Transcript PPT

LAr Response to pions:
Data vs MC
S.Paganis (Wisconsin)
with
Isabelle Winterger ,Martin Aleksa
LAr Week CTB Meeting,
CERN, 10-May-2005
Analysis (10.0.2 data+MC)
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Run: 2100482 20GeV pions
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Parabola Energy reconstruction
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Fully combined, have shown previously problems in LAr rec.
energy
15ADC “cubicADCcut” in LArRawChannelSimpleBuilder.cxx
mA2MEV numbers from EMTB
EMTB 3x3 clustering
No cluster corrections, No Long. weigths
No shower cuts yet.
MC: 20k events
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Charge collection corrections
Tried to get “correct” beam profile …
ADC2MEV in Digitization step (parabola is the default)
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Program Flow (release
CTB04 Data
10.0.2):
jobOptions.G4Ctb_Sim.py
+G4Apps
jobOptions.G4Ctb_Dig.py
MC: ADC2MEV happens here
Data: ADC2MEV here
Reconstruction
ESD and CBNT
Thanks to:
Manuel Galas
TBAnalysis on ESD
miniCBNT
Analysis C++
Package
Final Physics Plots
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ADC -> MeV for MC and Data (10.0.2)
Monte Carlo: LArdigitMaker.cxx
E Geant
ADC 
 Noise(ADC)
ADC2MEV mc  SFmc
E rec  ADC2MEV mc  ADC
Data: LArRawChannelSimpleBuilder.cxx
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E rec  ADC2MEV  ADCpeak  PEDESTAL
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ADC2MEV  ADC2DAC  DAC2uA  uA2MEV visi  (1 / SFdata )
Differences at present:
1. Difference in the Sampling Fractions
2. Different noise normalization due to ADC2MeV (small)
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Data: 3x3 LAr vs Total tile Energy
Pion LAr MIPs
Electrons
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Beam Profiles
MC
Data
Can do better
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Cleaning cuts
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For reconstructed energy comparisons:
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For visible energy comparisons:
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E(MC) = Erec * SFmc/SFdata
E(MC) = Erec * SFmc
E(data) = Erec * SFdata
muTag to remove muons
Etile+ELAr MIP cuts to remove muons
ELAr>15GeV, to remove electrons (crude)
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Don’t want to use shower shape cuts yet (under study)
Possible Long electron tail
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Possible biases:
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Tile MC has no noise.
For data a LAr drift time assumption is made
to get the SF
LAr MC has noise but it does not perfectly
represent the data
Cuts on LAr energy cause a bias when scale
and shape are different
Parabolic fit at low energies?
...
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MuTag: removes a portion of muons
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Zoom in the “MIP” region (after cuts)
OLD Plot: April 2005:
we care because MIP region is upstream material insensitive!
MC is broader, slow rising:
due to more noise or the
parabola or …?
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Noise: ADC[2] eta=10, phi=8
DATA
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MC
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Noise: ADCpeak
DATA
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MC
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Noise: Reduce the MC noise to 0.6
DATA
MC
Great match! However …
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Noise: ADCpeak still wider!
DATA
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MC
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Zoom in the “MIP” region (after cuts)
New Plot: after reducing accordion noise in MC.
we care because MIP region is upstream material insensitive!
Improved agreement and an indication
of the MC EM scale being a few % too
low. However, in the data 5ns ~ 1%
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LAr Energy after simple cuts
Some disagreement between data and
MC after only SF adjustment.
It seems that there is additional upstream
material, not present in the simulation.
Data
MC
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Visible Energy per LAr Sampling
Normalization
away from the
noise region
Less energy in MC
More energy in MC
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Total visible Energy (LAr)
Normalization
away from the
noise region
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Summary
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Reasonable but not perfect agreement
between Data and MC:
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Discrepancy between DATA and MC for very
small depositions was resolved:
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MIP region indicates lower EM MC response (few %)
Strips vs Middle response indicates some missing material in
the MC description (must be checked).
due to inconsistent noise in MC and
due to the ADCpeak parabola calculation (move to OFCs)
Tile colleagues confirmed MC improvement.
Will try to communicate the present
progress. Next round, use OFCs
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Supporting Viewgraphs
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ADC2MEV (Data vs MC)
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Erec  ADC2MEV  ADCpeak  PEDESTAL
How:
PS (EMB1)
S1 (EMB1)
S2 (EMB1)
S3 (EMB1)
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ADC2DAC
Ramps
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DAC2Volt
Volts2mA
mA2MeV
38.147
uA/Volt
Injection
Resistor
(tdrift*W)/e *
1/SF
38.147/R=0.114 nA
12.62 nA
37.58 nA
37.58 nA
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370.3703
370.3703
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How to get the SF for Data (an example)
uA2MEV  uA2MEV visi  (1 / SF)  SF  uA2MEV visi / uA2MEV
EMTBeam Reconstruc tion :
Presampler :
|  | 0.8
MeVper mA  420ns  23.6eV / 1.6 10 19 C
Accordion :
1250 MeV/ mA Presampler
19
MeVper
m
A

470
ns

23
.
6
eV
/
1
.
6

10
C
370.37 MeV/ mA Accordion
|  | 0.8
1176.47 MeV/ mA Presampler
328.947 MeV/ mA Accordion
SF(Presampler <0.8)=t*W/e/1250 = 0.0496
SF(Accordion <0.8)=t*W/e/370.37 = 0.18718
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