PHENIX Detector Upgrades for Spin Physics

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PHENIX Detector Upgrades for Spin Physics

• Itaru Nakagawa
• RIKEN/RBRC
• On behalf of PHENIX Collaboration

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• 2 central arms
• electrons, photons, hadrons
• charmonium J/?, ? -gt ee-
• vector meson r, w, ? -gt ee-
• high pT po, p, p-
• direct photons
• open charm
• hadron physics
• 2 muon arms
• onium J/?, ?, ? -gt mm-
• open heavy flavor
• W -gt m (500GeV)

Excellent trigger and DAQ capabilities multiple
trigger signature important for spin physics can
be taken in parallel with high bandwidth!
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PHENIX Upgrade Projects

• Vertex Trackers
• Barrel VTX and Forward VTX
• Electromagnetic Calorimetry
• MPC
• Nose Cone Calorimeter
• Muon Trigger Capabilities
• Resistive Plate Chambers
• Muon Tracker Front End Electronics

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PHENIX Baseline Acceptance
Muon Arm
Muon Arm
EMCAL
0 f coverage 2p
EMCAL
-3 -2 -1 0
1 2 3
rapidity
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Barrel VTX
38.2cm

• High offset resolution lt 50?m
• D0 123?m
• B0 460?m

15cm

• Inner 2 layers Pixel
• Outer 2 layers Stripixel

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Forward VTX

• 4 layers
• Vertical planes
• 75?m radial pitch, 7.5o ? segmentation

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Baseline Acceptance (BarrelForward) VTX
BarrelForward VTX
Muon Arm
Muon Arm
EMCAL
0 f coverage 2p
EMCAL
-3 -2 -1 0
1 2 3
rapidity
VTX and FVTX add charged particle tracking close
to the event vertex over a wide kinematic range.
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Gluon polarization DG (Heavy Flavor)
Polarized pp collisions
Gluon polarization can be measured by double-spin
asymmetry ALL.
Gluon Polarization

• charm and bottom identification by displaced
  vertex
• Jet identification with larger acceptance

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Muon Piston Calorimeter
412 PbWO4 crystals 3.1 lt ? lt 3.7
?? Transverse Single Spin Asymmetry
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Nose Cone Calorimeter (NCC)

• ge identification
• g p0 separation
• e/m isolation
• jet identification
• e/g/jet triggers
• dE/dx

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Baseline Acceptance Calorimeters
Muon Arm
Muon Arm
EMCAL
0 f coverage 2p
EMCAL
VTX FVTX
-3 -2 -1 0
1 2 3 rapidity
NCC and MPC add EM Calorimetry in the forward
direction.
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Gluon polarization DG(x) (Direct Photons)

• ?-jet is
• Very clean way to measure the gluon
• Measuring the angle of the jet gives you access
  to xgluon

x
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sqrt(s)500 GeV _at_ RHIC
?
Clean flavor separation w/o fragmentation
uncertainty
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Hardware Requirement for W
Design Luminosity vs 500 GeV s60mb L
2x1032/cm2/s
Total X-sec rate12MHz
m momentum distribution
REAL DATA
DAQ LIMIT 1-2kHz (for µ-arm)
Required Rejection Factor 10,000
Need to Implement PT Sensitive Trigger!
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PHENIX Muon Trigger Upgrade
R2
R3
R1(ab)
r3.40m
MuTr
Rejection 12,000, beam background immune.
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Muon Trigger Front End Electronics
Utilize 5 of signal charge to send MuTR
information to trigger logic
To trigger Logic
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ADC
95
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High - PT Trigger Algorithm
Candidates found by matching RPC1/2 hits within
angular range. Momentum cut made by matching hit
in MuTr station 2 within three cathode strip2 of
RPC projection.
(MuID LL1 1D Trigger also required.)
(RPC3 hit also required in three inner theta
rings)
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Flavor Separation by ALW/-
?Ldt800pb-1, P0.7 projected _at_500GeV
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Upgrade Schedule
RD Phase
Construction Phase
Ready for Data
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Physics Timeline
see Spin report to DOE http//spin.riken.bnl.gov/
rsc/
L 1x1031cm-2s-1
6x1031cm-2s-1
1.6x1032cm-2s-1
P 0.5 0.6 0.7

vs .. 200 GeV ......... 500
GeV
2005 2006 2007
2008 2009 . 2012
(RHIC II)
10 pb-1 ?275pb-1
.. 980pb-1
_at_ 200GeV
_at_ 500GeV
Inclusive hadrons Jets 25 Transverse
Physics Charm Physics

direct photons
bottom physics

W-physics
ALL(hadrons, Jets)
ALL(charm)
AL(W)
ALL(?)
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Summary

• PHENIX Upgrades provide wide variety of spin
  observables
• Barrel and Forward VTX
• ?G measurement by heavy flavor displaced vertex
• Electromagnetic Calorimetry NCC and MPC
• ?G Direct photon and ?0 in low x
• Sivers and Collins functions
• Muon Trigger Upgrade RPC and MuTR FEE fast
  trigger
• Flavor separation of quark/anti-quark spin
  structure functions through W boson production