Sticky Quark-Gluon-Molasses

ALICE@Hanyang

in collaboration with

G.E. Brown, M. Rho, E. Shuryak

NPA 740 (2004) 171

hep-ph/0405114; hep-ph/0408253

Quest for new states of matter at RHIC

Chang-Hwan Lee & Hong-Jo Park @

My main works before Pusan

- Kaon Condensation in Neutron Star (Ph.D.)

Astro-Hadron Physics

- Evolution of Neutron Stars and Black Holes

[ CH Lee, Physics Reports 275 (1996) 255 ]

- Kaon production in Heavy Ion Collisions [KaoS]

[ Li, Lee, Brown, PRL 79 (1997) 5214 ]

March 2003

Heavy Ion Physics in Pusan since 2003Theory : CH Lee

Hong-Jo Park (Ph.D. student)

Eun-Seok Park (Master student)

Experiment : IK Yoo et al.

T

Density

Hadrons

Neutron Star

Early Universe

RHIC

K bound system

Scaling Mesons from NS to RHIC

Quark-Gluon-Molasses

Brown/Rho Scaling

Vector Manifestation [Harada/Yamawaki/Rho..]

Dilepton Experiment: rho-meson mass drops.

Kaon production in heavy ion collisions [KaoS]

Kaon condensation: kaons are condensed in neutron stars due to dropping kaon mass.

Scaling Meson : previous works by Korean collaborations

New Recent Developments

p + e- p + K-

Kaon Condensation: previous works

Kaon effective mass

e- chemical potential

density

M

reduce pressure forming denser medium MNS,max = 1.5 Msun

“Maximum mass of NS = 1.5 solar mass” is still consistent with all the binary radio

pulsars.

new developments: Kaonic Nuclear Bound States

Is kaon-nuclear attraction is strong enough to make kaon condensation ?

Yamazaki et al. (2003)

3He 3HeK-

Antisymmetric Molecular Dynamics MethodIsovectorDeformation Dote et al. 2002

PLB 597 (2004) 263

Total binding energy : 194 MeV from K-ppn

Mass = 3117 MeV, width < 21 MeV

Kaonic Nuclei - Mini Strange Star

deep discrete bound states: with binding energy ~ 100 MeV

Strong in-medium KN interactions. Precursor to kaon condensation.

Very strong K--p attraction

Scaling Mesons in Neutron Stars

After Recent New Observations

Isolated Single Neutron Stars

Binary Neutron Stars

Kaon Condensation still open possibility !

Scaling Mesons below Tc

Vector Manifestation [Harada/Yamawaki/Rho …]

- When chiral symmetry is restored (at Tc)

- Renormalization Group Fixed Points give us

Vanishing pi, rho mass

Vanishing coupling

Tc

A1M

?

Brown/Rho scaling

Q: What happens at RHIC/LHC whey they cross Tc ?

Vector Manifestation RG

fixed point

Vanishing coupling !

Rho/Harada/Sasaki

RHICLHC

Braun-Munzinger, Stachel, Wetterich (2003)

Chemical freezeout temperature is close to Tc.

Equilibration in the chirally broken sector just below Tc.

“rho/pi” ratio was lower than STAR experiment roughly by a factor of 2

Equilibrium of hadronic mode has to be already established above Tc at RHIC !

[ Below Tc, coupling vanishes ! ]

Our point of view

Questions

RHIC: Can hadronic modes survive after phase transition ?

Prejudice saves time for thinking !

Our Principle

We may be biased, but

Unorthodox phase structure (working hypothesis)

pion, sigma masses go to zero at T = Tc;+: smooth phase transition (2nd order)

QGPSticky

QGM

Mesons disappe

ar

Tc Tzb

A1M2mq*

qq

What is (perturbative) QGP above Tc ?

weakly interacting regime: weak running coupling.

quarks are not locked into hadrons.

quarks, antiquarks & gluons are proper thermodynamic variables

Q) Have we really seen QGP at RHIC ?

Our Answer is “No” !

at RHIC, it is believed that T>Tc has been reached.

RHIC data is consistent with ideal hydrodynamics.

It is the most perfect liquid known: viscosity/entropy (/s) = 0.1 (much less than that of most liquids, e.g. /s=1 for He4 at high pressure, 40 for water)

Matter formed at RHIC is not weakly interacting quasi-particle gas.

Motivation

RHIC: beyond phase transition

Hydro vs RHIC data [Teaney et al.]

Hydrodynamical expansion of tra

pped Li6

What happened at RHIC ?

Hydrodynamical Expansion

Elliptic Flow

Question

Why does the matter formed at RHIC behaves as a nearly ideal fluid ?

What is the matter formed at RHIC ?

Because it’s in a very strong coupling regime

We named it “Sticky Quark Gluon Molasses” It is not a plasma !

Running coupling at large diatance

Lattice Calculation by F. Zantow et al. (Bielefeld)

Strong coupling regime above Tc

Are there hadrons above Tc ?

Old point of view: most hadrons including J/ melt there.

Brown, Lee, Rho, Shuryak [NPA 740 (2004) 171]: quark-antiquark bound states exists above Tc including low-mass pionic modes.

New Idea

at T>Tc the color charge continues to run to larger values, stopped by the Debye screening only when s = 0.5 is reached.

quark-antiquark bound states exist for Tc < T < Tzerobinding due to relativistic effects + spin-spin interaction + nonperturbative 4-point NJL-type interactions.

Unorthodox phase structure (Hypothesis)

pion, sigma masses go to zero at T = Tc;+: smooth phase transition (2nd order)

QGPSticky

QGM

Mesons disappe

ar

Tc Tzb

A1M2mq*

qq

2nd order phase transition

Q: Can we make low-mass bound states above Tc ?We have only partial answers, but working on the problem

Our toy model (combined with lattice results)

thermal mass from lattice

Klein-Gordon equation

Assumption

strong coupling regime ?

Color Coulomb interaction

solve Klein-Gordon equation in relativistic regime

4 -point Interaction (NJL type: Instantons ?)

BGLR: Phys. Rep. 391 (2004) 353

Lattice + NJL

s ECoulomb sqrt(<r2>) E4-point

0.50 -0.483 0.360 -0.994

0.55 -0.595 0.313 -1.385

Binding energies at Tc (slightly above)

in GeV, fm unit

* Mq = 1 GeV (extrapolation from LGS) is used.

Binding energy from Color Coulomb & 4-point interaction

is enough to make massless bound states

What the lattice free energy tell us ?

Still on-going, but we are finding similar results

in collaboration with F. Zantow (Bielefeld Group)

Potential extracted from Free energy [Bielefeld]

closed : data open: fitting

Binding energy from 2-body potential

Thermal mass

dependence

Bound state disappear

Mass of bound states with 2-body interaction

Not enough binding yet !

What has to be done in the (near) future ?

Better understanding of thermal masses above Tc ?

4-point interactions ?

Dileptons from RHIC ?

Baryons ?

High pt particles ?

…….

Matter formed at RHIC is not perturbative QGP (weak coupling), but is in a strong coupling regime.

All s-wave mesons do not melt at Tc, but at higher temperature, i.e., zero binding lines.

Hadronic masses (for sigma, pi, rho, A1) goes to zero both below and above Tc.

Working Hypothesis as Conclusions

RHIC found “sticky quark gluon molasses” instead of QGP !

For the Future of Korea-EU ALICE Collaboration

“Alice wonderland” is one of the best place where physicists, astrophysicsists, cosmologists, and astronomers can work together.

Simple-minded theorist’s point of view

Key words: early universe, quarks, gluons, QGP, dense matter, dense stellar matter, neutron stars, … …