Calibration Status

1
Calibration Status

• online calibration
• pedestal calibration
• pulser calibration
• offline calibration (em)
• geometry dependent corrections
• scale-corrections Z?ee
• Et/pt studies at different energies
• energies in ?-cracks

2
Pedestal calibration strategies

• imminent deployment of new calibration databases
  and associated validation scheme ( ? status
  calorimeter meeting tomorrow)
• possible online calibration strategies
• pedestal reference run 10k events/gain path
  used for download and offline 0-suppression
• pedestal monitoring run 500 events/gain path
  used for monitoring pedestal drift ? drifted
  channels to be flagged, killed? updated?
• Pedestal Calibration Validation - flags and kills
  channels with
• incorrect mean/sigma values
• drift values

3
Pedestal calibration mean/sigma

• monitoring run 500 events
• mean 10? cut ? 470ltmeanlt770
• sigma 10? cut ? sigmalt40

4
Pedestal drift

• reference and monitoring run taken one after the
  other
• (mean-ref)?500/sigma 5? cut
• sigma-ref cut at 2?
• gain8/gain1 differences?

5
Pulser calibration strategies

• 3 standard set of linearity runs
• gain 8 80 steps of DAC-step 20 (20MeV)
• gain 8 80 steps of DAC-step 200
• gain 1 80 steps of DAC-step 1600
• monitoring pulser run
• free gain 2 steps DAC5000 and DAC15000
• timing calibration
• gain 8, DAC5000, 50 steps of delay5 (10ns)
• status
• 2 sets of gain/nlc calibration coefficients
  (2002/2003) taken at fixed timing
• no corrections applied

6
Pulser calibration offset

• determination of gain coefficients and nlc
  corrections
• negative pulser offset (i.e. DAC0 gives already
  a pulse) ? NLC corrections at small energies
• DAC-component exchanged on pulsers during
  shutdown
• possibility to download offset for each pulser
  (trigger studies)

Robert Zitoun
7
Pulser delay correction factors

• slope determined by linearity ramps depends on
  delay value
• correction factors can be determined for
  difference between delay used for calibration and
  delay at max. signal height
• but relative difference in delay corresponds to
  relative difference in timing for physics signal
  if not too far
• possibility to optimize delay per 1/6 of each
  pulser via automatic download

correction factors
Stephanie Beauceron
8
Pulser pulse shape corrections

• correction factors taking into account difference
  in signal shape between calibration pulse and
  physics signal
• determination from pulse shape simulation good
  agreement for calibration pulse, ambiguity for
  physics signal between scope measurement and
  triple sampling data
• triple sampling data with /-5 ticks

Sergey Burdin
9
em-calib geometry dep. corrections
CC
5 GeV
p13.06
p10
0,7 GeV
0,2 GeV
50 GeV
1,6 GeV
0,5 GeV
Anne-Marie Magnan

• ? important as long as no PS energies are used
• more important with p13.06
• no done for p13.08, smaller?

10
Energy in EC Calorimeter
EC
p13.06 energy from floors
50 GeV
p10
Not the same behaviour!
Anne-Marie Magnan
11
MC energy resolution
Run I Eta corrections p10 No correction p13 Eta corrections p13
s 0.15 0.202 0.006 0.19 0.01 0.199 0.008
b 0.16 0.23 0.10 0.59 0.08 0.42 0.08
c 0.003 0.004 0.002 0.0085 0.0014 0.0076 0.0014
CC
Anne-Marie Magnan

• higher noise term in MC p13 than p10 and in Run 1
• to be determined from data constant term?

12
scale correction Z?ee
Alexis Cothenet

• scale factors derived in calorimeter detector
  regions
• 1000 events with p13.05 data

13
Z-mass peak
Alexis Cothenet

• after all corrections
• 2 tracks matching required
• resolution larger than in MC

14
Et/pt comparison

• Et/pt comparison for different energy regions
  after geometry dependent corrections
• where are all these electrons coming from?
• ptlt 10 GeV underestimated?
• ptgt40 GeV overestimated?

1.00
1.10
0.97
1.01
MC Egen mean sigma 5 GeV 0.96 0.19 10
GeV 0.98 0.20 50 GeV 1.0 0.20 200 GeV 1.0 0.31
1.07
1.04
0.92
0.78
Oleg Kouznetsov
15
Et/ptresolution
Oleg Kouznetsov

• from p11 data

16
energy in ?-cracks Et/pt

• studies for p13 underway
• corrections with FH1 energy not possible after
  realistic MC simulation

Oleg Kouznetsov
17
Summary

• final online calibration procedure is (slowly)
  coming together
• better following of the calorimeter behavior
• better data quality
• correction to gain/nlc calibration to be studied
• good MC is crucial for offline calibration
  changes with p13.08 in geometry dependent
  corrections
• Z resolution not understood yet
• promising distributions from E/p