Elliptic Flow Estimates For Simulated Data in PMD

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Elliptic Flow Estimates For Simulated Data in PMD

• Sudhir Bhardwaj
• University of Rajasthan

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• Motivation
• Elliptic Flow
• Simulation
• Conclusion
• Future Plans

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Motivation

• We want to study elliptic flow of photons in real
  data.
• For that we are doing simulations with nearly
  similar conditions which is present in the real
  data.

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Elliptic Flow
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Elliptic Flow
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Simulation

• MEVSIM
• GEANT
• BFC

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MEVSIM

• MEVSIM is an event generator.
• It provides uncorrelated A A collision events.
• Input to MEVSIM
• No. of events
• particle type their multiplicities
• anisotropic flow values.
• We put a certain flow value in each event and
  check how much we can measure from our detector.

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Big Full Chain (BFC)

• BFC is the STAR software reconstruction chain.
• Outputs of BFC chain for simulation which we are
  using
• .event.root
• .geant.root

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Procedure

• We Input 10 elliptic flow in MEVSIM for the
  particles . In the ? range -1.3 to
  -4.7.
• For the multiplicity AuAu 200GeV. We got .nt
  files
• We run geant year 2004 geometry by using .nt
  files and got .fzd files.
• We used .fzd files for making root files by
  running BFC chain.

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Procedure cont.

• We got azimuthal angle F and Reaction Plane angle
  ?.
• We fit (F - ?) distribution by the following
  function.
• 1 2V1 cos(F - ?) 2V2 cos2(F - ?)

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(F-?) distribution for elliptic flow
Input V2 is 0.1 and output is 0.099 for hadrons
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Photon Track and Cluster V2 comparison
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Photons Split Cluster and Original Cluster V2
Comparison
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Photons Split Cluster and Original Cluster and
Tracks V2 Comparison
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Ratio of Number of Photon Clusters and Photon
Tracks
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Ration of Number of Split Photon Clusters and
Photon Tracks
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Background and Original Hadrons V2 Comparison
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Ratio of Hadron Tracks and Hadron Clusters
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Conclusions

• Photon Tracks V2 dont change with Multiplicity.
• Photon Cluster V2 decreases with increasing
  Multiplicity.
• Hadron Tracks V2 dont change with Multiplicity.
• Hadron Cluster V2 decreases with increasing
  Multiplicity.

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Future Plans

• We will try to find the reasons of the results
  which are still not understandable.
• We will do elliptic flow analysis with
  experimental data.

Thank You
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Backup Slides
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Multiplicity of p,p- and p0 at AuAu
200GeV(HIJING)Eta (-1.3 to -4.7)
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Geant Output (For an event)
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Edep and Ncell Cuts

• We used 3 MIP Edep and Ncell gt 1 cut for
• differentiating photons from hadrons.

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Comparison of Edep ,Ncell cuts with photons
cluster
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Comparison of Edep ,Ncell cuts with hadrons
cluster
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Event Plane Angle
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Ratio of Number of Photon (Tracks Clusters)/
Photon Tracks
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Ratio of Split Photon Cluster and Original Photon
Cluster
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Ratio of Background and Original Hadron Clusters
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How Photon Cluster merging effects V2
If V2 effect present
If photon cluster merges