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

                       

Outline of My Talk

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

Flow, v2 scaling with nq

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

                       

Really, It’s A Meta-Talk

Perfect liquid,KSS bound as QM resultViscosity primer

26-Oct-07 W.A. Zajc

                       

Really, It’s A Meta-Talk

The dénouement!AdS/CFT connection/s values

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 correspondence

Weak form: “Four-dimensional N=4 supersymmetric SU(Nc) gauge theory is

equivalent to IIB string theory with AdS5 x S5 boundary conditions.”( The Large N limit of superconformal field theories and 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 quantum 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

4

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 = “Area”/16G

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 potential”.

See “Viscosity in strongly interacting quantum field theories from black hole physics”, P. Kovtun, D.T. Son, A.O. Starinets, Phys.Rev.Lett.94:111601, 2005, hep-th/0405231

Infinite “Area” !

4

1)(ks

h

A

A

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 4-d Our 4-d worlworl

dd

String String theorist’theorist’s 5+5-d s 5+5-d worldworld

The stuff The stuff formerly formerly known as QGPknown as QGP

Heavy Heavy quark quark

moving moving through through

the the mediummedium

Energy loss Energy loss from from string string dragdrag

Jet Jet modificationmodifications from wake s from wake

fieldfield

26-Oct-07 W.A. Zajc

                       

Measuring /s Damping (flow, fluctuations, heavy quark motion)

~ /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)

4

1)2.12.01.1(

s

4

1)8.30.1(

s

4

1)0.23.1(

s

4

1)5.29.1(

s

CHARM!

26-Oct-07 W.A. Zajc

                       

Has the QCD Critical Point Been Signaled by Observations at RHIC?, R. Lacey et al., Phys.Rev.Lett.98:092301,2007 (nucl-ex/0609025) Signature: FLOW Calculation:

Payoff Plot:

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/ 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:

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 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 Hydrodynamic Limit, and the Viscosity of Hot QCD, H.-J. Drescher et al., (arXiv:0704.3553) Signature: FLOW Calculation:

Payoff Plot:

4

1)5.29.1(

4,/264.1,31/,7.0

/1

1

)(111

0

0

22

s

nsTcK

KK

vv

cdy

dN

Ac

dy

dN

AR

R

K

S

perfect

SS

Knudsen number K

Fits to PHOBOS v2 data to determine 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 Collisions 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:

4

1)0.23.1(

3for6~)/(/

2)64(~

s

NPD

TD

fHQ

HQ

Rapp and van Hees Phys.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 /s ?

Can these existing estimates be improved ? (In particular, can systematic errors be understood?)

All of these methods rely on +P = Ts . How does this change in the presence of a conserved

charge ?

In ordinary fluids, /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 /s < 1/4 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/√ not seen in J/ 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” v2(pT) for different mass particles

shows good agreement with ideal (“perfect fluid”) hydrodynamics

Roughly: ∂T =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” v2(pT) for different mass

particles shows good agreement with ideal (“perfect fluid”) hydrodynamics

Scaling flow parameters by quark content nq 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 , ~ 200 MeV .

Is any form of quasiparticle consistent with KSS bound?

All(?) AdS/CFT calculations find drag ~ √ = √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 s = 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 > 1 / T. Universal Bound on Dynamical Relaxation Times and

Black-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

                       

What Follows is the Un-Meta-Talk…

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/against

Quark Gluon Plasma (QGP) Polarized p+p collisions

Two small detectors, two large detectors Complementary capabilities Small detectors envisioned to have 3-5 year

lifetime 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

                       

RHIC and Its Experiments

STARSTAR

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

                       

Approach Will 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 B 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 State Does 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 , B ~ 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 State How 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 asymmetry persists in the final state dn/d ~ 1 + 2 v2(pT) cos (2) + ...

2v2

26-Oct-07 W.A. Zajc

                       

The “Flow” Is Perfect The “fine structure” v2(pT) for different mass particles

shows good agreement with ideal (“perfect fluid”) hydrodynamics

Roughly: ∂T =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” v2(pT) for different mass

particles shows good agreement with ideal (“perfect fluid”) hydrodynamics

Scaling flow parameters by quark content nq resolves meson-baryon separation of final state hadrons

baryonsbaryons

mesonsmesons

26-Oct-07 W.A. Zajc

                       

Probes of Dense Matter Q. How dense is the matter?

A. Do pQCD Rutherford scattering on deep interior using“auto-generated” probes:

2. Probes of dense matter

26-Oct-07 W.A. Zajc

                       

Baseline p+p Measurements with pQCD Consider measurement of 0’s in

p+p collisions at RHIC. Compare to pQCD calculation

Phys. Rev. Lett. 91, 241803 (2003)

),(

)(

),(),(

2

22

/

//

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?

Su

pp

ressed

Su

pp

ressed

En

han

ced

En

han

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 absorbed in the dense medium

GONE

=0

=

=

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 Regimes Scattered 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 expected in a dense fluid which 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 pT partner

But at low pT, 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!

26-Oct-07 W.A. Zajc

                       

How Perfect is “Perfect” ? All “realistic” hydrodynamic calculations for RHIC

fluids to date have assumed zero viscosity = 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 wrt this limit?

RHIC “fluid” mightbe at ~1 on this scale (!)

T=10T=101212 KK

(( 44

sDensityEntropy

4

)(4

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

then defined as

Dimensional estimate:

small viscosity Large cross sections Large cross sections strong couplings Strong couplings perturbation theory difficult

!

Viscosity Primer

y

v

A

F xx

σσ

1

)()(ηp

npnmfppn

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 correspondence

Weak form: “Four-dimensional N=4 supersymmetric SU(Nc) gauge theory is

equivalent to IIB string theory with AdS5 x S5 boundary conditions.”( The Large N limit of superconformal field theories and 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 quantum 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

4

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 = “Area”/16G

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 potential”.

See “Viscosity in strongly interacting quantum field theories from black hole physics”, P. Kovtun, D.T. Son, A.O. Starinets, Phys.Rev.Lett.94:111601, 2005, hep-th/0405231

Infinite “Area” !

4

1)(ks

h

A

A

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 4-d Our 4-d worlworl

dd

String String theorist’theorist’s 5+5-d s 5+5-d worldworld

The stuff The stuff formerly formerly known as QGPknown as QGP

Heavy Heavy quark quark

moving moving through through

the the mediummedium

Energy loss Energy loss from from string string dragdrag

Jet Jet modificationmodifications from wake s from wake

fieldfield

26-Oct-07 W.A. Zajc

                       

Measuring /s Damping (flow, fluctuations, heavy quark motion)

~ /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)

4

1)2.12.01.1(

s

4

1)8.30.1(

s

4

1)0.23.1(

s

4

1)5.29.1(

s

CHARM!

26-Oct-07 W.A. Zajc

                       

Has the QCD Critical Point Been Signaled by Observations at RHIC?, R. Lacey et al., Phys.Rev.Lett.98:092301,2007 (nucl-ex/0609025) Signature: FLOW Calculation:

Payoff Plot:

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/ 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:

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 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 Hydrodynamic Limit, and the Viscosity of Hot QCD, H.-J. Drescher et al., (arXiv:0704.3553) Signature: FLOW Calculation:

Payoff Plot:

4

1)5.29.1(

4,/264.1,31/,7.0

/1

1

)(111

0

0

22

s

nsTcK

KK

vv

cdy

dN

Ac

dy

dN

AR

R

K

S

perfect

SS

Knudsen number K

Fits to PHOBOS v2 data to determine 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 Collisions 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:

4

1)0.23.1(

3for6~)/(/

2)64(~

s

NPD

TD

fHQ

HQ

Rapp and van Hees Phys.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

out the interesting region from

High Tinit

~ 300 MeV

to

Low Tfinal ~ 100 MeV

30

)( 2

4

T

T

Recall per massless degree of freedom

?

26-Oct-07 W.A. Zajc

                       

LHC How could we not choose to investigate “QGP” at

every 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

                       

World Context

: 2009

: 2000RHIC II

: 2012

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 (of upgrade potential)

Source Detectors Luminosity

LHC

Preparation

(Anticipation) Exploration

~ Completed Discovery!

Characterization Photon+Jet Heavy Flavor Energy Scans

Exploitation (of upgrade potential)

Source Detectors Luminosity

GSI-FAIR