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Conditional Track Finder Performances
Riccardo RanieriINFN and Università di Firenze
Bτ Meeting27th November 2001
Conditional Track Finder Performances
Riccardo Ranieri 2Bτ Meeting27th November 2001
Track reconstruction
→Reconstruction of event tracks
→Collect RecHits from inside out for each track
→Start with first 3 RecHits (2 seed+1 next hit)
→Fit back the partial track with KFFittingSmoother
→Store the result
→Add next RecHit, fit back and so on...
Conditional Track Finder Performances
Riccardo Ranieri 3Bτ Meeting27th November 2001
KFFittingSmootherKFFittingSmoother::KFFittingSmoother()
{theFitter=new KFTrajectoryFitter(/* new PropagatorWithMaterial( alongMomentum),*/
new GtfPropagator( alongMomentum),new KFUpdator(100),new Chi2MeasurementEstimator(100) );
theSmoother=new KFTrajectorySmoother(/* new PropagatorWithMaterial( oppositeToMomentum),*/
new GtfPropagator( oppositeToMomentum),new KFUpdator(100),new Chi2MeasurementEstimator(100) );
}
Conditional Track Finder Performances
Riccardo Ranieri 4Bτ Meeting27th November 2001
Scanning of reconstruction performances in
6 pt bins (GeV/c) x 4 η bins
pt bins: 0.9 - 1.3 - 1.8 - 2.5 - 5.0 - 10.0 - ∞
η bins: 0.0 - 0.9 -1.3 -1.8 - 2.4
Scanning in η-pt plane
Conditional Track Finder Performances
Riccardo Ranieri 5Bτ Meeting27th November 2001
bb jets sampleSample used:bb jetsEt=200 GeV
gen: PYTHIA 6.158sim: cmsim 122OOdigi: ORCA 5_2_0
Analysis: ORCA 5_3_2
Conditional Track Finder Performances
Riccardo Ranieri 6Bτ Meeting27th November 2001
Resolution d0(5.<pt[GeV/c]<10.)
BARREL OVERLAP
11% over 2σ
6% over 3σ
16% over 2σ
10% over 3σ
Sim Track : theSimTrack.impactPointStateOnSurface().localPosition().x()
Rec Track : theAssRecTrack.impactPointState().localPosition().x()
Conditional Track Finder Performances
Riccardo Ranieri 7Bτ Meeting27th November 2001
12% over 2σ
8% over 3σ
Resolution d0(2.5<pt[GeV/c]<5.)
12% over 2σ
7% over 3σ
OVERLAP VERY FORWARD
Conditional Track Finder Performances
Riccardo Ranieri 8Bτ Meeting27th November 2001
10% over 2σ
4% over 3σ18% over 2σ
14% over 3σ
Resolution d0(1.3<|η|<1.8)
OVERLAP
Conditional Track Finder Performances
Riccardo Ranieri 9Bτ Meeting27th November 2001
Pull d0(5.<pt[GeV/c]<10.)
How well are d0’s reconstructed ?Very well !
Conditional Track Finder Performances
Riccardo Ranieri 10Bτ Meeting27th November 2001
Resolution zIP(0.<|η|<0.9)
Sim Track : theSimTrack.impactPointStateOnSurface().localPosition().y()
Rec Track : theAssRecTrack.impactPointState().localPosition().y()
8% over 2σ
3% over 3σ
BARREL
Conditional Track Finder Performances
Riccardo Ranieri 11Bτ Meeting27th November 2001
Resolution zIP
Problems with authomatic fit
OVERLAP
Conditional Track Finder Performances
Riccardo Ranieri 12Bτ Meeting27th November 2001
Pull zIP(pt[GeV/c]>10.)
Conditional Track Finder Performances
Riccardo Ranieri 13Bτ Meeting27th November 2001
Resolution pt(2.5<pt[GeV/c]<5.)
OVERLAPBARREL
Conditional Track Finder Performances
Riccardo Ranieri 14Bτ Meeting27th November 2001
Pull 1/pt(2.5<pt[GeV/c]<5.)
OVERLAPBARREL
Conditional Track Finder Performances
Riccardo Ranieri 15Bτ Meeting27th November 2001
ConclusionsOur goal is to have an efficient partial
track reconstruction to use for HLT
It can be possible to have goodmeasurement of track parameters with only 4/5 hits
All the plots shown (and many other more not shown) can be found at:
/afs/cern.ch/user/r/riccardo/public/Images
