1. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 1 The CMS Simulation Validation Suite V. Daniel Elvira (Fermilab) for the CMS Collaboration

2. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 2 Simulation Software in CMS Detector Simulation GenerationDigitization Pool HepMC data file Pool SimHit data file Pool Digi data file Reconstruction Generation – MC truth information from particle gun or physics generator about vertices and particles. Stored in HepMC format. Detector Simulation – Hit objects with timing, position, energy loss information. Based on the Geant4 tool kit. Digitization – Constructs Digi objects which include realistic modeling of electronic signal. Digi objects. Reconstruction – Physics Objects: vertices, photons, e, , jets,……

3. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 3 Physics Software Validation Elements to validate: Geometry description & magnetic field map Physics of EM and Had showers in Geant4 - hits Digitization Model - digis Reconstruction Algorithms – physics objects For absolute validation: Use visualization tools, TB experiments, reference plots The Simulation Validation Suite (SVS) validates in an automated way each new release of the CMS simulation software, comparing values of quantities related to geometry, field, hits with reference values from a previously (absolutely) validated version. Expansion to “Physics Software Validation Suite” including digis, reco ……in progress

4. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 4 CMS Detector Systems 22 m long & 15 m in diameter Solenoid Magnet: 4 Tesla Field Electromagnetic Calorimeter (Ecal) Hadronic Calorimeter (Hcal) Silicon Tracker Muon System More than 1 Million Geometrical volumes SVS modular structure follows the detector sub-systems

5. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 5 SVS: General Description SVS software sub-systems (dedicated simulation packages) Pre-generated samples: single particles, pp physics (Pool files, ROOT browsable, HepMC format) OVAL: testing tool created by CMS to detect changes in software behavior. Used as the SVS integration tool. It executes scripts and shell commands to control the suite execution and perform comparison tests. SimG4TrackerValidation SimG4EcalValidation SimG4HcalValidation SimG4MuonValidation SimG4GeomValidation SimG4FieldValidation SimG4GlobalValidation Validation branch (Pool files, ROOT browsable) On the fly analysis: basic G4 objects processed into information to construct validation quantities. OVAL Configuration file: commands, tolerance values

6. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 6 SVS: General Description (II) ROOT Analysis Macros Construct Validation Quantities Create/fill histograms Read reference files Perform Validation Tests:   or Kolmogorov-Smirnov Validation branch (Pool files, ROOT browsable) One or more tests per sub-detector: low/high level quantities, different sub-detector components. Reference Histograms from previous version (ROOT file) List of differences for quantities not passing the tests (ASCII files) OVAL Configuration file: commands, tolerance values Results are reviewed by system experts: approve & release, or investigate problems (LCG PI Statistics Testing toolkit, or ROOT)

7. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 7 Tracker Validation Tracking system: Silicon Strip Tracker - Tracker Inner Barrel (TIB), Tracker Outer Barrel (TOB), Tracker Inner Disks (TID) and Tracker End Cap (TEC) Pixel Detector - Pixel Barrel and Pixel End Cap. Validation Quantities: Energy deposition Distribution of track entry and exit points Number of hits Time of flight,……, etc Sample: Single muons, electrons or pions with p T =15 GeV in 12 bins of in the range 3<  <3 (1,500 events) Reference Distribution Current Distribution Identical Distributions

8. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 8 Ecal Validation Electromagnetic Calorimeters: Ecal Barrel – Ecal Endcap (crystals) Preshower (Si/lead)  vs  hit occupancy in crystals E1, E2x2, E3x3, E4x4, E5x5 depositions E1/E4, E4/E9, …, E9/E25 ratios Percent of E in Barrel, Endcap, Preshower Longitudinal shower development Low Level Test: Single 30 GeV photons (2,000 events) E25 resolution vs the incident energy Longitudinal shower development vs energy Coefficient of Lead absorption vs incident energy (preshower) High Level Test: Single 10GeV, 20GeV, 30GeV, 40GeV, 50GeV (2,000 events)

9. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 9 Ecal Validation (II)

10. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 10 Hcal Validation Hadronic Calorimeters: Hcal Barrel – Hcal Endcap (copper/scint.) Hcal Forward (steel/quartz fibers) E depositions in each HB layer Time dist. of Hit energy in 7x7 tower matrix Number of hits in Ecal and Hcal Energy in 1x1, 3x3, 5x5 tower matrices Single 50 GeV pions (1,000 events) Layer 0 Time distribution in 7x7 tower matrix Total energy in Hcal Total energy in long fibers (HF) Total energy in short fibers (HF) …………

11. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 11 Muon Validation Muon System: Drift Tubes (DT) in central region. Cathode Strip Chambers (CSC) in forward region. Resistive Plate Chambers (RPC) in both for trigger. Single 100 GeV muons (1,000 events) E lost by  in all full CMS detector For 100 GeV   ~8 GeV For each muon: Energy lost Deviation in position Deviation in angle (deg) Number of tracking steps For each type of muon process (ionization, bremsstrahlung, e+e− production, muon nuclear interaction, decay and capture): Energy of secondary particles Angle of secondary track with respect to primary muon track

12. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 12 Geometry Validation Computes the number of volumes and materials and the total number of radiation lengths through the CMS detector. Sample The geometry summary: number of different materials, number logical volumes, physical volumes. The number of radiation lengths after traversing the full detector. Validation Quantities 1,000  of E=10 TeV and random ,  (= neutral geantinos since physics/field off) Material Budget (ROOT tree, histos, or ascii file) For each Geant4 step of each muon: Accumulated track length, volume name, volume copy number, accumulated material budget (Number of radiation lengths), material radiation length. At the end of track: Accumulated material budget.

13. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 13 Field Validation Checks the tracking in the CMS magnetic field. The test compares the deviation at the end of the track in position and direction. 400 single muon events in four groups of 100 events with different energies: 1, 10, 100, 1000 GeV. The muons behaves as charged geantinos (physics is off). Change in track angle, momentum, kinetic energy. Sample Validation Quantities

14. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 14 Global Validation Sub-system packages: dedicated validation tests for individual sub-systems. Geometry sub-set, field off. Global package: validates entire detector with real field, using pp physics samples. For example, min-bias. 1.Monte Carlo Number of vertices from Geant4 Number of tracks from Geant4 Number generated particles Position (x,y,z) of each Geant4 vertex p T of each Geant4 track Energy of each Geant4 track 2. Electromagnetic Calorimeter Number of Ecal hits Energy of each Ecal hit Time of flight for each Ecal hit Global  of each Ecal hit Global  of each Ecal hit Number of preshower Hits Energy of each preshower hit Time of flight for each preshower hit Global  of each preshower hit Global  of each preshower hit

15. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 15 Global Validation (II) 3. Hadronic Calorimeter Number of hits Energy of each hit Time of flight for each hit Global  of each hit Global  of each hit 4. Tracker Number of Pixel hits Global  of each Pixel hit Global  of each Pixel hit Time of flight of forward Pixel hits Time of flight of barrel Pixel hits Global R of barrel Pixel hits Global Z of forward Pixel hits Number of Silicon hits Global  of each Silicon hit Global  of each Silicon hit Time of flight of forward Silicon hits Time of flight of barrel Silicon hits Global R of barrel Silicon hits Global Z of forward Silicon hits 5. Muon Number of hits Global  of hits Global  of hits Time of flight for DT hits Global R of DT hits Time of flight for CSC hits Global Z of CSC hits Time of flight for RPC barrel hits Global R of RPC barrel hits Time of flight for RPC forward hits Global Z of RPC barrel hits

16. CHEP06, Mumbai-India, Feb 2006V. Daniel Elvira 16 Summary & Outlook CMS simulation validation suite for hit derived quantities is operational – being ported to the CMSSW framework Iterate on validation quantities Optimize sample types, size, test tolerance values In progress: Expand Physics Validation Suite to include Digis (pulse shape, pedestals, gains) In the future: Incorporate reconstructed physics objects: jets, e, , 