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26-Oct-07 W.A. Zajc
Introductionand
Welcome
AdS/CFT Intersects Nuclear Beams at Columbia
W.A. ZajcColumbia University
26-Oct-07 W.A. Zajc
RHIC Perspectives
W.A. ZajcColumbia University
RHIC Perspectives
W.A. ZajcColumbia University
26-Oct-07 W.A. Zajc
Really, It’s A Meta-Talk
Introduction, Motivation,Definition of terms up to here
Two major discoveries:FlowJet quenching
26-Oct-07 W.A. Zajc
Really, It’s A Meta-Talk
Jet quenching,away-side disappearance,direct photons
Mach cones, re-appearance of the away side
26-Oct-07 W.A. Zajc
The Primacy of QCD� While the (conjectured) bound
is a purely quantum mechanical result . . .
�It was derived in and motivated by the Anti-de Sitter space / Conformal Field Theory c orrespondence
� Weak form:� “Four-dimensional N=4 supersymmetric SU(N c) gauge theory is equivalent
to IIB string theory with AdS 5 x S5 boundary conditions.”( The Large N limit of superconformal field theories a nd supergravity ,
J. Maldacena, Adv. Theor. Math. Phys. 2, 231, 1998 hep-th/9711200 )
� Strong form:� “Hidden within every non-Abelian gauge theory, even within the weak
and strong nuclear interactions, is a theory of qua ntum gravity.”( Gauge/gravity duality , G.T. Horowitz and J. Polchinski, gr-qc/0602037 )
� Strongest form: Only with QCD can we explore experimentally these fascinating connections over the full range of the coupling constant to study QGP
πη
4
h≥s
≡≡≡≡ Quantum Gauge Phluid
26-Oct-07 W.A. Zajc
The (Assumed) Connection� Exploit Maldacena’s
“D-dimensional strongly coupled gauge theory ⇔⇔⇔⇔ (D+1)-dimensional stringy gravity”
� Thermalize with massive black brane
� Calculate viscosity ηηηη = “Area”/16 ππππG
� Normalize by entropy (density) s = “Area” / 4G
� Dividing out the infinite “areas” :
� Conjectured to be a lower bound “ for all relativistic quantum field theories at finite temperature and zero chemical po tential ”.
� See “ Viscosity in strongly interacting quantum field the ories from black hole physics ”, P. Kovtun, D.T. Son, A.O. Starinets, Phys.Rev.Lett.94:111601, 2005, hep-th/0405231
Infinite “Area” !
πη
4
1)(
ks
h=
hµν
Aµ
Aν
26-Oct-07 W.A. Zajc
New Dimensions in RHIC Physics� “ The stress tensor of a quark moving through N=4 thermal
plasma”, J.J. Friess et al ., hep-th/0607022
Our 4Our 4 --d d worldworld
String String theorist’s theorist’s
5+55+5--d d worldworld
The stuff formerly The stuff formerly known as QGPknown as QGP
Heavy quark Heavy quark moving moving through through
the the mediummediumEnergy loss Energy loss
from string from string dragdrag
Jet modifications Jet modifications from wake fieldfrom wake field
26-Oct-07 W.A. Zajc
Measuring η/s� Damping (flow, fluctuations, heavy quark motion) ~ ηηηη/s
� FLOW: Has the QCD Critical Point Been Signaled by Observations at RHIC?,R. Lacey et al., Phys.Rev.Lett.98:092301,2007 (nucl-ex/0609025)
� The Centrality dependence of Elliptic flow, the Hydrodynamic Limit, and the Viscosity of Hot QCD, H.-J. Drescher et al., (arXiv:0704.3553)
� FLUCTUATIONS: Measuring Shear Viscosity Using Transverse Momentum Correlations in Relativistic Nuclear Collisions, S. Gavin and M. Abdel-Aziz, Phys.Rev.Lett.97:162302,2006 (nucl-th/0606061)
� DRAG, FLOW: Energy Loss and Flow of Heavy Quarks in Au+Au Collisions at √sNN = 200 GeV (PHENIX Collaboration), A. Adare et al., to appear in Phys. Rev. Lett. (nucl-ex/0611018)
ππππηηηη
4
1)2.12.01.1( ±±±±±±±±====
s
ππππηηηη
4
1)8.30.1( −−−−====�
ππππηηηη
4
1)0.23.1( −−−−====�
ππππηηηη
4
1)5.29.1( −−−−====
s
CHARM!
26-Oct-07 W.A. Zajc
Has the QCD Critical Point Been Signaled by Observa tions at RHIC?,R. Lacey et al ., Phys.Rev.Lett.98:092301,2007 ( nucl-ex/0609025 )� Signature: FLOW� Calculation:
� Payoff Plot:
ππππηηηη
λλλλ
λλλληηηη
4
1)2.12.01.1(
fm03.03.0
05.035.0
MeV3165
~
±±±±±±±±====⇒⇒⇒⇒
±±±±====±±±±====
±±±±====
s
c
T
cTs
f
s
sf
Fit v2 ~I1(w)/I0(w); w = mT/2T
On-shell transport model for gluons, Z. Xu and C. Greiner, hep-ph/0406278.
PHENIX v2/ε data (nucl-ex/0608033) compared to R.S. Bhalerao et al. (nucl-th/0508009)
26-Oct-07 W.A. Zajc
Measuring Shear Viscosity Using Transverse Momentum Correlations in Relativistic Nuclear Collisions, S. Gavin and M. Abdel-Aziz, Phys.Rev.Lett.97:162302,2006 (nucl-th/0606061)
� Signature: FLUCTUATIONS� Calculation:
� Payoff Plot: ππππηηηη
ττττττττ
ττττττττηηηησσσσσσσσ
ττττττττττττ
ττττηηηησσσσσσσσ
ηηηη
4
1)8.31(
fm20~,fm1~
114
14
0
,,
22
0
020
2
2
−−−−====⇒⇒⇒⇒
−−−−====−−−−
−−−−====−−−−
====
∇∇∇∇−−−−∂∂∂∂∂∂∂∂
s
sT
sT
gsTt
CfPf
CfPfpc
f
f
Diffusion eq. for fluctuations g
Compare to STAR data on centrality dependence of rapidity width σ of pT fluctuations
Difference in correlation widths for central and peripheral collisions
26-Oct-07 W.A. Zajc
The Centrality dependence of Elliptic flow, the Hyd rodynamic Limit, and the Viscosity of Hot QCD , H.-J. Drescher et al ., (arXiv:0704.3553 )� Signature: FLOW� Calculation:
� Payoff Plot:
ππππηηηη
σσσσηηηη
εεεεεεεε
σσσσττττσσσσττττ
ρσρσρσρσλλλλ
4
1)5.29.1(
4,/264.1,31/,7.0
/1
1
)(111
0
0
22
−−−−====⇒⇒⇒⇒
================
++++
====
====
========≡≡≡≡
s
nsTcK
KKvv
cdydN
Ac
dydN
AR
RK
S
perfect
SS
Knudsen number K
Fits to PHOBOS v2 data to determine σ for Glauber and CGC initial conditions
Decrease in flow due to finite size
26-Oct-07 W.A. Zajc
Moore and Teaney Phys.Rev.C71:064904,2005(perturbative, argue ~valid non-perturbatively)
Energy Loss and Flow of Heavy Quarks in Au+Au Colli sions at √sNN = 200 GeV (PHENIX Collaboration), A. Adare et al ., Phys. Rev. Lett. 98:172301,2007 ( nucl-ex/0611018 )
� Signature: FLOW, ENERGY LOSS� Calculation:
� Payoff Plot:
(((( ))))
ππππηηηη
εεεεηηηηππππ
4
1)0.23.1(
3for6~)/(/
2)64(~
−−−−====⇒⇒⇒⇒
====++++
−−−−
s
NPD
TD
fHQ
HQ
Rapp and van HeesPhys.Rev.C71:034907,2005, to fit both PHENIX v2(e) and RAA(e)
26-Oct-07 W.A. Zajc
(Some) Things I’d Like To Know
� Are there better ways to extract η/s ?
� Can these existing estimates be improved ?� (In particular, can systematic errors be understood?)
� All of these methods rely on εεεε+P = Ts . �How does this change in the presence of a conserved charge
?
� In ordinary fluids, η/s has a pronounced minimum near the critical point.
�Can AdS/CFT say anything about this for gauge fluids?
26-Oct-07 W.A. Zajc
(More) Things I’d Like To Know
� Are AdS/CFT predictions falsifiable ? � What if Song and Heinz η/s < 1/4π is correct?
� Suppression of elliptic flow in a minimally viscous quark-gluon plasma, H. Song and U. Heinz, arXiv:0709.0742v1 .
� What if Mach cone angles different from data ?
� What if 1/√γγγγ not seen in J/Ψ suppression ?
� What data can best constrain initial conditions?� (Will we ever be able to eliminate this source of ambiguity
between Glauber, CGC, … ?)
� Are there AdS/CFT setups to do elliptic flow dynamically?�Can they say anything about the observed scaling ?
26-Oct-07 W.A. Zajc
The “Flow” Is Perfect� The “fine structure” v 2(pT) for different mass particles
shows good agreement with ideal (“perfect fluid”) hydrodynamics
� Roughly: ∂ννννTµνµνµνµν =0 →→→→ Work-energy theorem →→→→ ∫∫∫∫ ∇∇∇∇P d(vol) = ∆∆∆∆EK ≅≅≅≅ mT – m0 ≡≡≡≡
∆∆∆∆KET
~~
22TT pmKE +≡
26-Oct-07 W.A. Zajc
The “Flow” Knows Quarks� The “fine structure” v 2(pT) for different mass particles
shows good agreement with ideal (“perfect fluid”) hydrodynamics
� Scaling flow parameters by quark content n q resolves meson-baryon separation of final state hadrons
baryonsbaryons
mesonsmesons
26-Oct-07 W.A. Zajc
(More) Things I’d Like To Know� What does flow scaling tell us about degrees of freedom?
� Hadronic Modes and Quark Properties in the Quark-Gluon Plasma,M. Mannarelli and R. Rapp, arXiv:hep-ph/0505080v2 :m ~ 150 MeV , Γ ~ 200 MeV .
�Is any form of quasiparticle consistent with KSS bound?
� All(?) AdS/CFT calculations find drag ~ √λλλλ = √g2NC .
� What is this telling us about the degrees of freedom ?
� Is there a unique prescription for fixing coupling ?� Is there well-controlled expansion away from ‘t Hooft limit?� Calibrate it with lattice ‘data’ ?�ASIDE: Those who most often pronounce “AdS/CFT is useless because
the coupling doesn’t run” are those most likely to do calculations with αs = 0.5 .
26-Oct-07 W.A. Zajc
(Big ) Things I’d Like To Know
� Can one start from confining, chiral Sakai-Sugimoto and push it through a phase transition ?
� Hod tells us τ > 1 / π T. � Universal Bound on Dynamical Relaxation Times and B lack-Hole
Quasinormal Ringing , S. Hod, arXiv:gr-qc/0611004v1
�Can AdS/CFT address this ?
� What does it mean to have a gravity dual ?�In particular, how do I find it ?
�What is the impact of the KSS conjecture on other fields ?
26-Oct-07 W.A. Zajc
Working Title: The Fluid Nature of QGP
� From the Oxford English Dictionary:1) Primary definition: (adj.) fluid :
"Having the property of flowing; consisting of particles that move freely among themselves, so as to give way before the slightest pressure. (A general term including both gaseous and liquid substances.)”
2) Secondary definition: (adj.)"Flowing or moving readily; not solid or rigid; not fixed, firm, or stable.”
� SUMMARY: Followinga) a discovery period, during which time our understanding of “quark-gluon plasma” was fluid(2), and b) a paradigm shift,we are now developing a solid understanding of the extraordinary fluid(1) produced at RHIC.
26-Oct-07 W.A. Zajc
Expectations circa 2000
As encoded in the Nuclear Physics Wall Chart,
http://www.lbl.gov/abc/wallchart/
RHIC would create a quark-gluon plasma;
a “gas” of weakly interacting
quarks and gluons
26-Oct-07 W.A. Zajc
The Plan circa 2000� Use RHIC’s unprecedented capabilities
� Large √s �����Access to reliable pQCD probes�Clear separation of valence baryon number and glue�To provide definitive experimental evidence for/aga inst
Quark Gluon Plasma (QGP)
� Polarized p+p collisions
� Two small detectors, two large detectors� Complementary capabilities� Small detectors envisioned to have 3-5 year lifetim e� Large detectors ~ facilities
�Major capital investments�Longer lifetimes�Potential for upgrades in response to discoveries
See earlier talk by M. Grosse Perdekamp
26-Oct-07 W.A. Zajc
Since Then…� Accelerator complex
� Routine operation at 2-4 x design luminosity (Au+Au )� Extraordinary variety of operational modes
� Species: Au+Au, d+Au, Cu+Cu, p ↑↑↑↑+p↑↑↑↑� Energies: 22 GeV (Au+Au, Cu+Cu, p ↑↑↑↑), 56 GeV (Au+Au),
62 GeV (Au+Au,Cu+Cu, p ↑↑↑↑+p↑↑↑↑) , 130 GeV (Au+Au), 200 GeV (Au+Au, Cu+Cu, d+Au, p ↑↑↑↑+p↑↑↑↑), 410 GeV (p↑↑↑↑), 500 GeV (p↑↑↑↑)
� Experiments: � Worked !
� Science� >160 refereed publications, among them > 90 PRL’s� Major discoveries
� Future� Demonstrated ability to upgrade� Key science questions identified� Accelerator and experimental upgrade program
underway to perform that science
26-Oct-07 W.A. Zajc
ApproachWill present sample of results from various points of the collision process:
1. Final State
Yields of produced particles
Thermalization, Hadrochemistry
2. Initial State
Hydrodynamic flow from
initial spatial asymmetries
3. Probes of dense matter
26-Oct-07 W.A. Zajc
Assertion� In these complicated events, we have
(a posteriori ) control over the event geometry:
� Degree of overlap
� Orientation with respect to overlap
Reaction
Reaction
PlanePlane
““ Central”Central” ““ Peripheral”Peripheral”
26-Oct-07 W.A. Zajc
Language
� We all have in common basic nuclear properties
� A, Z …
� But specific to heavy ion physics
� v2
�RAA
� T� µµµµB
� ηηηη� s
1 if yield = perturbative value from initial parton -parton flux
Fourier coefficient of azimuthal anisotropies ���� “flow”
Temperature ( MeV)
Baryon chemical potential ( MeV) ~ net baryon density
Viscosity ( MeV 3 )
Entropy density ( MeV 3 ) ~ “particle” density
26-Oct-07 W.A. Zajc
Final StateDoes the huge abundance of final state particles reflect a thermal distribution?:
1. Final State
Yields of produced particles
Thermalization, Hadrochemistry
Consistent with thermal production
T ~ 170 MeV , µµµµB ~ 30 MeV
26-Oct-07 W.A. Zajc
RHIC’s Two Major Discoveries� Discovery of
strong “elliptic” flow:� Elliptic flow in Au + Au collisions at √sNN= 130 GeV, STAR Collaboration, ( K.H. Ackermann et al. ). Phys.Rev.Lett.86:402-407,2001
� 318 citations
� Discovery of “jet quenching”� Suppression of hadrons with large
transverse momentum in central Au+Au collisions at √sNN = 130 GeV, PHENIX Collaboration ( K. Adcox et al.), Phys.Rev.Lett.88:022301,2002
� 384 citations
26-Oct-07 W.A. Zajc
Initial StateHow are the initial state densities and asymmetries imprinted on the detected distributions?
3. Initial State
Hydrodynamic flow from
initial spatial asymmetries
26-Oct-07 W.A. Zajc
Motion Is Hydrodynamic
x
yz
� When does thermalization occur? � Strong evidence that final state bulk behavior
reflects the initial state geometry
� Because the initial azimuthal asymmetrypersists in the final statedn/d φφφφ ~ 1 + 2 v2(pT) cos (2 φφφφ) + ...
2v2
26-Oct-07 W.A. Zajc
The “Flow” Is Perfect� The “fine structure” v 2(pT) for different mass particles
shows good agreement with ideal (“perfect fluid”) hydrodynamics
� Roughly: ∂ννννTµνµνµνµν =0 →→→→ Work-energy theorem →→→→ ∫∫∫∫ ∇∇∇∇P d(vol) = ∆∆∆∆EK ≅≅≅≅ mT – m0 ≡≡≡≡
∆∆∆∆KET
~~
22TT pmKE +≡
26-Oct-07 W.A. Zajc
The “Flow” Knows Quarks� The “fine structure” v 2(pT) for different mass particles
shows good agreement with ideal (“perfect fluid”) hydrodynamics
� Scaling flow parameters by quark content n q resolves meson-baryon separation of final state hadrons
baryonsbaryons
mesonsmesons
26-Oct-07 W.A. Zajc
Probes of Dense MatterQ. How dense is the matter?A. Do pQCD Rutherford scattering on deep interior u sing“auto-generated” probes:
2. Probes of dense matter
26-Oct-07 W.A. Zajc
Baseline p+p Measurements with pQCD� Consider measurement of ππππ0’s in p+p
collisions at RHIC.� Compare to pQCD calculation
� Phys. Rev. Lett. 91, 241803 (2003)
),(
)(
),(),(
2
22
/
//
µ
σ
µµσ
hch
bBbaAa
zD
dcbad
xfxfd
⊗
+→+⊗
⊗=
∧
•parton distribution functions, for partons a and b•measured in DIS, universality
•perturbative cross-section (NLO)•requires hard scale
•factorization between pdf and cross section
•fragmentation function•measured in e+e-
26-Oct-07 W.A. Zajc
Au+Au: Systematic Suppression Pattern
� ≈ constancy for pT > 4 GeV/c for all centralities?
Suppressed
Suppressed
Enh
ance
dE
nhan
ced
26-Oct-07 W.A. Zajc
The Matter is Opaque� STAR azimuthal
correlation function shows ~ complete absence of “away-side” jet
�Partner in hard scatter is completely absorbedin the dense medium
GONE
∆Φ∆Φ∆Φ∆Φ=0
∆Φ∆Φ∆Φ∆Φ
∆Φ ∆Φ ∆Φ ∆Φ = ππππ
∆Φ ∆Φ ∆Φ ∆Φ = 0000
26-Oct-07 W.A. Zajc
Schematically (Partons)Scattered partons on the “near side” lose energy ,
but emerge;
those on the “far side” are totally absorbed
26-Oct-07 W.A. Zajc
Control: Photons shine, Pions don’t
� Direct photons are not inhibited by hot/dense medium� Rather: shine through consistent with pQCD
26-Oct-07 W.A. Zajc
Schematically (Photons)Scattered partons on the “near side” lose energy ,
but emerge;
the direct photon always emerges
26-Oct-07 W.A. Zajc
� This one figure encodes rigorous control of systematics
� in four different measurements over many orders of magnitude
Precision Probes
centralNcoll = 975 ± 94
== ==
26-Oct-07 W.A. Zajc
Connecting Soft and Hard RegimesScattered partons on the “near side” lose energy ,
but emerge;
those on the “far side” are totally absorbed →→ Really ?Really ?
26-Oct-07 W.A. Zajc
� Mach cone?☑ Jets travel faster than the
speed of sound in the medium.
☑ While depositing energy via gluon radiation.
�QCD “sonic boom” (?)
�To be expectedin a dense fluidwhich is strongly-coupled
Fluid Effects on Jets ?
26-Oct-07 W.A. Zajc
High pT Parton → Low pT “Mach Cone”?� The “ disappearance ”
is that of the high p T partner
� But at low p T, see re-appearance
� and
� “Side-lobes”(Mach cones?)
26-Oct-07 W.A. Zajc
Suggestion of Mach Cone?� Modifications to di-jet hadron pair correlations in Au+Au collisions at √sNN = 200 GeV,
PHENIX Collaboration (S.S. Adler et al.), Phys.Rev.Lett.97:052301,2006
A “perfect”fluid response!
∆Φ∆Φ∆Φ∆Φ
26-Oct-07 W.A. Zajc
How Perfect is “Perfect” ?� All “realistic” hydrodynamic calculations for RHIC f luids to
date have assumed zero viscosity� η η η η = 0 ���� “perfect fluid”� But there is a (conjectured) quantum limit:
“ A Viscosity Bound Conjecture ”, P. Kovtun , D.T. Son, A.O. Starinets , hep-th/0405231
� Where do “ordinary”fluids sit wrtthis limit?
� RHIC “fluid” mightbe at ~1 on this scale (!)
T=10T=101212 KK
(( 44π)π)
sDensityEntropyππππππππ
ηηηη4
)(4
hh ≡≡≡≡≥≥≥≥
26-Oct-07 W.A. Zajc
� Remove your organic prejudices� Don’t equate viscous with “sticky” !
� Think instead of a not-quite-ideal fluid:� “not-quite-ideal” ≡≡≡≡ “supports a shear stress”� Viscosity ηηηη
then defined as
� Dimensional estimate:
� small viscosity ���� Large cross sections
�Large cross sections ���� strong couplings
�Strong couplings ���� perturbation theory difficult !
Viscosity Primer
yv
AF xx
∂∂∂∂∂∂∂∂−−−−==== ηηηη
σσ
1
)()(η
pn
pnmfppn
pathfreemeandensitymomentum
========≈≈≈≈
××××≈≈≈≈
26-Oct-07 W.A. Zajc
The Primacy of QCD� While the (conjectured) bound
is a purely quantum mechanical result . . .
�It was derived in and motivated by the Anti-de Sitter space / Conformal Field Theory c orrespondence
� Weak form:� “Four-dimensional N=4 supersymmetric SU(N c) gauge theory is equivalent
to IIB string theory with AdS 5 x S5 boundary conditions.”( The Large N limit of superconformal field theories a nd supergravity ,
J. Maldacena, Adv. Theor. Math. Phys. 2, 231, 1998 hep-th/9711200 )
� Strong form:� “Hidden within every non-Abelian gauge theory, even within the weak
and strong nuclear interactions, is a theory of qua ntum gravity.”( Gauge/gravity duality , G.T. Horowitz and J. Polchinski, gr-qc/0602037 )
� Strongest form: Only with QCD can we explore experimentally these fascinating connections over the full range of the coupling constant to study QGP
πη
4
h≥s
≡≡≡≡ Quantum Gauge Phluid
26-Oct-07 W.A. Zajc
The (Assumed) Connection� Exploit Maldacena’s
“D-dimensional strongly coupled gauge theory ⇔⇔⇔⇔ (D+1)-dimensional stringy gravity”
� Thermalize with massive black brane
� Calculate viscosity ηηηη = “Area”/16 ππππG
� Normalize by entropy (density) s = “Area” / 4G
� Dividing out the infinite “areas” :
� Conjectured to be a lower bound “ for all relativistic quantum field theories at finite temperature and zero chemical po tential ”.
� See “ Viscosity in strongly interacting quantum field the ories from black hole physics ”, P. Kovtun, D.T. Son, A.O. Starinets, Phys.Rev.Lett.94:111601, 2005, hep-th/0405231
Infinite “Area” !
πη
4
1)(
ks
h=
hµν
Aµ
Aν
See next talk: QGP- Theoretical Overview , U. Wiedemann
26-Oct-07 W.A. Zajc
New Dimensions in RHIC Physics� “ The stress tensor of a quark moving through N=4 thermal
plasma”, J.J. Friess et al ., hep-th/0607022
Our 4Our 4 --d d worldworld
String String theorist’s theorist’s
5+55+5--d d worldworld
The stuff formerly The stuff formerly known as QGPknown as QGP
Heavy quark Heavy quark moving moving through through
the the mediummediumEnergy loss Energy loss
from string from string dragdrag
Jet modifications Jet modifications from wake fieldfrom wake field
26-Oct-07 W.A. Zajc
Measuring η/s� Damping (flow, fluctuations, heavy quark motion) ~ ηηηη/s
� FLOW: Has the QCD Critical Point Been Signaled by Observations at RHIC?,R. Lacey et al., Phys.Rev.Lett.98:092301,2007 (nucl-ex/0609025)
� The Centrality dependence of Elliptic flow, the Hydrodynamic Limit, and the Viscosity of Hot QCD, H.-J. Drescher et al., (arXiv:0704.3553)
� FLUCTUATIONS: Measuring Shear Viscosity Using Transverse Momentum Correlations in Relativistic Nuclear Collisions, S. Gavin and M. Abdel-Aziz, Phys.Rev.Lett.97:162302,2006 (nucl-th/0606061)
� DRAG, FLOW: Energy Loss and Flow of Heavy Quarks in Au+Au Collisions at √sNN = 200 GeV (PHENIX Collaboration), A. Adare et al., to appear in Phys. Rev. Lett. (nucl-ex/0611018)
ππππηηηη
4
1)2.12.01.1( ±±±±±±±±====
s
ππππηηηη
4
1)8.30.1( −−−−====�
ππππηηηη
4
1)0.23.1( −−−−====�
ππππηηηη
4
1)5.29.1( −−−−====
s
CHARM!
26-Oct-07 W.A. Zajc
Has the QCD Critical Point Been Signaled by Observa tions at RHIC?,R. Lacey et al ., Phys.Rev.Lett.98:092301,2007 ( nucl-ex/0609025 )� Signature: FLOW� Calculation:
� Payoff Plot:
ππππηηηη
λλλλ
λλλληηηη
4
1)2.12.01.1(
fm03.03.0
05.035.0
MeV3165
~
±±±±±±±±====⇒⇒⇒⇒
±±±±====±±±±====
±±±±====
s
c
T
cTs
f
s
sf
Fit v2 ~I1(w)/I0(w); w = mT/2T
On-shell transport model for gluons, Z. Xu and C. Greiner, hep-ph/0406278.
PHENIX v2/ε data (nucl-ex/0608033) compared to R.S. Bhalerao et al. (nucl-th/0508009)
26-Oct-07 W.A. Zajc
Measuring Shear Viscosity Using Transverse Momentum Correlations in Relativistic Nuclear Collisions, S. Gavin and M. Abdel-Aziz, Phys.Rev.Lett.97:162302,2006 (nucl-th/0606061)
� Signature: FLUCTUATIONS� Calculation:
� Payoff Plot: ππππηηηη
ττττττττ
ττττττττηηηησσσσσσσσ
ττττττττττττ
ττττηηηησσσσσσσσ
ηηηη
4
1)8.31(
fm20~,fm1~
114
14
0
,,
22
0
020
2
2
−−−−====⇒⇒⇒⇒
−−−−====−−−−
−−−−====−−−−
====
∇∇∇∇−−−−∂∂∂∂∂∂∂∂
s
sT
sT
gsTt
CfPf
CfPfpc
f
f
Diffusion eq. for fluctuations g
Compare to STAR data on centrality dependence of rapidity width σ of pT fluctuations
Difference in correlation widths for central and peripheral collisions
26-Oct-07 W.A. Zajc
The Centrality dependence of Elliptic flow, the Hyd rodynamic Limit, and the Viscosity of Hot QCD , H.-J. Drescher et al ., (arXiv:0704.3553 )� Signature: FLOW� Calculation:
� Payoff Plot:
ππππηηηη
σσσσηηηη
εεεεεεεε
σσσσττττσσσσττττ
ρσρσρσρσλλλλ
4
1)5.29.1(
4,/264.1,31/,7.0
/1
1
)(111
0
0
22
−−−−====⇒⇒⇒⇒
================
++++
====
====
========≡≡≡≡
s
nsTcK
KKvv
cdydN
Ac
dydN
AR
RK
S
perfect
SS
Knudsen number K
Fits to PHOBOS v2 data to determine σ for Glauber and CGC initial conditions
Decrease in flow due to finite size
26-Oct-07 W.A. Zajc
Moore and Teaney Phys.Rev.C71:064904,2005(perturbative, argue ~valid non-perturbatively)
Energy Loss and Flow of Heavy Quarks in Au+Au Colli sions at √sNN = 200 GeV (PHENIX Collaboration), A. Adare et al ., Phys. Rev. Lett. 98:172301,2007 ( nucl-ex/0611018 )
� Signature: FLOW, ENERGY LOSS� Calculation:
� Payoff Plot:
(((( ))))
ππππηηηη
εεεεηηηηππππ
4
1)0.23.1(
3for6~)/(/
2)64(~
−−−−====⇒⇒⇒⇒
====++++
−−−−
s
NPD
TD
fHQ
HQ
Rapp and van HeesPhys.Rev.C71:034907,2005, to fit both PHENIX v2(e) and RAA(e)
26-Oct-07 W.A. Zajc
RHIC and the Phase “Transition”� The lattice tells us that collisions at RHIC map ou t the
interesting region from
� High T init~ 300 MeV
to
� Low T final~ 100 MeV
30
)( 2
4
πε =T
T
Recall per masslessdegree of freedom
?
26-Oct-07 W.A. Zajc
LHC� How could we not choose to investigate “QGP” at ever y
opportunity?� LHC offers unparalleled
increase in √s� Will this too create a
strongly-coupled fluid?
� Active pursuit via � Dedicated experiment (ALICE)� Targeted studies (CMS, ATLAS)
26-Oct-07 W.A. Zajc
RHIC
Physics for Many INPC’s To Come!
� Exploration� ~ Completed� Discovery!
� Characterization� Photon+Jet� Heavy Flavor� Energy Scans
� Exploitation(of upgrade potential)� Source � Detectors� Luminosity
RHIC →→→→ RHIC II
� Preparation�
�
�
� (Anticipation)� Exploration
� ~ Completed� Discovery!
� Characterization� Photon+Jet� Heavy Flavor� Energy Scans
Exploitation
LHC
� Preparation�
�
�
� (Anticipation)� Exploration
� ~ Completed� Discovery!
� Characterization� Photon+Jet� Heavy Flavor
Energy Scans
GSI-FAIR
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