PHENIX: The Next BUP and
the Next Decade
J. Lajoie
for the PHENIX Collaboration
5/14/2010
RHIC Spin Collaboration Meeting
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Charge from Steve Vidgor
ALD Steve Vigdor has charged PHENIX and STAR to write decadal
plans due August 1, 2010.
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Summarize detector upgrades underway and to be utilized in the
next 5 years.
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Compelling science beyond 5++ years that require additional
detector upgrades and machine capabilities.
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Prioritize the physics and the upgrades above.
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Discuss the option of an electron beam in the tunnel and thus an
ePHENIX and eSTAR in the MeRHIC and EIC era.
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Caveats
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The PHENIX BUP for Run11-12 is still in
development
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Still, it’s relatively straightforward
The PHENIX Decadal Plan is a moving target
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Active effort within the PHENIX Collaboration
As of now, there is no “official” Decadal Plan
What you will see is my take on the current process
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Of course, it’s probably biased
PHENIX has decided to THINK BIG!
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RHIC will have no future if it does not pursue exciting
new physics discoveries!
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The Next Five Years
Run-10
Run-11:
Silicon VTX on schedule.
Precision heavy flavor era!
Muon Trigger Upgrade on schedule!
Forward Wm
DAQ Upgrade on schedule!
Run-12:
Forward silicon VTX available.
Run-14:
Forward Calorimetry
(FOCAL proposal)
Critical to exploit the detectors to do
the physics they were designed for.
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High Precision Heavy Flavor
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The FOCAL
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Si-W calorimeter
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44cm from the interaction point
Replaces existing Cu nosecone
Modular Brick construction
Physics Goal
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Gluon PDF at low-x via direct
photons
This is a very new type of detector!
A hybrid between a calorimeter and a tracking detector
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The PHENIX Run-11/12 BUP
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Run-11:
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Anticipate an even split between AuAu and 500GeV
pp running:
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Considering how useful ~1-2 weeks of U+U running
would be
Run-12:
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pp – commissioning/physics with muon trigger and VTX
AuAu – first physics running with VTX
Additional physics running at 500GeV
HI running with VTX and FVTX
Will ask for some pp low energy running (HI
comparison – 62.4, 39, 22.4 GeV)
Some AuAu low energy running
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Excitation of constituent quark scaling (~20GeV)
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Run-11 Spin Goals and Assumptions
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PHENIX wants to emphasize that 500GeV
polarized running in Run-11 is commissioning for
both the collider and PHENIX
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New PHENIX Muon Trigger
New VTX detector
Assuming ~10 weeks of 500 GeV running, this
should be broken into two parts:
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First ~4 weeks: Collider commissioning, detector setup
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Expect priority is on luminosity and polarization
development, beam for experiments on evenings
Next 4-5 weeks: Physics running for W AL
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Emphasis on stable running conditions
PHENIX assumes it will integrate ~50pb-1
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Run-11 Expectation AL W->m
Assumes 50pb-1, P=50%
S/B=0.3 – Believe we can
ultimately achieve
S/B=3.0, but this requires
additional analysis and
development
S/B uncertainty shown as
gray box
Run-11 is the beginning of
the W physics program…
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PHENIX Near-Term Spin Goals
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Main PHENIX focus is W physics!
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Need to insure we accumulate sufficient integrated
luminosity
Expect to run at least three years
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Run-11 through Run-13?
Additional spin physics efforts:
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Longitudinal (500GeV):
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ALL for p0, h, charm, direct photons
Transverse (depends on running):
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IFF, AN for charm
Could be 200GeV (HI comparison running)
Particle correlations over a range of rapidities
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Long-Term HI Physics Objectives
Hot QCD Medium
q: fast color triplet
Jets and Leading Hadrons
q: fast color octet
C: slow color octet
B: slower color octet
Heavy Flavor
QQ: slow color
singlet/octet
J/y and Upsilons
QQ: fast color
singlet/octet
Photon: colorless
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High pT J/y
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How to Upgrade PHENIX?
Step #1: Remove the outer PHENIX Central Arms
Step #2: Replace Axial Field Magnet with Solenoid
(2 Tesla with inner radius = ~70 cm).
Step #3: New silicon tracking layers at 40 and 60 cm
Step #4: Compact EmCal (Silicon/Tungsten) |h|<1.0
8 cm total depth and preshower layer
Step #5: Hadronic Calorimeter Outside Magnet
Step #6: Maintain high DAQ bandwidth and triggers
Result 
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PHENIX Reborn
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sPHENIX? sPHNX?
A complete redesign of PHENIX focused on the
next generation of physics questions at RHIC.
145cm
80cm
HCAL
EMCAL
68cm
Preshower
IP
60cm
2T Solenoid
Silicon Tracker
VTX + 1 layer
Silicon Tracker
FVTX
1.2 < h < 2.7
8o < q < 37o
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GEANT4 Performance Evaluation
Excellent electron-ID for
pT > 2 GeV
electrons E= 5 GeV
Need detailed study at
lower pT as well.
g/p0 separation over
full kinematics > 50 GeV
p0
E=40 GeV
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p+
E= 5 GeV
Energy Resolution
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FastJet (anti-kT)
FastJet (anti-kT)
Jet Reconstruction
Mike McCumber (Colorado)
With tracking, dominated by “fakes” above some pT (e.g. pT > 10 GeV). Thus, low overall
efficiency for true high energy jets.
Bias in spectra reconstruction when FF is uncertain.
Issue largely solved with EMCal + HCal for jet energy!
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Forward Physics Objectives
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Transverse spin phenomena
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Kinematics high xf, high rapidity |h| > 2
Drell-Yan test QCD prediction for Sivers between SIDIS and DY
Separate Sivers and Collins and do a flavor separation for the
PDFs
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Longitudinal spin phenomena
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high rapidity |h| > 2  extend x coverage for DG and Dq
Drell-Yan in dAu
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p0-jet, g – jet, IFF for identified hadrons,
jet AN, direct photon
Measure quark distributions in nuclei
Possible access to quark saturation
EIC physics
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Measure polarized and unpolarized inclusive structure functions
in ep / eA (F2, FL, F3, g1, g2, g5)
“Diffractive physics” (DVCS, etc.)
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What is Required?
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All measurements need increased acceptance in
the forward direction (|h|>2) than the current
muon arms provide
Apart from DY all the measurements require EM
calorimetry and PID
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DY can be done with muons and/or electrons  so no
disadvantage
Hadronic calorimetry required for
Transversity+Collins (similar jet reconstruction
issues as Central PHENIX)
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Scenario I: DY at High h
3.1 < | h | < 3.9
2.5o < Q < 5.2o
Muon Arms 1.2 < | h | < 2.4
South:
12o < Q < 37o
North:
10o < Q < 37o
Central Arms
| h | < 0.35
60o < Q < 110o
MPC
Keep South Muon arm and put
m-detectors in the gap between
MuTr/MuID.
May require dipole magnet before
muon piston iron.
Upgraded FVTX required to cover
acceptance.
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Scenario I Pros and Cons
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Advantage:
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Modest upgrade
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Cost if no magnet is needed around ~2-3M$
Many technologies available  RPC
If additional magnet is needed modifications become
significantly more involved  higher costs ~5M$
Disadvantage:
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Very limited physics capabilities
Only possible in south muon arm (no gap in north
muon arm)
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Scenario II: Full Forward
Spectrometer
North Muon Arm
145cm
80cm
HCAL
EM
CAL
HCAL
EMCAL
Preshower
R
I
C
68cm
60cm
IP
Silicon Tracker
VTX + 1 layer
Silicon Tracker
FVTX
1.2 < h < 2.7
8o < q < 37o
H
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Scenario II: Pros and Cons
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Advantages:
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Can address all the physics objectives
Will keep the PHENIX spin community interested
Will be able to participate in EIC
EMCal could re-use currently existing PHENIX central arm EMCal
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HCal could try to re-use an HCal from an other experiment or use the same
technology as in central detector ~?M$
RICH
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COMPASS or LHC-b design ~4M$
Additional Tracking:
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new electronics needed ~2M$
GEM tracker?  less mass than Si-trackers
Improve STAR design: Cost ~3M$
Total Cost in the order of 12M$
Disadvantage:
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Relatively high cost
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ep/eA Physics
Lets concentrate on 4GeV lepton energy
 electron beam “replaces” yellow hadron beam
Proton Energy
50 GeV
100 GeV
250 GeV
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p/A
180o
pe: 1-2 GeV
pe: 2-3 GeV
pe: 3-4 GeV
4x50
pe: 0-1 GeV
0o
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e-
DIS vs. Diffractive (Hadrons)
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4x50
4x100
4x250
4x50
4x100
4x250
E.C. Aschenauer
RHIC
Spin& Collaboration
PheniX
STAR meet EICMeeting
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Diffractive Kinematics (p’)
t=(p4-p2)2 = 2[(mpin.mpout)-(EinEout - pzinpzout)]
4 x 50
Diffraction:
?
4 x 50
4 x 250
Roman pots
required to
detected outgoing
proton
4 x 100
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Conclusions
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The future of RHIC will require a bold effort to
directly address fundamental questions in QCD:
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Heavy Ions:
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Spin:
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Separation of Sivers and Collins+Transversity
DY to test modified universality
ep/eA:
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Quantitative study of the QGP
Inclusive and diffractive measurements to get us on the road
to the full EIC
PHENIX is developing a comprehensive upgrade
plan to pursue an exciting, broad physics
program over the next decade at RHIC!
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BACKUP
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FOCAL Acceptance
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h = 1.2-2.7 (red circle)
 = 0.27 p (x 2)
h = 1.6-2.7 (blue circle)
 = 2p
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Counts per 2.5 GeV bin in 50B AuAu Events
NLO pQCD (W. Vogelsang)
CTEQ6M5, DSS FF
pp @ 200 GeV |h|<1.0
p0
q,g jets
Direct g
Fragmentation g
0
p (assume RAA = 0.2)
Photons
Jets
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RHIC-II Luminosity Projections
SuperDAQ
(i.e. sDAQ)
DAQ2010
RHIC II luminosity and new proposed DAQ upgrades can
yield 50 billion AuAu event samples
(and with great new detector capabilities).
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