Layout of the ROOT Files

• 40 MeV - First Si Pixel Layer
• 150 MeV - Three Si Pixel Layers
• 0.5 - 0.9 GeV - Will Tracker

Hits -- Read-Out Unit Schema (ROU)

• ROOT Location (Pixel Detectors):
  • TrackerHitsPixelBarrel
  • TrackerHitsPixelEndcap
• ROOT Location (Strip Detectors -- LowTof and HighTof ):
  • TrackerHitsTIB (Tracker Inner Barrel)
  • TrackerHitsTOB (Tracker Outer Barrel)
  • TrackerHitsTEC (Tracker End Cap)
  • TrackerHitsTID (Tracker Inner Disc?)
  • TIB, TOB, TEC, TID Source
  • Strips -- integration time 12 ns, Pixels -- integration time 25 ns "In the first of these we load only the Hits with ToF smaller than a certain threshold (12.06 ns x 3), in the other those with bigger Tof." -- Source
• Source: SimDataFormats/TrackingHIt/interface/PSimHit
• Members:
  • Local3DPoint entryPoint() const -- Entry point in the local Det frame
  • Local3DPoint exitPoint() const -- Exit point in the local Det frame
  • Local3DPoint localPosition() const -- Local position in the Det frame, halfway between entry and exit
  • LocalVector momentumAtEntry() const -- The momentum of the track that produced the hit, at entry point.
  • LocalVector localDirection() const -- (Deprecated, use momentumAtEntry().unit())
  • Geom::Theta thetaAtEntry() const -- fast and more accurate access to momentumAtEntry().theta()
  • Geom::Phi phiAtEntry() const -- fast and more accurate access to momentumAtEntry().phi()
  • float pabs() const -- fast and more accurate access to momentumAtEntry().mag()
  • float timeOfFlight() const -- time of flight in nanoseconds from primary interaction to entry point (may become negative due to bunch assignment)
  • float tof() const -- (Deprecated, use timeOfFlight())
  • float energyLoss() const -- The energy deposit in the PSimHit , in ???.
  • int particleType() const -- PDG code, may differ from SimTrack id, happens if hit from secondary track
  • unsigned int detUnitId() const -- DetUnitNumber (must be created on its own)
  • unsigned int trackId() const -- SimTrackID of "mother" track -- intepreted in context of SimEvent to which PSimHit belongs
  • unsigned short processType() const -- ID of physical process that created track, produced hit (useful for secondary interactions)

Clusters

• ROOT Location: SiPixelClusterCollection_pixClust__Clusterization.obj
• Source: DataFormats/SiPixelCluster/interface/SiPixelCluster
• Members:
  • .container
    • (not accessible by functions) float theSumX;  // Sum of charge weighted pixel positions.
    • (not accessible by functions) float theSumY;
    • (not accessible by functions) float theCharge;  // Total charge
    • int minPixelRow() const; // Minimum pixel index in the x direction (low edge).
    • int maxPixelRow() const; // Maximum pixel index in the x direction (top edge).
    • int minPixelCol() const; // Minimum pixel index in the y direction (left edge).
    • int maxPixelCol() const; // Maximum pixel index in the y direction (right edge).
    • float x() const const;
    • float y() const const;
    • int size() const const; // Number of pixels
    • bool edgeHitX() const;
    • bool edgeHitY() const;
    • int geographicalId() const; // The geographical ID of the corresponding DetUnit
  • Source: DataFormats/SiPixelDetId/interface
    • PixelSubdetector : Pixelbarrel=1, BixelEndcap =2
      • For Barrel: layer(), ladder(), module()
      • For Endcap:
    • PixelModuleName : isBarrel()
      • -> PixelBarrelName : layerName(), moduleName(), ladderName(), isFullModule()
      • -> PixelEndcapName : endcapName(), diskName(), bladeName(), pannelName(), plaquetteName()
    • PXBDetId : layer(), ladder(), module()
    • PXFDetId : side(), disk(), blade(), panel(), module()
  • .thePixels
    • float adc; // Counts -- hit amplitude? (80 picoColumbs) -- amount of electrons that came out
    • float x;
    • float y;
• ROOT Location: SiPixelClusteredmDetSetVector_pixClust__Clusterization.obj
  • (Same objects as previous -- not sure of the difference)
• ROOT Location: SiStripClusteredmDetSetVector_ThreeThresholdClusterizer__Clusterization.obj
• Source: DataFormats/SiStripCluster/interface/SiStripCluster
• Members:
  • ._sets.id
    • short firstStrip();
    • unsigned int geographicalId(); // DetUnit
    • const std::vector& amplitudes() const;
      • The amplitudes of the strips forming the cluster.
      • The amplitudes are on consecutive strips; if a strip is missing the amplitude is set to zero.
      • A strip may be missing in the middle of a cluster because of a clusterizer that accepts holes.
      • A strip may also be missing anywhere in the cluster, including the edge, to record a dead/noisy channel.
    • float barycenter();
      • The barycenter of the cluster, not corrected for Lorentz shift; should not be used as position estimate for tracking.

-- BrianWilt - 29 Jun 2006