Inkyu

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Inkyus X - FILE Local Compactness
21st Century PHOBOS presents
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Motivation Flow systematics

• Is Flow the unique source E-by-E modification of
  dN/dhdf ?
• STAR showed Jet-ness at RHIC
• - v2 Flow (x) Jet (1-x )

Jet
Dilution
Enhancement
Can we do STAR-like jet study? Dont have Pt
trigger If yes, 1) useful for Flow systematics,
2) potential new physics menu
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E-by-E Jet-finding from dNh/dhdf

• dN/dh flat from h-2 to h2.
• full azimuthal acceptance, f-p to fp.

Similar to v2

• Need to correct Octagon acceptance (phase space,
  cracks).
• Need to fix Hot/Dead channels, fix CMN problem.
• Need to apply 2D Poisson correction, Occ(h,f).

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ATLAS/MGS algorithm Local Compactness

• Designed for Top quark mass, Heavy-Higgs search
• Dynamical Jet size variation, give the best Jet
  energy calibration
• Image Processing method, Rely on compactness, No
  license fee

AHD (Average Hit Density) hits / Total
Area LHD (Local Hit Density) hits inside /
window size
LC LHD/AHD
AHD 24/(2p x 4) 0.95, LHD 9/(p r2 )
4.47 LC 4.7!
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A typical LC event peripheral
LCgt2
PR01 data (Flow)
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A typical LC event peripheral
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A typical LC event peripheral
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A typical LC event peripheral
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A typical LC event mid-central
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A typical LC event mid-central
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A typical LC event most central
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of LCs peripheral events
MC shows more LCs (Flow, Fluctuation)
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of LCs mid-central events
Starting from bin 4, Data show more LCs (Jet-ness
?)
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of LCs central events
Data show 3 or 4 times more LCs, even di-jets
(Jet-ness !)
4 times higher Prob
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Summary

• Data show higher Prob. of Local Compactness!
• much more than the contribution from Flow
• Are they Jets? CMN problems? Secondary shower?
• important source of Non-flow correlation
• At best, can be a new physics menu
• We have larger acceptance (-2 to 2). STAR -0.7
  to 0.7
• At worst, can be used for v2 systematics
  (non-flow)
• Still long way to go, to get a conclusion