FAMOS A dynamically configurable system for fast Simulation and Reconstruction for CMS

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FAMOSA dynamically configurable system for fast
Simulation and Reconstruction for CMS

• CHEP 2003

Stephan Wynhoff Princeton University
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Simulation/Reconstruction Chain
Simulation OSCAR
MC 4-vector
MC 4-vector
Reconstruction ORCA
100-200 sec
SimHit
1-10 sec
RecHit / Digi
10-100 sec
FAMOS/ORCA
Analysis object
Analysis object
FAMOS/OSCAR
Start with fastest modeAIM 1000 times faster
FAMOS/ORCA
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Structure of FAMOS
StandaloneInterface
OSCARInterface
ORCAInterface
Generatorto Analysis
ShowerParameterization
Generatorto SimHit
Generator to RecHit
SimHit to Analysis
OSCAR
ORCA
DDD
COBRA (CARF/Utilities/GeneratorInterface)
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Reading Monte-Carlo Events
RawHepEvent
BaseHepEventReader
HepEventParticleGunReader
HepEventCmkinNtupleReader
HepEventG3EventProxyReader(COBRA/ORCA)
HepEventTxtReader
HepEventPythia6Reader(Pythia 6)
Who dispatches the events?
New class HepEventProviderNew class
FamosEventMgr
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Event handling

• Use RawHepEvent for communication
• FamosEventMgr reads the GeneratorInformation
• FamosEventMgr calls the simulation packages in
  sequence

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Reading the right Particles

• RawHepEvent contains ALL generator particles
• Filter to select subset
• Generation of new particles
• Bremsstrahlung
• Pair production
• .
• Ensure consistency
• Guarantee order (Tracker 1st, ECAL 2nd, etc.)
• currently user responsibility

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FamosEventMgr

• normal COBRA (framework) Observer
• Singleton
• accepts registrations of FamosSimulators
• reads RawHepEvent from DB or Pythia6, etc.
• use FakeRecReader to run without DB
• gives RawHepEvent to each FamosSimulator
• currently sequence of registrations
• keeps history of RawHepEvent (after each
  FamosSimulator)

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FamosSimulator

• Define abstract interface for each simulation
  module
• Implementation registers to FamosEventMgr
• Modules for
• Material effects
• Tracking
• Muon trigger

FamosSimulatorvirtual bool reconstruct
(RawHepEvent )virtual const string
giveMyName() constvirtual bool modifiesEvent()
const
BaseFastTracksFromGeneratorvirtual bool
reconstruct(RawHepEvent ) 0virtual
int nTracks (void) const0 virtual
SimpleTrack track (const int i)0
FamosTrajectoryManager
FML1Reconstructor
FTSIM
FATSIM
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Producing standard Objects

• FamosSimulator can use simple classes
• integrate to produce default framework Objects
  (RecObj)

LazyObserverltG3EventProxygt
FamosSimulator
BaseFastTracksFromGenerator
RecUnit
TRecUnitltTTrackgt
RecTrackFromParticle
FastTrackReconstructor
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Identical Interfaces to ORCA

• FATSIM Tracks
• myTrackFinder new RecTrackFromRawParticle(new
  FATSIM( myPtEG, myAngleEG, myEff,
  myImpactParameterEG))
• myTrackReconstructor new FastTrackReconstructor(
  myTrackFinder, "FATSIM")
• RecCollectionltTTrackgt MyTracks(ev-gtrecEvent(),"FAT
  SIM")
• Standard Tracks
• myTrackFinder new TrackReconstructor(new
  CombinatorialTrackFinder, "FkFTracks")
• RecCollectionltTTrackgt MyTracks(ev-gtrecEvent(),"FkF
  Tracks")

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Choosing the Event Source

• DB reading
• Code myEventMgr FamosEventMgrinstance()Li
  braries ltGroup nameGeneratorCARFReadergtltExtern
  al refCOBRA UseGeneratorInterfacegtltGroup
  nameRecReadergtltExternal refCOBRA
  useCARFgtInputCollections /System/SuperPU/Grea
  tEvts/GreatEvts
• Pythia reading
• CodeHepEventPythia6Reader myReadermyEventMgr
  FamosEventMgrinstance(myReader)Libraries
  ltlib namePythia6Interfacegtlt/libgtltGroup
  nameFakeRecReadergtltExternal refCOBRA
  useCARFgtInputCollections /Fake/Fake/Fake/Fake
  

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FAMOS Results
Tracker
90
Lvl-1 turn-on
single muon Pt gt 20 GeV
H -gt 4 mu
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Timing
fraction time/event msec
Framework 3 2
Pythia 40 25
FTSim 9 6
FastCalorimetry 34 22
Muon-Lvl1 5 3
Muon-Lvl3 9 6
cmsim ORCA 312500 200000
FAMOS is really fast
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Summary

• FAMOS mini-framework for fast simulation
  reconstruction
• Integrated in AND/OR independency of general CMS
  framework
• Flexibility to mix full and fast
  simulation/reconstruction
• minimal code changes
• selection by dynamically loadable shared
  libraries
• First Modules for Monte-Carlo to Reconstruction
  exist
• Tracks, Calorimetry, Muon Trigger, Muon
• Material effects, Bremsstrahlung, pair
  production, etc.
• Further extensions
• Geometry reading from standard XML description
  (to guarantee consistency)
• GFLASH, fast SimHits, RecHits, all the other
  options

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End of Presentation