Understanding Understanding deconfinementdeconfinement: : new spectroscopy at T>Tc new spectroscopy at T>Tc

Edward ShuryakEdward ShuryakDepartment of Physics and AstronomyDepartment of Physics and Astronomy

State University of New YorkState University of New York

Stony Brook NY 11794 USAStony Brook NY 11794 USA

Outline

• The ``little bang” at RHIC

• => A strongly coupled QGP

• Lattice puzzles

• Hadrons above Tc

• Bound colored states

• AdS/CFT at finite T

RHICRHIC: a view : a view fromfrom space space

A dedicated collider for

(i) Heavy ion collisions, AuAu 100+100 GeV/N

(ii) Polarized pp, 250+250 GeV

One of the first RHIC events at STAR detector,

The average multiplicity at AuAu 200 GeV/N

Is about 5000

Spectra of various Spectra of various secondariessecondariesfrom all 4 detectorsfrom all 4 detectors

Main findings at RHIC

• Particles are produced from matter which seems to be well equilibrated (by the time it is back in hadronic phase), N1/N2 =exp(-(M_1-M_2)/T)

• Very robust collective flows were found, indicating very

strongly coupled Quark-Gluon Plasma (sQGP)

• Strong quenching of large pt jets: they do not fly away freely but are mostly (up to 90%)

absorbed by the matter. The deposited energy seemto go into another hydrodynamical motion (conical flow)

TμTμ

Tμ/2

/)(

/)(

ee

e

p

pE

E

ReminderReminderStatistical Model Statistical Model

Works well with just two parametersWorks well with just two parameters

ReminderReminderStatistical Model Statistical Model

Works well with just two parametersWorks well with just two parameters

Hadro-chemistry seems to be all done at the critical lineHadro-chemistry seems to be all done at the critical line

Hydrodynamics is simple Hydrodynamics is simple and very predictive <= only and very predictive <= only the EoS is needed,the EoS is needed,provided by the lattice (at provided by the lattice (at finite T) finite T)

Dynamic Phenomena •Expansion, Flow•Space-time evolution of thermodynamic variables

Caveat: Why and when the equilibration takes place is a tough question to answer

Local Energy-momentum

conservation:Conserved number:

Elliptic flow at RHICElliptic flow at RHICExplosion goes in all directionsExplosion goes in all directions

Radial and especiallyRadial and especiallyElliptic flowElliptic flow

The red almond-The red almond-shaped region is shaped region is where the dense where the dense matter is. Yellow matter is. Yellow

region shows region shows “spectators” which “spectators” which

fly by without fly by without interactioninteraction

The so called “jet tomography” of the initial shape of the matter

hydro describes both radial and elliptic hydro describes both radial and elliptic

flowsflows (from Phenix) v_2=<cos(2 phi)>(from Phenix) v_2=<cos(2 phi)>proton pion

Hydro models:Teaney(w/ & w/oRQMD)

Hirano(3d)

Kolb

Huovinen(w/& w/oQGP)

nucl-ex/0410003

Sonic boom from Sonic boom from quenched jets quenched jets Casalderrey,ES,Teaney, hep-ph/0410067; Casalderrey,ES,Teaney, hep-ph/0410067; H.Stocker…H.Stocker… the energy deposited the energy deposited

by jets into liquid-like by jets into liquid-like strongly coupled QGP strongly coupled QGP must go into must go into conical conical shock wavesshock waves, similar , similar to the well known to the well known sonic boom from sonic boom from supersonic planes.supersonic planes.

We solved relativistic We solved relativistic hydrodynamics and hydrodynamics and got the flow picture got the flow picture

If there are start and If there are start and end points, there are end points, there are two spheres and a two spheres and a cone tangent to bothcone tangent to both

Distribution of radial Distribution of radial velocity v_r (left) and velocity v_r (left) and modulus v (right).modulus v (right).(note tsunami-like features, a (note tsunami-like features, a positive and negative parts of the positive and negative parts of the wave)wave)

PHENIX jet pair distribution

Note: it is only projection of a cone on phi

Note 2: more

recent data from

STAR find also a minimum in

<p_t(\phi)> at

180 degr., with

a value

Consistent with background

Collective flows =>collisional regime

=> hydrodynamicsThe main assumption:

l << L(the micro scale) << (the macro scale)

(the mean free path) << (system size)

(relaxation time) << (evolution duration)

I

•In the zeroth order in l/L it is ideal hydro with a local stress tensor.

•Viscosity appears as a first order correction l/L, it is inversely proportional to the cross section and thus is (the oldest) strong coupling expansion tool

Viscosity of QGPViscosity of QGPQGP at RHIC seem to be the most idealfluid known, itsviscosity/(entropy density) =.1 -.2 water would not flow if only a drop with 1000 molecules be made

1st order correction to dist. fn.:

:Sound attenuation length

Velocity gradients

D.Teaney(’03)

What is needed to reproduce themagnitude of v2?

Huge cross sections!!

Charm transport (the diffusion coeff.)Moore&Teaney, hep-ph/0412346

Mc/T=6-7 more collision needed for equilibration

How to get 20 times pQCD ?

(Zahed and ES,2003)

• Quark-antiquark bound states don’t all melt at Tc (charmonium from lattice known prior to that…)

• Many more colored channels• all q,g have strong rescattering qqbar meson

Resonance enhancements Huge cross section due to resonance enhancement

causes elliptic flow of trapped Li atoms

Resonance enhancement near zero binding

lines provides large cross section (ES+Zahed,03)

Well, it was shown to work for strongly coupled atoms

Scattering amplitudesfor quasiparticles

M. Mannarelli. and R. Rapp hep-ph/05050080

Elliptic flow with ultracold trapped Li6 atoms, a=> infinity regime

The system is extremely dilute, but can be put into a hydro regime, with an elliptic flow, if it is specially tuned into a strong coupling regime via the so called Feshbach resonance

Similar mechanism was proposed (Zahed and myself) for QGP, in which a pair of quasiparticles is in resonance with their bound state at the “zero binding lines”

The coolest thing on Earth, T=10 nK or 10^(-12) eV can actually produce a

Micro-Bang ! (O’Hara et al, Duke )

The new spectroscopy The new spectroscopy at T>Tcat T>Tc

The QCD Phase DiagramThe QCD Phase Diagram

T

The lines marked RHIC and SPS show the paths matter makes while cooling, in Brookhaven (USA) and CERN (Switzerland)

Chemical potential mu

Theory prediction (numerical calculation, lattice QCD, Karsch et al) the pressure as a function of T (normalized to that for free quarks and gluons)

Is it weakly coupled?

lattice puzzles

• it was recently found fom correlators (Asakawa-Hatsuda,Bielefeld) that

J/,c dissolves in QGP only at T>(2-3)T_c.Why?

• How can pressure be high at T=(1.5-2)T_c

while q,g quasiparticles are quite heavy?

Because the coupling is very strong!

Because there also numerous bound states

``free energies” for static quarks (Karsch et al)

•Upper figure is normalized at small distances: one can see that there is large ``effective mass” for a static quark at T=Tc.

•Both are not yet the potentials!

•The lower figure shows the effective coupling constant

Fitting F to screened Coulomb

• Fit from Bielefld group hep-lat/0406036

•Note that the Debye radius corresponds to

``normal” (enhanced by factor 2) coupling, while the overall strength of the potential is much larger •It becomes still larger if V is usedinstead of F, see later

The potentials should have the entropy term subtracted,

which makes potentials deeper still

this is how potential I got look like for T = 1; 1.2; 1.4; 2; 4; 6; 10Tc,from right to left, from ES,Zahed hep-ph/0403127

Here is the binding and |psi(0)|^2(J/psi puzzle resolved!)

E/2MVs T/Tc

If a Coulomb coupling is too strong,falling onto the center may occur:but it is impossible to get a binding

comparable to the massBut we need massless pion/sigma at T=>Tc !

• Brown,Lee,Rho,ES hep-ph/0312175 : near-local interaction induced by the ``instanton molecules”

(also called ``hard glue” or ``epoxy”, as they survive

at T>Tc

• Their contribution is » |(0)|2 which is calculated from strong Coulomb problem

Solving for binary bound statesES+I.Zahed, hep-ph/0403127

• In QGP there is no confinement =>

• Hundreds of colored channels must have bound states as well!

The pressure puzzle is resolved!Masses, potentials and EoS from lattice are

mutually consistentM/Tc vc T/Tc and p/pSB vs T/Tc

Can we verify existence of bound states at T>Tc experimentally?

Dileptons from sQGP:

Asakawa-Asakawa-

HatsudaHatsuda, , T=1.4TT=1.4Tcc

Karsch-Laerman, T=1.5 and 3 Tc

The widths are being calculated…But see, one can see peakson the lattice

A gift by the string theorists, the AdS/CFT correspondence,

should help us understand sQGP

QCD vs CFT: let us start with EoS

(The famous .8 explained!)

Strongly coupled CFT plasma is a very good liquid!

• AdS/CFT calculation (D.Son et al 2003)

of the correlator <Tmunu(x) Tmunu(0)>

Via graviton propagator

=>

viscosity/ (entropy density)

=> It is about as small as observed at RHIC!

4// hbars

Bound states in AdS/CFT(ES and Zahed, PRD 2004)

• The quasiparticles are heavyM_q =O(sqrt(lambda) T) >> T, exp(-M_q/T)<<1• But there should be light binary bound states

with the mass O(M_q/sqrt(lambda))=O(T) • Using Dirac/KG eqns with supercritical coupling

one gets states falling on the center if l<sqrt(lambda)

• But recent work on ``quarkonia” with D3D7 brane construction (e.g.M.Strassler et al 05)

found that the s-wave states survive, with exactly the right mass O(M_q/sqrt(lambda))

A complete ``gravity dual” for RHIC A complete ``gravity dual” for RHIC from 10-d GR? from 10-d GR? (ES,Sin,Zahed, in progress)(ES,Sin,Zahed, in progress)

Black Holes + Howking rad. Is used Black Holes + Howking rad. Is used to mimic the finite Tto mimic the finite T

How How black hole is producedblack hole is produced can be can be calculated from GR (tHooft … calculated from GR (tHooft … Nastase)Nastase)

Entropy production => black hole Entropy production => black hole formation,formation, falling into it is viscosity falling into it is viscosity

MovingMoving brane => hydro expansion brane => hydro expansion

Conclusions

• QGP as a “matter” in the usual sense, not a bunch of particles, has been produced at SPS/RHIC

• It shows very robust collective flows. The EoS is as expected: but QGP seems to be the most ideal fluid known

eta/hbar s=.1-.2 <<1

• All of this hints that QGP is in a strong coupling regime, with new spectroscopy of colored states

• Interesting analogies with other strongly coupled systems

• ``quantum gases”• AdS/CFT

Is such a sonic boom already Is such a sonic boom already observed?observed?Mean Cs=.33 time average over 3 stages=>Mean Cs=.33 time average over 3 stages=>

M.Miller, QM04

flow of matter normal to the Mach cone seems to be observed! See data from STAR,

+/-1.23=1.91,4.37

away <pT> dependence on angle (STAR,preliminary)

Preliminary

<pT> (phi) has a dip structure in central AA.

Mach shock wave?