Simulating the mass spectrum of Jand Upsilon

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Simulating the mass spectrum of J/??and Upsilon

• Ingrid von Glehn
• Angus Comrie
• University of Cape Town
• Supervisor Galina Shabratova
• Veksler and Baldin Laboratory of High Energy
  Physics

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ALICE

• Detector at LHC
• Studies heavy-ion collisions
• Large number of subdectectors
• UCT-CERN group focuses on Dimuon

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MUON Detector
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Grid Computing

• Large data volume from experiment
• Can be processed independently
• Split up tasks across processors in an organised
  fashion (tier model)?
• ALICE Grid (ALIEN)?

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J/??Suppression as a sign of QGP
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Simulation

• ROOT C interpreter and analysis package
• Pythia Particle transport / event simulation
• AliROOT Contains geometry of entire ALICE project

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Simulating the mass spectrum of J/??and Upsilon?

• Generate events using Pythia, only consider
  dimuon decays
• Apply Gaussian smearing to angles and momentum of
  muon pair
• Smeared mass histogram

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Results for J/??(1000 events)?
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Results for Upsilon (50000 events)?
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Background for charm pair

• More realistic situation, consider more decays
• Get an idea of what to expect
• Can look at particle code histogram to see major
  decays

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Background for charm pair
c,c
charmed mesons eg. D
p
p0
µ
strange mesons eg. K
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Background
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ALICE Experiment

• Can compare simulated data with experimental data
• Can simulate different decay processes and see
  which agrees with experiment
• Comparison of theoretical models