Slovak contribution to experiment ATLAS

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Slovak contribution to experiment ATLAS

• Even though Slovakia is small country with
  limited finances we have fulfilled all our
  obligations at experiment ATLAS.
• Slovak contribution is well known within the
  ATLAS community

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CERN
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Experiment ATLAS
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ATLAS cavern
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ATLAS cavern
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Slovak ATLAS community

• All members of Slovak ATLAS group are involved in
  calorimetry
• HEC group ( D. Bruncko)
• TileCal group (S. Tokár)

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HEC activities

• Main obligation of Slovak HEC group is the
  electronic calibration system for HEC
• Part of the system was cold test software
• Other part of the system is calibration within
  all beam tests
• The group is involved at MC simulation software
  development as well

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HEC cold tests

• Within the HEC sub-detector construction, Slovak
  group was responsible for cold-testing software
  development
• Totally 132 modules were cold-tested
• No delay was caused due to our software
• Project was successfully finished at 2003

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HEC cold tests
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HEC beam test calibration

• Software for calibration data acquisition and
  analysis was developed
• Quality check using the calibration data

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HEC beam test calibration
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Beam tests MC simulation
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Geant4 physics validation

• Geant4 is still under development therefore
  authors need a feedback from users
• Precise comparison of simulated and experimental
  beam test data was used to verify hadronic
  physics at G4 environment

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Geant4 physics validation
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TileCal activities

• Test Beam Data reconstruction
• PMT Tests using the Single Photoelectron Analysis
• Top Quark Physics determination of the top
  quark charge
• Fast MC simulation of Calorimeter Response

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TileCal activities

• Test Beam Data reconstruction
• PMT Tests using the Single Photoelectron Analysis
• Top Quark Physics determination of the top
  quark charge
• Fast MC simulation of Calorimeter Response

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Test Beam Data Reconstruction

• Data from Test Beams analysed
• Calorimeter response to pions investigated
  (linearity, homogeneity, energy resolution)
• A method of energy reconstruction using topology
  of hadronic shower proposed

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PMT Tests using Single p.e. Analysis

• TileCal PMTs tested using the single ph.e. method
  elaborated in Bratislava
• PMT excess factor found (needed to find the
  energy to signal factor)
• Details of PMT structure seen (1st dynode effect)

A PMT spectrum analysed by the single p.e. method
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Top Quark physics

• Possibility of the ATLAS exp. to determine the
  top quark charge (2 approaches)
• Via radiative top production (
  ) matrix elements implemented
  into PYTHIA
• By the charges of top decay products
• Results The Atlas has a capability to determine
  the top charge in one LHC year (10 fb-1 sample)
  for both approaches

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Fast MC Simulation of the ATLAS Calorimeter

• The fast MC code for TileCal created ? works
  1000 ? faster than the full simulation
• Works continue to create the fast MC for full
  Calorimeter

Fast MC vs Test beam data
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Conclusions

• In addition to electronic calibration now we
  start to deal with physics calibration. 1-5th
  Dec. 2004 we organize the workshop concerning
  this topic
• ATLAS software (Athena framework) independent
  validation

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Conclusions

• Precise analysis of detector (calorimeter)
  physics with the aim to improve detector
  performance.
• Focusing to some processes of possible physics
• More experienced physicists are expected to come
  back to Slovakia