Validation of GEANT4 by the CMS Experiment ARCE Pedro 1,2, ARCELLI Silvia 3, BANERJEE Sunanda 4, BANERJEE Sudeshna 4, BOCCALI Tommaso 5, DE LA CRUZ Begoña 1, DE ROECK Albert 2, DUTTA Suchandra 5, ELVIRA Daniel 6, FANFANI Alessandra 3, INOCENTE Vincenzo 2, JOSÁ Isabel 1, LASSILA-PERINI Kati 7, LIENDL Martin 2,8, MAZUMDAR Kajari 2,4, NEUMEISTER Norbert 8, NIKINTENKO Alexandre 9, RIZZI Andrea 10, SILVESTRIS Lucia 5, STAVRIANAKOU Maya 2, STRAESSNER Arno 2, WELLISCH Hans-Peter 2, WYNHOFF Stephan 11, ZYCH Pawel 12 1 (CIEMAT, Madrid, Spain), 2( CERN, Geneva, Switzerland), 3 (INFN Padova, Italy), 3 (Tata Institute, Bombay, India), 5 (INFN Bari, Italy), 6 (Fermilab, Chicago, USA), 7 (HIP, Helsinki, Finland), 8( HEPHY, Vienna, Austria), 9 (Imperial College, UK), 10 (SNS, Pisa, Italy), 11 (Univ. Princeton, USA), 12 (IEP. Warsaw, Poland) (for the CMS Collaboration) CHEP 03, La Jolla, 24th March 2003 CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 1
Index Status of GEANT4 simulation (OSCAR) Geometry checks Physics checks EM calorimeter Muon physics Hadronic calorimeter Release testing CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 2
Geometry: GEANT4 Simulation (OSCAR) All CMS detectors Also several Testbeams Geometry described in XML Common to Simulation/Reconstruction/Visualisation All geometry converted from GEANT3 geometry -> XML Detailed checking in progress Magnetic field: 3D magnetic field implemented Review in progress to speed up its access CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 3
Sliced view of CMS barrel detectors View of CMS muon system View of CMS pixel detector CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 4
Primary generator: OSCAR status (II) CMS particle gun: Scan in θ, η, energy Random (flat/gaussian) in θ, η, energy Interface with PYTHIA ntuples and HEPEVT ASCII files Interface with Interface with HEPEVT and HepMC UserActions: Several user actions of the same type loadable on demand Using COBRA Dispatcher-Observer pattern Persistency: Hits for all detectors Primary generator particles Selected tracks Use CMS framework (COBRA) Use ROOT IO CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 5
Physics: OSCAR status (III) Electromagnetic processes needed at LHC Hadronic processes needed at LHC CMS Physics Technical Design Report is planned to be written using OSCAR (due end 2005) OSCAR milestone June 2003: Reproduce the physics results of the GEANT3 simulation with similar performance Physics Cuts: Production cuts per material Minimum kinetic energy cuts per material Still under investigation if we really need them Other User Limits: Max. time of flight, Min. range, Max. step length, Max. track length CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 6
OSCAR - IGUANA Interactive visualisation is done with IGUANA Visualise any GEANT4 Geometry Select by logical volumes / by physical volumes Picking, slices Volume property window GEANT4 command line A wizard to guide through OSCAR settings Adding other extensions is trivial (e.g. GUIs like overlap detection) Visualise Tracks Visualise magnetic field Integrated with overlap detection Find overlaps, show result details in a list Highlight overlaps in 3D Hits, in the near future CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 7
OSCAR - IGUANA Overlap detection Example extension (a trivial wizard) Queried from plug-in database, loaded on request and bound to IGUANA G4 Run Manager Control of arbitrary GEANT4 tree Correlated Picking IGUANA viewer displaying OpenInventor scene CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 8
OSCAR - IGUANA: magnetic field 2D plane that can be rotated Field direction as an arrow Field intensity as colour CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 9
Framework: OSCAR status (IV) COBRA: Common generator interface for Simulation and Reconstruction COBRA/Mantis: interface with GEANT4 (see talk at this conference - Maya Stavrianakou) Production tools: Integrated with CMS production tools (see talk at this conference - Veronique Lefebure) OSCAR is ready for physics validation studies Detailed checks have to be done to allow the Data Challenge 04 production, starting july 2003: Handle the amount of data produced in one month at 5% = 50M events CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 10
Geometry debugging GEANT3 files in ZEBRA RZ format has been automatically converted to XML for simulation and reconstruction GEANT3 has always been the source of the geometry for simulation and reconstruction Detailed checks have been done to assure that the geometry is the same Check that you have the same objects(materials, solids, volumes, touchables) Check that touchable centres in global co-ordinates correspond to the same touchables in GEANT4 geometry Material budget Compare step by step if needed Still we have to hunt for overlaps ( MANY is not allowed in GEANT4) Use CMS overlap detection tool (already integrated in GEANT4) (see talk at CHEP 01 - Martin Liendl) CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 11
Checking physics: De/Dx in Silicon Detector CMSIM 125 and ORCA_6_3_0 OSCAR_2_1_1 (geant4.5.0 / CMSIM 127 Geometry) and ORCA_7_1_1 Particle Types: Muon, Pion, Kaon and Electron Momenta: 2, 3, 4, 5 and 10 GeV Eta : 0.8 FED Dynamic Range : 12 bit Secondary Particle Generation : 1 MeV cut off in the Sensitive Material (optimized with PHOBOS/ALEPH Data) Very high cutoff in Insensitive Material (LOSS 2) for CMSIM 125 10cm cutoff for OSCAR CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 12
Energy Loss by 5 GeV Muon Checking physics: De/Dx in Silicon Detector CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 13
de/dx vs Momentum Checking physics: De/Dx in Silicon Detector CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 14
SETUP: Checking physics: EM calorimeter CMS electromagnetic calorimeter: lead tungstate crystals pointing to interaction point Photon of E = 30 GeV enters front face of crystal No magnetic field What was compared: E in hottest crystal, in 3x3, in 5x5 matrix E total dn hits /dt, for 1 ns time slices GEANT3.21 vs GEANT4.4.0.p02 CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 15
CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 16
CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 17
CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 18
Bremsstrahlung 10 GeV 100 GeV 1000 GeV CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 19
Pair Production 10 GeV e+eproduction 100 GeV 1000 GeV CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 20
Multiple scattering 10 GeV LEP I Z µµ events in L3 detector 100 GeV 1000 GeV CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 21
Checking Physics: EM calor. + Hadr. calor. testbeam 1996 Testbeam Setup for CMS HCAL A test module of copper absorber plates with scintillator tile sampling 28 scintillator plates with absorber of varying thickness in between A prototype lead tungstate crystal electromagnetic calorimeter Energies: 225 GeV µ (for calibration), 10-300 GeV π, 10-300 GeV e- Magnetic Field: 0, 0.75, 1.5, 3 tesla (direction parallel to the face of the scintillator) Configuration: Only HCAL or ECAL + HCAL 5000 events were taken for each setup Response of the Calorimeter was studied as a function of: Magnetic field: effect on scintillator Absorber thickness: optimisation of resolution versus containment Absorber depth: energy containment Electromagnetic Calorimeter contribution: e/π effects CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 22
Checking Physics: EM calor. + Hadr. calor. testbeam GEANT4 4.0.p02 100 GeV pi+ 0 Tesla ECAL+HCAL CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 23
Checking Physics: EM calor. + Hadr. calor. testbeam 100 GeV e- 0 Tesla HCAL CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 24
Checking Physics: EM calor. + Hadr. calor. testbeam Events with MIP in ECAL pi+ 0 Tesla ECAL+HCAL Events with shower in ECAL CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 25
Checking Physics: EM calor. + Hadr. calor. testbeam pi+ 0 Tesla Events with MIP in ECAL ECAL+HCAL Events with shower in ECAL CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 26
Release testing The quality of each release should be checked before making it public Also each production centre has to test the release quality after installation Not only that it compiles and runs, but also that differences on results are understood Tool must be easy to use and allow to compare results automatically, without help from expert A tool has been developed a tool for regression testing in CMS: OVAL See talk in this conference - David Chamont For physics we cannot do but an statistical testing of some distributions We are investigating the use of the GEANT4 statistical testing suite (see talk at this conference M. Grazia Pia) CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 27
Current release testing in OSCAR Geometry Test the number of objects constructed [OVAL] Number of G4VSolid's: 3190 [OVAL] Number of G4LogicalVolume's: 3190 [OVAL] Number of G4VPhysicalVolume's: 18988 [OVAL] Number of Touchable's: 1171167 [OVAL] Number of G4Material's: 341 Send 1000 tracks randomly distributed in eta and phi and check material budget [OVAL] MaterialBudget 0-3.52742 112.678 335.693 Magnetic field propagation Send charged geantinos of energies 1, 10, 100, 1000 GeV Check end point position w.r.t. straight line prediction [OVAL] DEVIATION: 0-575.577 708.6 Check change in kinetic energy and deviation in direction [OVAL] MOMENTUM: 0 2.11234e-07-0.0276428 0.021342 CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 28
Current release testing in OSCAR Hits Test that the same hits are stored in DB at the same positions [OVAL] TrkMuon Hit: MBarrel #hit 5 ID 1644952 [OVAL] TrkMuon Hit: MBarrel globalr3 438.533 [OVAL] TrkMuon Hit: MBarrel globaleta 0.0435001 [OVAL] TrkMuon Hit: MBarrel globalphi 0.0436332 [OVAL] TrkMuon Hit: MBarrel TOF 14.65 [OVAL] TrkMuon Hit: MBarrel PABS 98.0501 [OVAL] TrkMuon Hit: MBarrel entryptx 19.2179 [OVAL] TrkMuon Hit: MBarrel entrypty 20.2891 [OVAL] TrkMuon Hit: MBarrel entryptz -6.57598 [OVAL] TrkMuon Hit: MBarrel exitptx 19.1677 [OVAL] TrkMuon Hit: MBarrel exitpty 20.3392 [OVAL] TrkMuon Hit: MBarrel exitptz -7.72598 CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 29
Current release testing in OSCAR Physics First test: check energy deposition and shower shape in calorimeter Not yet OVALised. Investigating GEANT4 validation tool Other tests in progress Generator particles (tracking by GEANT4 and DB checking) Persistent tracks Monitor performance More comprehensive physics tests CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 30
Summary CMS GEANT4 simulation is ready for detailed physics comparison Data Chalenge 04 (50M events) starts July 03 OSCAR physics has to be validated in detail First physics tests show GEANT4 is as good or better as GEANT3 OSCAR performance has to be similar to GEANT3 simulation A comprehensive suite of OVAL tests is being built to assure the quality of each release CHEP 03 GEANT4 Validation by CMS Pedro Arce(CIEMAT/CERN) 31