Behind QGP Investigating the matter of the early Universe Investigating the matter of the early...

Behind QGPBehind QGP

• Investigating the matter of the early Investigating the matter of the early UniverseUniverse

• Is the form of this matter Quark Gluon Is the form of this matter Quark Gluon Plasma?Plasma?

• What energy density, temperature?What energy density, temperature?• Evidence for a Evidence for a Quark FluidQuark Fluid instead of instead of

a QGPa QGP• Further properties of the matterFurther properties of the matter

Exploring the properties of the QCD Matter Exploring the properties of the QCD Matter

Máté Csanád, Eötvös University BudapestMáté Csanád, Eötvös University BudapestISSP’06, August 29 – September 7, EriceISSP’06, August 29 – September 7, Erice

22M. Csanád, ISSP’06 EriceM. Csanád, ISSP’06 Erice

Discovering new laws of Discovering new laws of NatureNature

"In general we look for a new law by the following process. "In general we look for a new law by the following process. First we guess it. First we guess it. Then we compare the consequences of the guess to see whatThen we compare the consequences of the guess to see whatwould be implied if this law that we guessed is right. would be implied if this law that we guessed is right. Then we compare the result of the computation to nature, withThen we compare the result of the computation to nature, withexperiment or experience, compare it directly with observation,experiment or experience, compare it directly with observation,to see if it works. to see if it works. If it disagrees with experiment it is wrong.If it disagrees with experiment it is wrong.

In that simple statement is the key to science. In that simple statement is the key to science. It does not make any difference how beautiful your guess is. It does not make any difference how beautiful your guess is. It does not make any difference how smart you are, who made It does not make any difference how smart you are, who made thetheguess, or what his name is — if it disagrees with experiment it guess, or what his name is — if it disagrees with experiment it isiswrong.”wrong.”

/R.P. Feynman//R.P. Feynman/


How did the Universe look How did the Universe look like?like?• Expectation: Quark Gluon PlasmaExpectation: Quark Gluon Plasma

• Form of matter?Form of matter?• Plasma? Gas? Fluid?Plasma? Gas? Fluid?

• Degrees of freedom?Degrees of freedom?• Quarks and gluons?Quarks and gluons?

• Energy, temperature?Energy, temperature?• Lattice QCD:Lattice QCD:

deconfined above ~ 170MeV deconfined above ~ 170MeV 2 terakelvin 2 terakelvin

• We will see: rather We will see: rather Quark FluidQuark Fluid than QGP than QGP• Metaphor or frozen worldMetaphor or frozen world

• Theoretically predicted other forms of iceTheoretically predicted other forms of ice• Experiment: smash ice to ice, detect re-frozen ice-Experiment: smash ice to ice, detect re-frozen ice-

particlesparticles

• A lot predictions or guesses based on QGP A lot predictions or guesses based on QGP failedfailed

44M. Csanád, ISSP’06 EriceM. Csanád, ISSP’06 EriceM. Csanád, T. Csörgő, A. Ster et al. nucl-th/0512078M. Csanád, T. Csörgő, A. Ster et al. nucl-th/0512078

Elliptic flow: vElliptic flow: v22

tn t

nt

2t

2t0

dn(p , ,y)=1+2 v (p )cos(n )

dp d dy

dn(p , ,y)v cos(2 )

dp d dy

tn t

nt

2t

2t0

dn(p , ,y)=1+2 v (p )cos(n )

dp d dy

dn(p , ,y)v cos(2 )

dp d dy

• Second Fourier coefficient ofSecond Fourier coefficient ofpptt-spectra in transverse plane -spectra in transverse plane angleangle

• Gas, no interaction: spherical Gas, no interaction: spherical symmetry, vsymmetry, v22 = 0 = 0

• Hydrodynamic, collective behavior: Hydrodynamic, collective behavior: vv22 > 0 > 0

• FluidFluid dynamics describes v dynamics describes v22


Relativistic Perfect FluidsRelativistic Perfect Fluids• Success of Success of hydrohydro models models

• Elliptic flowElliptic flow• Hydro scaling of spectra slopes and correlation length’Hydro scaling of spectra slopes and correlation length’

• A new family of exact solutions:A new family of exact solutions:• T. Csörgő, M. I. Nagy, M. Csanád: nucl-th/0605070T. Csörgő, M. I. Nagy, M. Csanád: nucl-th/0605070

• Two improvement to the Bjorken solution:Two improvement to the Bjorken solution:• Finite Rapidity distribution ~ Landau’s solutionFinite Rapidity distribution ~ Landau’s solution• Relativistic acceleration Relativistic acceleration

0

0

00

v tanh

n n (s)

1T T

(s)

0

0

00

v tanh

n n (s)

1T T

(s)

Velocity fieldVelocity field

Number densityNumber density

TemperatureTemperature


AAdvanced dvanced 00 estimate estimate• Width of dn/dWidth of dn/d distribution is due to distribution is due to

acceleration, controlled by parameter acceleration, controlled by parameter • Acceleration yields longitudinal explosionAcceleration yields longitudinal explosion

• Bjorken estimate underestimates Bjorken estimate underestimates initial energy densityinitial energy density

t f0 Bj2

0 f 00

m ddn dy

d d dR

t f

0 Bj20 f 00

m ddn dy

d d dR

1

0 f

Bj 0

2 1

1

0 f

Bj 0

2 1

Here Here f f //0 0 15 usually 15 usually


AAdvanced dvanced 00 estimate estimate

• Fits to BRAHMS dn/dFits to BRAHMS dn/d data: data: 2 2

• Correction factors of Correction factors of 00//BjBj 2.0 – 2.2 2.0 – 2.2

• Inital energy density of Inital energy density of 00 ~ 10 – 30 ~ 10 – 30 GeV/fmGeV/fm33


Temperature estimateTemperature estimate• Buda-Lund Buda-Lund hydro modelhydro model compared to the data (fits) compared to the data (fits)• At freeze-out, 1/8 of the volume above At freeze-out, 1/8 of the volume above

deconfinement temperaturedeconfinement temperature• At this high temperature: not gas, but fluid!At this high temperature: not gas, but fluid!

spectra

v2

Csanád, Csörgő, Csanád, Csörgő, Ster, nucl-th/0310040Ster, nucl-th/0310040, , nucl-thnucl-th//0311102, nucl-th/04030740311102, nucl-th/0403074

spectra

v2


Universal hydro scaling of Universal hydro scaling of vv22 • Buda-Lund Buda-Lund

hydrohydro: prediction : prediction of scale function of scale function II11/I/I00 (2003,2004) (2003,2004)

• PHENIX (2005), PHENIX (2005), PHOBOS (2006) PHOBOS (2006) and STAR (2005) and STAR (2005) data do collapsedata do collapse

• Prediction based Prediction based on on perfect hydroperfect hydro is VALIDis VALID

Csörgő, Akkelin, Hama, Lukács, Sinyukov (Phys. Rev. C67, 034904, 2003)Csörgő, Akkelin, Hama, Lukács, Sinyukov (Phys. Rev. C67, 034904, 2003)Csanád, Csörgő, Lörstad, Ster (Nucl. Phys. A742:80-94,2004)Csanád, Csörgő, Lörstad, Ster (Nucl. Phys. A742:80-94,2004)

Csanád, Csörgő, Lörstad, Ster et al. nucl-th/0512078Csanád, Csörgő, Lörstad, Ster et al. nucl-th/0512078

I1/I0


Scaling and scaling Scaling and scaling violationsviolations

• Universal hydro scaling breaksUniversal hydro scaling breaks• VALENCE QUARK number scaling sets inVALENCE QUARK number scaling sets in• Fluid of QUARKS!!Fluid of QUARKS!!

PHENIX Collaboration, nucl-ex/0608033PHENIX Collaboration, nucl-ex/0608033

0 1 2 3 4 5

v 2

0.00

0.05

0.10

0.15

0.20

0.25

0.30 s 200 GeVNNAu Au

0SKp

fsTy

5 < Centrality < 30 %

K

(STAR)

(PHENIX)

(STAR)

(PHENIX)

(PHENIX)


Chiral symmetry Chiral symmetry restoration?restoration?

• Prediction: Prediction: ’ mass reduction in hot and ’ mass reduction in hot and dense matter due to Udense matter due to UAA(1) symmetry (1) symmetry restorationrestoration

• Idea: measure Idea: measure (m(mtt) dependence at low ) dependence at low momentamomenta

Kapusta, Kharzeev, McLerranKapusta, Kharzeev, McLerran

Phys.Rev.D53:5028-5033,1996Phys.Rev.D53:5028-5033,1996

Z. Huang, X-N. WangZ. Huang, X-N. Wang

Phys.Rev.D53(1996)5034Phys.Rev.D53(1996)5034

Vance, Csörgő Kharzeev Vance, Csörgő Kharzeev

Phys.Rev.Lett.81:2205-2208,1998Phys.Rev.Lett.81:2205-2208,1998

NA44, NA44, S+PbS+Pb


Why theWhy the(m(mtt) dependence) dependence

Prediction:Prediction:In hot and dense matterIn hot and dense matter

’’ mass reductionmass reduction

Enhanced Enhanced ’’ content content

Decay:Decay:

’’+++ + ++-- ((00++++++−−)+)+++++−−

Long lifetimeLong lifetime

Average pAverage ptt of of ’s 138 MeV’s 138 MeV

More non-interacting More non-interacting ’s at 138 ’s at 138

MeVMeV

(m(mtt) measures ratio of interacting ) measures ratio of interacting ’s’s

A hole in A hole in (m(mtt) )

PHENIX FINAL DATAAu+Au 200 GeV

S. S. Adler et al., PRL93,152302(2004)

(m(mtt) measures fraction of interacting ) measures fraction of interacting ’s’s


Analysis of new, low pAnalysis of new, low ptt data data• UUAA(1) restoration tested(1) restoration tested

• Results critically dependent on understanding of Results critically dependent on understanding of statistical and systematic errorsstatistical and systematic errors

• Additional analysis required for definitive statementAdditional analysis required for definitive statement

PHENIX PRELIMINARY

M. Csanád for the PHENIX Collaboration, Quark Matter 2005, BudapestM. Csanád for the PHENIX Collaboration, Quark Matter 2005, Budapestnucl-ex/0509042nucl-ex/0509042


What matter do we see?What matter do we see?• We see a perfect fluidWe see a perfect fluid

• Elliptic flow: hydro signalElliptic flow: hydro signal• Broad range success of hydro modelsBroad range success of hydro models

• It is deconfinedIt is deconfined• High enough temperatures based on lQCDHigh enough temperatures based on lQCD

• Degrees of freedom: quarksDegrees of freedom: quarks• Valence quark number scaling Valence quark number scaling

complimentary to hydro scalingcomplimentary to hydro scaling

• Signal of partial symmetry restorationSignal of partial symmetry restoration• Mass reduction of Mass reduction of ’’ (preliminary) (preliminary)

• A lot more not covered hereA lot more not covered here• Rare probes, penetrating probes, jet Rare probes, penetrating probes, jet

suppression…suppression…


Where do we go?Where do we go?

• Explore all properties of the Quark Explore all properties of the Quark MatterMatter• Analyse more dataAnalyse more data• Make further guessesMake further guesses• Use higher luminosityUse higher luminosity

• Full map of the QCD phase diagramFull map of the QCD phase diagram• Go to higher energyGo to higher energy• Compare to lower energy dataCompare to lower energy data• Use different colliding systems (e, p)Use different colliding systems (e, p)

• Columbus has just arrived to the new Columbus has just arrived to the new worldworld

Behind QGP Investigating the matter of the early Universe Investigating the matter of the early...

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