  2006/12: G4618 - Report on the main physics effects responsible for hadronic shower development in Geant4  2007/06: VD703 - Application of corrections to test-beam data to the LHC calorimeter test-beam simulations  2007/06: GS701 - Generator level validation framework production version  2007/09: GS702 - Pythia 8 production release

18. 25/09/06LCG Simulation Project Status - G.Cosmo18 Current LCG simulation manpower Simulation framework1.80 (1.40) Geant47.20 Infrastructure, performance, management (approx)2.05 EM / Hadronic physics effort (approx)3.90 Tracking, biasing, geometry (approx)1.25 CERN staff (3.80), CERN fellows/associates (3.40) Physics validation2.30 Validation specific to experiments 1.50 Generator services3.30 (3.50) management, documentation/release (LCG CERN, Florida Univ.) 1.20 GENSER dev., Validation, MCDB (LCG Russia, Italy) 1.85 Production Framework (LCG Spain) 0.25 Fluka0.00 Garfield1.00 (0.20) Management0.25 Total 15.85 As of Sep 20