Forward Silicon Vertex Tracking in PHENIX

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Forward Silicon Vertex Trackingin PHENIX

• Mike LeitchLANL Medium Energy Nuclear Physics
• Outline
• What can a forward tracker do?
• Physics Program available with FVTX
• What is LANLs role?
• Status

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What can a forward tracker do?

• Silicon Vertex Tracker for Forward Rapidity
• 4 layers of silicon accurately measuring vertex
  displacement, track trajectory at forward
  rapidity
• Greatly enhances physics reach of PHENIX Muon
  System
• Complements Barrel Tracker which will cover
  central rapidity

Typical decay distances D 500 µm B 1,300
µm Resolution ?ZVTX 170 µm
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First Explicit Beauty Measurement Requires FVTX

• Physics Motivation
• Open beauty measurement needed to separate charm
  and beauty components from single lepton
  measurements
• Only explicit measurement of open beauty
• Relatively free of background because prompt AND
  displaced B-decay vertex can be reconstructed
• Additionally, c and b may be separated by
  different lifetimes of D, B

(cm)
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Physics Program Available with FVTX

• New Measurements become Feasible with Muon arms
  and Improve All Existing Muon Measurements
• Allows direct measurement of beauty via B ? J/?
• Open Heavy Flavor can be extracted with precision
  from single muon background
• W from single muons can be extracted to lower pT,
  background reduction
• Drell-Yan measurements become feasible with
  separation from heavy-flavor

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Spin Physics Measurements with the FVTX

• Open heavy flavor ? gluon polarization.
  Precision measurement only possible with large
  reduction of backgrounds
• W ? sea quark polarization. Broader kinematic
  range and background reduction with addition of
  FVTX
• Drell-Yan ? valence and sea quark polarization.
  Extraction of Drell-Yan continuum from open
  heavy flavor and combinatorial background only
  feasible with FVTX
• Entire muon arm spin program is broadened and/or
  improved with addition of FVTX

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Cold Nuclear Matter Measurements with the FVTX

• Only way to directly measure beauty production,
  via B?J/?
• Entire spectrum of onia measurements can be
  explored only with FVTX
• Likely only way to access ? with precision
• J/? and ? measurements with improved resolution
  and background rejection provided by FVTX
• Combination of all measurements necessary to
  untangle various cold nuclear matter effects
• Open heavy flavor measurements can only be made
  with addition of FVTX which can significantly
  reduce backgrounds
• Also critical in combination with above to
  untangle CNM effects
• Drell-Yan measurements to help understand energy
  loss
• Entire muon arm CNM program is broadened and/or
  improved with addition of FVTX

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LANLs Role

• FVTX
• Project manager - Melynda Brooks
• Successfully passed BNL review and submitted to
  DOE for FY08 funding
• LDRD
• Obtained 1.25M/year grant from LANL to put in
  small acceptance vertex tracker, and work with
  T-division on expanding theory
• Pat McGaughey PI, Emil Mottola (T-16) co-PI
• Will share readout technology and analysis
  techniques with FVTX so will advance FVTX in
  addition to getting early physics
• VTX
• Major responsibility in mechanical structure

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Status

• FVTX
• Proposed construction start in FY08
• Calculated installation complete in FY10
• Cost of 4.5M
• LDRD
• Grant covering FY06 thru FY08
• Expected installation before FY09
• Precise heavy flavor measurement via single muons
  will be obtained
• Work on technical issues already in progress

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Summary

• Addition of FVTX/LDRD silicon trackers will
  greaty enhance the spin physics and cold-nuclear
  physics program attainable with the PHENIX Muon
  Arms
• LANL has lead the effort on the FVTX proposal,
  successfully defended this to BNL, and external
  review committees and sent proposal to DOE.
• LANL has also brought critical funding through
  our LDRD grant which should provide much of the
  RD needed also for the FVTX project
• We look forward to the coming physics program
  with this critical detector addition