ATLAS Simulation/Reconstruction Software

1. ATLAS Simulation/Reconstruction Software James Shank DOE/NSF Review of U.S. ATLAS and CMS Computing Projects Brookhaven National Laboratory NOVEMBER 14-17, 2000

2. Outline • Requirements • Get simulation/reconstruction ready in time for Mock Data Challenges • Technical Choices • Object-oriented design, C++ implementation. • Organization (US and international ATLAS) • Current/near-term future work • Resource Requirements • Some computing professional help is crucial • Schedule • OO reconstruction release end of this year, then on to MDC. J. Shank ATLAS Simulation/Recon. SW.

3. ATLAS Detector/Task matrix From N. McCubbin’s talk Physics Coordinator: F.Gianotti Chief Architect: D.Quarrie J. Shank ATLAS Simulation/Recon. SW.

4. Subdetector Software • Brief survey of subdetector software recent activities and near-term plans • Silicon Tracker • Transition Radiation Tracker (TRT) • Liquid Argon Calorimeter • Tile Calorimeter • Muon Spectrometer • Goal: Combine strong core and subsystem software roles to closely couple core development to real-world testbeds and applications • Recognized in ATLAS as very important • Enable physicists to contribute to software development J. Shank ATLAS Simulation/Recon. SW.

5. Subdetector Current/Near-Term SW Activities • Performance/design studies – All • G3 based simu – All • Test beam – Si, LAr, Tile • Athena integration – Si, LAr, Tile, Muon • Reconstruction development in C++ - Si, LAr, Tile, Muon • G4 based simu dev – Si, TRT, LAr, Muon • G4 physics validation – Si, LAr • XML based det description – TRT, Tile, Muon • Database – LAr, Tile, Muon • Trigger/DAQ J. Shank ATLAS Simulation/Recon. SW.

6. Silicon Tracker (L. Vacavant/LBNL et al) • Integration of Kalman based reconstruction in Athena underway (with I. Gavralenko) • Geometry and digits redesigned and interfaced; • output classes defined • Will be useful for all ID tracking packages • tested on single tracks • Starting now: • code is in the ATLAS repository; • tests on full events; • design iteration (modularity) • Pixel test beam simulation in Geant4 • Digi chain redesigned for modularity and implemented in G4 • Now starting: G4 physics validation against G3 and test beam • Tracking performance: studies of FE electronics performance impact ongoing J. Shank ATLAS Simulation/Recon. SW.

7. TRT (F. Luehring/Indiana et al) • F. Luehring: TRT SW coordination, Inner Detector (ID) simu coordination, ID Geant material coordination, ARC… • TRT Geant3 simulation maintenance • Rate studies of beam pipe designs led to all-Be design selection (Geant3) • Participating in G4 barrel geometry development • Near term: • Updated TRT signal shapes into G3 digitization • TRT detector description in XML • TRT digitization into Geant4 (K. Assamagan/Hampton, F. Luehring/Indiana) J. Shank ATLAS Simulation/Recon. SW.

8. Tuning G4 Energy Smearing in TRT K. Assamagan J. Shank ATLAS Simulation/Recon. SW.

9. TRT PAI Comparison to Data K. Assamagan J. Shank ATLAS Simulation/Recon. SW.

10. LAr Simulation (M. Leltchouk/Nevis et al) • LAr simulation coordination: M. Leltchouk/Nevis • Participation in G4 EM barrel development • Major int’l effort, now in test beam/G3 comparisons • Coordination of HEC into G4 (w/Montreal, Munich) • FCAL test beam, G3, G4 comparison studies (P.Loch Arizona, R. Mazini Montreal) • Near term: • LAr offline data class design (BNL, Nevis, Int’l) • Geant4 integration into ATLAS • Geant4-ATLAS test beam comparison project • Long way to go on G4 physics validation J. Shank ATLAS Simulation/Recon. SW.

11. LAr Reconstruction (S. Rajagopalan/BNL et al) • LAr reconstruction coordination: S. Rajagopalan/BNL just appointed • OO LAr reconstruction development (H.Ma, S.Rajagopalan/BNL, J.Schwindling, M.Weilers) • Released 4/2000, most Atrecon features preserved • Very good agreement with Fortran Atrecon results, event level, barrel and endcap • Athena integration 4-5/2000 • First major application integrated in new framework; basis for tutorial, A Team feedback • HEC reconstruction being incorporated • Near term: • FCAL reconstruction • Application in LAr EM test beam analysis • Integration with Tile Calorimeter reconstruction J. Shank ATLAS Simulation/Recon. SW.

12. GEANT 4 M. Leltchouk A 50 GeV e- in the EM Barrel Calorimeter K. Kordas “GEANT4 for the ATLAS EM calo” CALOR2000, Annecy, 12 October, 2000. J. Shank ATLAS Simulation/Recon. SW.

13. FCAL G3-G4-Testbeam comparisons Talk of R. Mazini/ P. Loch at CALOR2000 40 GeV electron signals J. Shank ATLAS Simulation/Recon. SW.

14. FCAL G3-G4-Testbeam comparisons Talk of R. Mazini/ P. Loch at CALOR2000 Cell signals for electron events J. Shank ATLAS Simulation/Recon. SW.

15. Tile Calorimeter (T. LeCompte, A. Gupta) • Tile Calorimeter DB coordination: T. LeCompte/ANL • Tile Cal reconstruction coord: F. Merritt/Chicago • C++ based test beam software ‘Pilot’ now has all functionality of old Fortran Tilemon • Optimal Filtering (correcting pulse height for phase of signal relative to beam) implemented • C++ based reconstruction in development; G3 digit information being used • First jet finding algorithm in use • Near term: • Pilot into Athena framework • Tile test beam data into Objectivity & Athena • Pursuing a common C++ high level class design with LAr J. Shank ATLAS Simulation/Recon. SW.

16. Test with ATRECON A. Gupta Atrecon (FORTRAN) TileRec (C++) J. Shank ATLAS Simulation/Recon. SW.

17. Tile Test Beam A. Gupta • Comparison of old FORTRAN with new C++ Fortran C++ J. Shank ATLAS Simulation/Recon. SW.

18. Tile Cal. Optimal Filtering A. Gupta • Determine shape of pulse in each PMT • Fit each waveform J. Shank ATLAS Simulation/Recon. SW.

19. Muon Spectrometer • Boston U (J.Shank), U Michigan, Harvard, BNL • Current activity: • Muon database and detector description • Muon DB coordination: S. Goldfarb/UM • Digit decoding into ATLAS Event from G3 complete -- except for CSCs • Detector element Identifiers implemented • XML detector description: MDTs, RPCs, TGCs implemented; full chain to Geant4 implemented • Geometry ID scheme for all subsystems defined and documented • OO muon reconstruction (Moore) development • New program based on components of 1st generation OO reconstruction program, AMBER. • Integrated into Athena; in repository; in early development • Muon L2 trigger simulation studies, code support • Simulation for detector layout optimization • Near term: • Completion of cathode strip chamber software • Trigger TDR studies: L1->L2 rejection, efficiencies • Calibration DB, trigger DB, ongoing detector description work J. Shank ATLAS Simulation/Recon. SW.

20. Offline Muon Reconstruction • Muon Object Oriented Reconstruction (Moore). • Bottom-up re-design and implementation of Muon track reconstruction. Diagram from Patrick Hendrik’s thesis J. Shank ATLAS Simulation/Recon. SW.

21. Moore XML Graphics MDT’s RPC’s J. Shank ATLAS Simulation/Recon. SW.

22. Moore XML Graphics J. Shank ATLAS Simulation/Recon. SW.

23. Moore to-do list • Fitting • Incorporate new OO version of old GEANE track fitting routine, COBRA • Interface to fitting procedure used in inner detector, iPatRec. • Graphics • Make Moore created objects, track segments, roads, etc., “plottable” in the ATLAS Athena sense. • Combined fitting using inner detector+calorimeter. • Performance tuning/comparisons with FORTRAN version J. Shank ATLAS Simulation/Recon. SW.

24. Trigger/DAQ Offline Software J. Shank ATLAS Simulation/Recon. SW.

25. TDAQ Offline Software/2 J. Shank ATLAS Simulation/Recon. SW.

26. TDAQ Software and Event Rates J. Shank ATLAS Simulation/Recon. SW.

27. Summary • New ATLAS framework, Athena, enthusiastically embraced by broad spectrum of sub-system community. • Many US physicists active in C++ code development • Well integrated into overall ATLAS software effort • Need OO/C++ expert to help with interface between subsystems and the control/framework/db software. • Part of NSF request for FY01 • Resident at CERN • Schedule: • OO recon for all subsystems available 12/00 • Probably will be a little late, some FORTRAN wrapping. • MDC 0 12/01 • Should have full OO sw ready, especially with help of IT professional J. Shank ATLAS Simulation/Recon. SW.