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Root analysis tools for LCD

M. Iwasaki University of Oregon


LCD Simulation Study Flow
Generator PANDORA-PYTHIA , PYBMS, PYTHIA, ISAJET,...

Output: stdHEP (HEPEVT common) Simulator Fast Simurator Full Simurator (GISMO)

Output: Ascii raw data Convert root or lcd data Event Analysis Root (using C++) or JAS (using JAVA)


LCD Analysis with Root
FastMC ÇTrack .. Smear & bend charged particles Set error matrix (B.Schumm)New! ÇCluster .. Smear particle position & Energy Cluster merging tool New! ÇTrack .. Smear charged particle Apply min-Hit & min-PT cut ÇCluster .. Make 1 cluster from 1 particle by Cluster Cheater
New!

FullMC

Analysis tools ÇJet Finder ... 3 kinds of algorithms ÇThrust Finder New! ÇParticle extrapolation New!


Tracks at Root
FastMC

Maintained by R.Dubois FullMC
TrkMult Nent = 100 TrkMult Nent = 100 Mean = 37.84 RMS = 12.93 Mean = 48.35 RMS = 15.37

10

14

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12

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4 2 2

0 0

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0 0

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Charged Track multiplicity


Tracks at Root
FastMC
220 200 180 160 140 140 120 120 100 100 80 60 40 20 0 0 80 60 40 20 0 0
TrkE Nent = 4835 Mean = 2.678 RMS = 2.35

FullMC
200 180 160

TrkE Nent = 3784 Mean = 2.468 RMS = 2.273

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Energy (GeV)


Tracks at Root
FastMC
70 90 80 70 60 40 50 40 30 20 10 10 0 -1 -0.8 -0.6 -0.4 -0.2 -0 0 -1 -0.8 -0.6 -0.4 -0.2 -0 30 60

FullMC

50

20

0.2 0.4 0.6 0.8

1

0.2 0.4 0.6 0.8

1

cos


Tracks at Root
Now we have track helix parameters and error matrix
300 900 800 700 200 600 500 400 300 200 50 100 0 0 0 0 100 150 250

0.01

0.02

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0.05

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Impact parameter

(cm)

Normalized Impact parameter (FastMC)


900 800 700 200 600 500 400 300 200 50 100 0 0 0 0 100 150 250

0.01

0.02

0.03

0.04

0.05

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Impact parameter

(cm)

Normalized Impact parameter (FullMC)


Clusters at Root

by J.Bogart Clusters

250

200

(cm) R
cluster

150

100

50

0 -300 -200 -100 0 100 200 300

Zcl

uster

(cm)

(Fast MC)


Clusters at Root
Calorimeter Hits
250 250 200 200

Clusters

(cm)

100

R
-300 -200 -100 0 100 200 300

cluster

150

(cm)

150

R

hit

100

50

50

0

0 -300 -200 -100 0 100 200 300

Zhit (cm)

Zcl

uster

(cm)

(Full MC)


Clusters at Root
Fast MC
450 400 4000 350 300 3000 250 200 2000 150 100 50 0 0 0 0 1000
ClsE Nent = 9358 Mean = 2.527 RMS = 2.273

Full MC
5000

ClsE Nent = 19752 Mean = 1.236 RMS = 1.859

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Cluster Energy(GeV) Energy scale for Full :: determined by Å


Thrust Finder Translate from G.Bower's code
tt events
60

2 lepton (ÅÅ or ) events
160 140 120

50

40 100 30 80 60 20 40 10 20 0 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 1 0 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 1

(Thrust)

(Thrust)

Works well!


Jet Finder Translate from G.Bower's code
Currently we have 3 kinds of algorithms .. Jade , Jade E, and Durham Comparison of SLD's Jet Finder (fortran) and ours SLD(Fortran) NLD: Root (C++)
200 180 160 140 120 100 80 60 40 20 0 0 200 180 160 140 120 100 80 60 40 20 0 0

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(tt 6jets event)

# of Jets

# of Jets

Works well!


Analysis example : b-tag by N

sig

method

Using Jet Finder & Normalized impact parameter, we can tag b-jet ÇCount # of significant tracks (> 3impact) Nsig ÇNsig 4 ... regard as b-jet
3000 2500

2000

uds c b

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N

sig

(FastMC)


Analysis example: b-tag by N

sig

method

Reconstruction of t-quark mass in tt 6jets event Without b-tag
220 200 180 70 160 140 120 100 80 60 20 40 20 0 100 120 140 160 180 200 220 240 260 10 0 100 60 50 40 30 90 80

With b-tag

Signal BG
120 140 160 180 200 220 240 260

Mass (GeV/c2)

Mass (GeV/c2)

(FastMC)


Particle Extrapolation
Modified from J.Bogart's particle swim code
Neutral : Straight Charged : Helical extrapolate to any radius

Example 1: Extrapolate McParticles to Calorimeter Hit
which is from same McPart, and see the distance
200 180 14 160 140 120 100 80 6 60 4 40 20 0 0 2 0 0 12 10 8

e, photon

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hadrons

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(cm)

(cm)


Particle Extrapolation Example 2: Extrapolate Charged tracks to a Cluster radius
and see the Cluster-Track matching distance

Cluster = Track
1000 60 800 50

photon

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30 400 20 200 10

0 0

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(cm)

(cm)


Cluster merging for FastSM



Merge the clusters when < max

Cluster merging .. Start from the Highest energy cluster


Helper program for LCD Root analysis
URL: www-sldnt.slac.stanford.edu/nld/documentation/Tutorial/MyEvent.htm

ÇOpen Input root files ÇAccess events ÇClear Histograms ÇDirect histograms to file


Summary
Ç Root analysis tools work well! Ç We have a lot of things to do Test and debug the tools Track Finder & Fitter Clustering b-tag with topological-vertex finding ...... Need Volunteers!! The other examples of Root Analysis will be shown at 1:45 and 3:45!