Marzia Rosati
mrosati@iastate.edu
Iowa State University
Marzia Rosati - ISU
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 Why Heavy Ion Collisions?
 QCD and the QGP Phase Transition
 Quarkonium in Media Measurements at the SPS
 New Quarkonium Measurements at RHIC
 Future Prospects at RHIC and LHC
Marzia Rosati - ISU
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II
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Relativistic Heavy Ion Collider
Brookhaven National
Laboratory
 3.83 km circumference
 Two independent rings
 120 bunches/ring
 106 ns crossing time
 Capable of colliding
~any nuclear species
on
~any other species
Z
s  (500 GeV )
A
 Energy up to:
 200 GeV for Au-Au
(per N-N collision)
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RHIC Experiments
Constraints on design
 High multiplicity events
 High rate needed
 Low-cost required
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Choices made
 Two large, flexible (& expensive!)
experiments
 Two small, optimized (&
inexpensive!) experiments
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RHIC Capabilities
 Nucleus-nucleus (AA) collisions up to sNN = 200 GeV
 Polarized proton-proton (pp) collisions up to sNN = 450
GeV
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How is RHIC Different?
 It’s a collider
Detector systematics independent of ECM
 It’s dedicated
Heavy ions will run 20-30 weeks/year
 It’s high energy
Access to perturbative phenomena
Jets
Non-linear dE/dx
 Its detectors are comprehensive
~All final state species measured with a suite of detectors
that nonetheless have significant overlap for comparisons
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RHIC and SPS comparison
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Charmonium at RHIC experimental Plan
 To establish that the observed charmonium suppression
pattern results from QGP:
 Study vs. pT
 Study vs. centrality
 Study in lighter systems
 Study vs. a control a vector meson that should not be suppressed, the
Upsilon
RHIC
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Brazil
China
University of São Paulo, São Paulo
Academia Sinica, Taipei, Taiwan
China Institute of Atomic Energy, Beijing
Peking University, Beijing
France
LPC, University de Clermont-Ferrand, Clermont-Ferrand
Dapnia, CEA Saclay, Gif-sur-Yvette
IPN-Orsay, Universite Paris Sud, CNRS-IN2P3, Orsay
LLR, Ecòle Polytechnique, CNRS-IN2P3, Palaiseau
SUBATECH, Ecòle des Mines at Nantes, Nantes
Germany University of Münster, Münster
Hungary Central Research Institute for Physics (KFKI), Budapest
Debrecen University, Debrecen
Eötvös Loránd University (ELTE), Budapest
India
Banaras Hindu University, Banaras
Bhabha Atomic Research Centre, Bombay
Israel
Weizmann Institute, Rehovot
Japan
Center for Nuclear Study, University of Tokyo, Tokyo
Hiroshima University, Higashi-Hiroshima
KEK, Institute for High Energy Physics, Tsukuba
Kyoto University, Kyoto
Nagasaki Institute of Applied Science, Nagasaki
RIKEN, Institute for Physical and Chemical Research, Wako
RIKEN-BNL Research Center, Upton, NY
Rikkyo University, Tokyo, Japan
Tokyo Institute of Technology, Tokyo
University of Tsukuba, Tsukuba
Waseda University, Tokyo
S. Korea Cyclotron Application Laboratory, KAERI, Seoul
Kangnung National University, Kangnung
Korea University, Seoul
Myong Ji University, Yongin City
System Electronics Laboratory, Seoul Nat. University, Seoul
Yonsei University, Seoul
Russia
Institute of High Energy Physics, Protovino
Joint Institute for Nuclear Research, Dubna
Kurchatov Institute, Moscow
PNPI, St. Petersburg Nuclear Physics Institute, St. Petersburg
St. Petersburg State Technical University, St. Petersburg
Sweden Lund University, Lund
12 Countries; 58 Institutions; 480 Participants*
*as of January
Marzia Rosati - ISU
USA Abilene Christian University, Abilene, TX
Brookhaven National Laboratory, Upton, NY
University of California - Riverside, Riverside, CA
University of Colorado, Boulder, CO
Columbia University, Nevis Laboratories, Irvington, NY
Florida State University, Tallahassee, FL
Florida Technical University, Melbourne, FL
Georgia State University, Atlanta, GA
University of Illinois Urbana Champaign, Urbana-Champaign, IL
Iowa State University and Ames Laboratory, Ames, IA
Los Alamos National Laboratory, Los Alamos, NM
Lawrence Livermore National Laboratory, Livermore, CA
University of New Mexico, Albuquerque, NM
New Mexico State University, Las Cruces, NM
Dept. of Chemistry, Stony Brook Univ., Stony Brook, NY
Dept. Phys. and Astronomy, Stony Brook Univ., Stony Brook, NY
Oak Ridge National Laboratory, Oak Ridge, TN
2004 University of Tennessee, Knoxville, TN
Vanderbilt University, Nashville, TN
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PHENIX Detector
West
3 global detectors (centrality)
2 central
spectrometers
J/yee
South
East
North
2 forward
spectrometers
J/ymm
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 3 global
detectors
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Muon Measurement in PHENIX
 1.2 < h < 2.4 (north), 1.2 < h < 2.2 (south), full f coverage
 tracking with 3 stations of
chambers in magnetic
field
 muon ID with 5 layers of
steel absorber and Iarocci
tubes
 low energy cutoff at 2
GeV/c
PHENIX with 2 forward arms
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Virtual Tour of PHENIX Central Arms
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Electron Measurement in PHENIX
Run1
Electrons
 - 0.35 < h < 0.35, df = p/2  2
0.8GeV<p<0.9GeV
 charged particle tracking
 DC / PC / TEC
 hadron rejection at
level
in Au+Au central collisions
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All charged
With RICH hit
 RICH / EMCal / TEC
 good momentum resolution
E/p ratio
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PHENIX p Mis-identification
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Charmonium in Central & Forward Arms
 simultaneous access to regions with different energy
densities
rapidity density of produced particles as a measure
good test if suppression is a function of local energy
density
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Charmonium Measurement in PHENIX
Year
2000
2001
2002
2002
Ions
sNN
Luminosity
Detectors
J/
Au-Au
130 GeV
1 mb-1
Central (electrons)
0
Au-Au
200 GeV
24 mb-1
p-p
200 GeV
0.15 pb-1
d-Au
200 GeV
2.74 nb-1
p-p
200 GeV
0.35
pb-1
Au-Au
200 GeV
62 GeV
~240 ub-1
~9 ub-1
2003
2004
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Central
+ 1 muon arm
Central
13 + 0
46 + 66
300+1400
+ 2 muon arms
100+420
Central
+ 2 muon arms
?
?
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PHENIX: J/e+e- and m+m- from pp
s= 3.99 +/- 0.61(stat) +/- 0.58(sys) +/- 0.40(abs) mb
(BR*stot = 239 nb)
Central and forward rapidity measurements
from Central and Muon Arms:
•Rapidity shape consistent with various PDFs
•√s dependence consistent with various PDFs
with factorization and renormalization scales
chosen to match data
Higher statistics needed to constrain PDFs
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PHENIX: J/ in dA
South Muon Arm
North Muon Arm
Eskola, Kolhinen, Vogt hep-ph/0104124
d
PHENIX μ, North
PHENIX m, SOUTH
Au
Central Arm
PHENIX e
•PHENIX measurements cover expected shadowing, antishadowing range
•All expected to see pT broadening
•dE/dx not expected to be significant effect at RHIC energies
•Overall absorption expected
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J/ dA from PHENIX
d
Au
•Suppression in deuteron direction consistent with some shadowing but
can’t distinguish among various models
•Anti-shadowing in Au direction
•Overall absorption
*Centrality dependence unique measurement from RHIC
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ee Invariant Mass Spectra in Au-Au
Seven different mass fitting and counting
methods used to determine systematic error
in the number of counts.
NJ/ = 10.8 + 3.2 (stat) + 3.8 - 2.8 (sys)
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PHENIX: J/ in AuAu from Run 2
R. L. Thews, M. Schroedter, J. Rafelski,
Phys Rev C 63, 054905
Plasma Coalescence Model
Binary Scaling
Absorption (Nuclear + QGP) + final-state
coalescence
Absorption (Nuclear + QGP)
L. Grandchamp, R. Rapp, Nucl Phys
A709, 415; Phys Lett B 523, 60
•49.3 million minimum bias events analyzed in Central Arm, Run 2
•8, 5, 0 “most likely signal” for 3 centrality bins
•Not enough statistical significance to distinguish various models but strong
enhancement seems to be disfavored.
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In the future
 Full exploration of J/
production
versus “Nbinary” ~ A(b)*A(b)
via
A long run with Au-Au
A series of shorter light ion
runs
 p-A or d-A running
Log10(Nbinary)
Species
OO
SiSi
CuCu
II
AuAu
Marzia Rosati - ISU
Number of J/ 's
(0.6 R.Y. - AuAu,
0.1 R.Y. - others)
1.15E+05
1.44E+05
1.56E+05
1.73E+05
1.79E+05
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PHENIX Upgrade
 Ultimately we want to
detect open charm
“directly” via displaced
vertices
 Development of required
Si tracking for PHENIX
well underway
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STAR Electron Measurement
 - 1 < h < 1, df = 2p
 Particle Identification
EMCAL, dE/dx in SVT and TPC
Magnet
Coils
Time Projection
Chamber
Silicon Vertex
Tracker
ZCal
Barrel EM
Calorimeter
ZCal
Central Trigger Barrel
RICH
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 J/y is accepted if both
electrons P>1.5GeV/c and
fall into the EMC
 40K J/y for 1 year of
running at full luminosity
with
signal/background=1:3
Detector Acceptance
Charmonium Measurement in STAR
y
pT
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RHIC-II
RHIC-II:
L = 5·1032 cm-2 s-1 (pp)
L = 7-9·1027 cm-2 s-1 = 7-9 mb-1 s-1 (AuAu)
hadr. min bias: 7200 mb 8 mb-1 s-1 = 58 kHz
30 weeks, 50% efficiency  Ldt = 80 nb-1
100% reconstruction efficiency
Assume here: sAA = spp (AB)a
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Rates at RHIC-II
 Au+Au min bias production rates
 R(J/) = 27 Hz
 R(’) = 1 Hz
 R((1S)) = 0.01701 Hz
 R((2S)) = 0.00297 Hz
 R((3S)) = 0.00324 Hz
 Au+Au, 30 weeks, 50% efficiency produced number of events
 2.7·108 J/
 1·107 ’
 170100 (1S)
 29700 (2S)
 32400 (3S)
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energy density
e/T4
In the Future
Going to even higher energy
SPS
RHIC
QGP
LHC
AGS
hadron gas
TC ~ 170 MeV
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LHC Heavy Ions
ALICE e+e-
ALICE μ+μ-
CMS
ATLAS
J/y
2.1x104
8.0x105
3.7x104
2.5x104

1.4x104
5.0x103
2.6x104
2.1x104
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Saturation Physics
The ratio of the EKS98 corrected
nuclear gluon distribution to
CTEQ5L
overlapping color sources lead
to the saturation of the gluon
phase space in the initial
state nuclear wavefunction
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x coverage
Coverage over 5
decades in x for which
nuclear effects in the
gluon density are
expected to manifest
The ratio of the EKS98
corrected nuclear gluon
distribution to CTEQ5L
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Summary
 The good and bad news: the phenomenology of charmonium in
nuclear collisions is richer than anyone supposed
 There is enough interesting physics to keep us busy
 Things are not as simple as first supposed
 The goal of the field has shifted from “discovering the quark-gluon
plasma” to “characterizing the nuclear medium under extreme
conditions”
 This is a plus – we’ve moved past presupposing how things will
behave and towards measuring and understanding what really
happens
 Charmonium is a critical probe in this wider effort
 RHIC data in Au+Au collisions is right around the corner
 Experimental program will continue at LHC
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