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Search for Collective Phenomena

Search for Collective Phenomena

Art Poskanzer

In honor of Miklos Gyulassy’s60th birthday

1995

Not a surprise party

History of the

Emphasizing Miklos’ Contributions

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Same Topic 26 Years AgoSame Topic 26 Years Ago

Nuclear Physics AVolume 400, 23 May 1983, Pages 31-41

Copyright © 1983 Published by Elsevier B.V.

Nuclear collisions from AMeV to ATeV:From nuclear to quark matter

Miklos Gyulassy

Nuclear Science Division, Lawrence Berkeley Laboratory University of California,Berkeley, CA 94720 USA

Opening talk at Nucleus-Nucleus ‘82 at MSU:

Gyulassy 1983

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Collisions of Swiss WatchesCollisions of Swiss Watches

Poskanzer, CERN colloquium (1980)

general negative attitude

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Flowers Amongst the WeedsFlowers Amongst the WeedsAt the 2nd Heavy Ion Summer Study in 1974 Wladek Swiateckitalked about “Clearing the weeds and Getting to the heart of the matter”

In the 35 years since there have been a few flowers

Swiatecki 1983

to find a flower

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QM87 NordkirchenQM87 NordkirchenConcluding Remarks by Miklos Gyulassy

22 years ago, it was the most memorable talk I have ever heard

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Shock Waves - 1959Shock Waves - 1959

Annals of Physics 6, 1 (1959)

First prediction of collective flow at high energy

Angle depends on the speed of soundwhich depends on the Eq. of State

50 years ago

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Shock WavesShock Waves

W. Scheid, H. Muller, and W. Greiner,PRL 32, 741 (1974)

M.I. Sobel, P.J. Siemens, J.P. Bondorf, andH.A. Bethe, Nucl. Phys. A251, 502 (1975)

G.F. Chapline, M.H. Johnson, E. Teller, and M.S. Weiss, PRD 8, 4302 (1973)

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No Shock WavesNo Shock Waves

H.G. Baumgardt et al., Z. Physik A 273, 359 (1973)Peaks in tracks in AgCl crystals

Poskanzer and Greiner 1984

d/d

reviewed in H.R. Schmidt, Int. J. Mod. Phys. A6, 3865 (1991)GSI-LBL, A.M. Poskanzer et al., PRL 35, 1701 (1975)

d/dΩ

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Shock Waves AgainShock Waves Again

D.H. Rischke, H. Stoecker, and W. Greiner. PRD 42, 2283 (1990)

Flow in conical shock wavesAway side jet

J. Casalderrey-Solana, E.V. Shuryak,and D. Tracy, arXiv hep-ph/0411315 (2004)

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STARSTAR

Phys. Rev. Lett. 102, 052302 (2009)

structures are evidence of conical emission of hadrons correlated with high p⊥ particles.

C. Pruneau, QM06, S671

3-particle correlations

No clear evidence for conicalemission is observed usingcumulates.

However, see Ulery and Wang, PRC 79, 024904 (2009)

CATHIE-RIKEN Workshop:Critical Assessment of Theory and Experiment on Correlations at RHICFebruary 25-26, 2009

I think experiments not conclusive

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Should Not BeShould Not Be

Bouras, Molnar, Niemi, Xu, El, Fouchler, Greiner, Rischke, ArXiv:0902.1927

an /s ratio larger than 0.2 prevents the developmentof well-defined shock waves on timescales typical forultrarelativistic heavy-ion collisions.

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Mach ConesMach ConesMiklos’ last 10 papers have been on Mach Cones

QuickTime™ and a decompressor

are needed to see this picture.

G. Torrieri, B. Betz, J. Noronha, and M. Gyulassy, arXiv:0901.0230

Theory very complicated!

J. Noronha, M. Gyulassy, and G. Torrieri, PRL 102, 102301 (2009)

Doubts PHENIX results are dueto ordinary Mach cones

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FireballFireball

G.D. Westfall et al., Phys. Rev. Letters 37, 1202 (1976)

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Homework ProblemHomework Problem Assigned by Miklos at the 3rd Summer Study in 1976

Calculate p spectrum of 250 MeV/A Ne + U

Nine solutions submitted Factors of 2 - 5 away from the data

“The most successful model in reproducing the gross features of the data is the fireball model”

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Many ProbesMany Probes

abt. 1986

Collective Flow

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SphericitySphericity

Best ellipsoid for each event by diagonalizingkinetic energy flow tensor:

pz

(Beam)

Reaction plane

x

y

z

s

py

px

P. Danielewicz and M. Gyulassy Phys. Lett. B 129, 283 (1983)M. Gyulassy, K.A. Frankel, and H. Stocker, Phys. Lett. 110B, 185 (1982)

Major axis and beam axisdetermine event plane

M. Lisa (1999)

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Polar Flow AnglePolar Flow Angle

Gyulassy:“The only true signature of collective flowis a clear maximum of dN/d cos away from = 0”

Directed Flow

M. Gyulassy, K.A. Frankel, and H. Stocker, Phys. Lett. 110B, 185 (1982)P. Danielewicz and M. Gyulassy, Phys. Lett. 129B, 283 (1983)

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Discovery of Collective FlowDiscovery of Collective Flow

Plastic Ball, Gustafsson et al., PRL 52, 1590 (1984)

Non-zero flow angle distributionfor Nb, but not CadN/dcos

Bevalac 400 MeV/A

Directed Flow

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Squeeze-outSqueeze-outbounce

squeeze squeeze

400 MeV/A Au+Au (MUL 3)

Plastic Ball, H.H. Gutbrod et al., Phys. Lett. B216, 267 (1989)Diogene, M. Demoulins et al., Phys. Lett. B241, 476 (1990)Plastic Ball, H.H. Gutbrod et al., PRC 42, 640 (1991)

Negative Elliptic Flow

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Expansion In PlaneExpansion In Plane

Hiroshi Masui (2008)

spatialanisotropy

momentumanisotropy

2

v2

Positive Elliptic Flow

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Discovery of Elliptic Flow at RHIC

Discovery of Elliptic Flow at RHIC

STAR, K.H. Ackermann et al., PRL 86, 402 (2001)

First paper from STAR

Dramatic effect:

Significant that data approach hydrofor central collisionsWas not true at lower beam energies

hydro predictions

peripheral centralpeak / valley = (1 + 2 v2) / (1 - 2 v2) = 1.8

22A. Wetzler (2005)

Elliptic Flow vs. Beam EnergyElliptic Flow vs. Beam Energy

25% most centralmid-rapidity

all v2EP

six decades

In-planeelliptic flow

squeeze-out

bounce-offspinning

powerful, widely-used tool,to study EOS ofnuclear matter

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Transverse Plane

Elliptic FlowElliptic Flow

Rescattering Converts space to

momentum anisotropy Becomes more spherical

Self-quenching Early time

thermalization

v2

t (fm/c)

Zhang, Gyulassy, Ko, Phys. Lett. B455 (1999) 45

Main contribution to elliptic flow early in the

collision

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quarks

mesons

baryons

plotted vs.trans. kinetic energy

PHENIX, PRL 98, 162301 (2007)

Scaling with Number of QuarksScaling with Number of Quarks

both axes scaled by numberof constituent quarks

nq = 2 for mesonsnq = 3 for baryons

recombination of quarksquarks have v2 before hadronization

STAR, PRL 95, 122301 (2005)

S. Voloshin, QM02, 379c (2003)

particle massdependence

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Eq.

QuickTime™ and a decompressor

are needed to see this picture.

event plane resolution

root-mean-square

mean

FluctuationsFluctuations

Data: PHOBOS+Eq.: Ollitrault, Poskanzer, and Voloshin, QM09, ArXiv

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Fluctuations and Nonflow Corr.Fluctuations and Nonflow Corr.

published corrected to Part. Plane

Ollitrault, Poskanzer, and Voloshin, QM09, arXiv

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Correction to Reaction PlaneCorrection to Reaction Plane

Ollitrault, Poskanzer, and Voloshin, QM09, arXiv

Glauber fluctuations

CGC fluctuations

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Shear ViscosityShear Viscosity

shear viscosityentropy density

Conjecture was derived from string theory but has simple interpretation based on the uncertainty principle:

Mean free path must be bigger than De Broglie wavelength. Larry McLerran

Small shear viscosity meanssmall mean free path, which meansstrongly coupled

Danielewicz and Gyulassy, PRD 31, 53 (1985)

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Viscous HydrodynamicsViscous Hydrodynamics

Romatschke2, PRL 99, 172301 (2007)

Hydro: viscosity lowers v2

Data: removing non-flow and fluctuations lowers v2

Both data and hydro need more work on these effects• But approximately at the uncertainty principle value• Thus /s is no more than 5 times bigger than the minimum value

STAR, B.I. Abelev et al., arXiv:0801.3466; PRC, submitted (2008)

= 1/(4)

estimatedremovalof non-flowand fluctuations

STAR data

non-viscous

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FutureFuture More precise multi-particle v2

Reaction Plane values For many identified species

Quark content Do charm and bottom quarks flow?

Equilibration Explain RAA and v2 at the same time

Universal understanding

31in Hungrey, 2001

Miklos found the flowers amongst the weeds: