Simulations: resolution, occupancy,

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Simulationsresolution, occupancy, ,for the
barrel

• Silicon upgrade workshop in Nashville
• June 9, 2003
• Yuji Goto (RIKEN/RBRC)

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Physics goals of silicon vertex detector

• heavy-ion physics
• modification of gluon structure in nuclei
• gluon shadowing
• properties of earliest, densest stage of AuAu
• charm enhancement
• charm baseline for J/y suppression
• energy-loss of high-pT heavy quarks
• spin physics
• gluon polarization in broad xBj range
• prompt photon jet production gluon Compton
  process
• heavy flavor production gluon fusion
  process
• flavor contents of quark polarization
• weak boson production
• transversity
• particle correlation

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Strawman
Channels Occupancy (central AuAu)
barrel 1st pixels 1.3 M lt1
barrel 2nd strips 92 K 12
barrel 3rd strips 123 K 7
barrel 4th strips 154 K 5
endcaps pixels 2.8 M lt3
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XBj coverage before and after

• figure for the LoI presentation in March
• ?s 200 GeV, full luminosity 320 pb-1
• S/N gt 1
• statistics event gt 100-1000

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Photonjet measurement

• S/N will improve ?
• S/N gt 1 for pT gt 5 GeV/c after isolation cut
• xgluon 2pT / ?s gt 0.05
• jet-axis resolution ?
• kinematic reconstruction
• how much advantage ?
• improvement of isolation cut ?

inclusive ?
inclusive ?
xg calculated by xg2pT/?s
? leading hadron
xg calculated by kinematic reconstruction
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Single-electron measurement

• mid-rapidity sources of electron
• remove Dalitz via vertex cut
• charm pT(e) lt 3 GeV/c
• beauty pT(e) gt 3 GeV/c

by Vladimir Rykov
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Electron DCA resolution

• 50mm x 425mm pixels, full multiple scattering
• DCA resolution (electrons) lt 50 mm at moderate pT
• less than c?, D0 125mm, D? 317 mm

by Johann Heuser
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cc?eX

• S/N will improve by displaced vertex
  identification
• baseline pT 2-4 GeV/c ? xgluon 0.05-0.1
• upgrade pT 1-4 GeV/c ? xgluon 0.01-0.1

by Wei Xie
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cc?DX

• pT gt 4 GeV/c ? xgluon gt 0.1
• triggering ?

by Iowa group
D?K- p p (BR 9)
Lc
D0?Kp pp 30k/year AuAu 10K/year
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bb?e/?displaced-vertex

• statistics will improve
• 30 times larger statistics
• baseline xgluon 0.04-0.15
• upgrade xgluon 0.02-0.3
• triggering is necessary

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B?J/?X

• J/??ee
• baseline xgluon 0.02-0.06
• B?J/??ee
• upgrade xgluon 0.03-0.1 or narrower

J/?
B?J/?
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More studies to do

• resolution, occupancy,
• how much occupancy in the heavy-ion environment
  realistically ?
• how to survive it ? pattern recognition,
  tracking,
• matching to central arms
• jet-axis resolution ?
• S/N, statistics, how to pin-down xgluon,
• others
• triggering
• ?s 500 GeV
• other channels bb?eX,