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ALICE@Hanyang
Quest for new states of matter at RHIC
Sticky Quark-Gluon-Molasses
in collaboration with
G.E. Brown, M. Rho, E. Shuryak
NPA 740 (2004) 171
hep-ph/0405114; hep-ph/0408253
Chang-Hwan Lee & Hong-Jo Park @
My main works before Pusan
Astro-Hadron Physics
- Kaon Condensation in Neutron Star (Ph.D.)
[ CH Lee, Physics Reports 275 (1996) 255 ]
- Kaon production in Heavy Ion Collisions [KaoS]
[ Li, Lee, Brown, PRL 79 (1997) 5214 ]
- Evolution of Neutron Stars and Black Holes
March 2003
Heavy Ion Physics in Pusan since 2003
Theory :
CH Lee
Hong-Jo Park (Ph.D. student)
Eun-Seok Park (Master student)
Experiment : IK Yoo et al.
Scaling Mesons from NS to RHIC
Early Universe
Quark-Gluon-Molasses
RHIC
T
Hadrons
K bound system
Density
Neutron Star
Scaling Meson : previous works by Korean collaborations
 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.
New Recent Developments
Kaon Condensation:
previous works
reduce pressure
forming denser medium
MNS,max = 1.5 Msun
p + e-
M
p + K-
e- chemical potential
Kaon effective mass
density
“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
Method
Isovector
Deformation
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
Very strong K--p attraction
 deep discrete bound states: with binding
energy ~ 100 MeV
 Strong in-medium KN interactions.
 Precursor to kaon condensation.
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
Brown/Rho scaling
M
Rho/Harada/Sasaki
Vector Manifestation
RG fixed point
A1
r
s
?
Vanishing coupling !
RHIC
p
LHC
Tc
Q: What happens at RHIC/LHC whey they cross Tc ?
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
Our point of view
Equilibrium of hadronic mode has to be
already established above Tc at RHIC !
[ Below Tc, coupling vanishes ! ]
Questions
 RHIC:
Can hadronic modes survive after phase
transition ?
Our Principle
We may be biased, but
Prejudice saves time for thinking !
Unorthodox phase structure (working hypothesis)
M
2mq*
A1
r
Mesons
disappear
qq
s
Sticky
QGM
p
Tc
QGP
Tzb
 pion, sigma masses go to zero at T = Tc;+:
smooth phase transition (2nd order)
at RHIC, it is believed that T>Tc has been reached.
Q) Have we really seen QGP at RHIC ?
Our Answer is “No” !
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
Motivation
RHIC: beyond phase transition
 RHIC data is consistent with ideal
hydrodynamics.
 It is the most perfect liquid known:
viscosity/entropy (h/s) = 0.1 (much less
than that of most liquids, e.g. h/s=1 for
He4 at high pressure, 40 for water)
 Matter formed at RHIC is not weakly
interacting quasi-particle gas.
Hydro vs RHIC data [Teaney et al.]
What happened
at RHIC ?
Hydrodynamical
Expansion
Elliptic Flow
Hydrodynamical
expansion of
trapped Li6
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
Strong coupling
regime above Tc
Lattice Calculation by F. Zantow et al. (Bielefeld)
Are there hadrons above Tc ?
 Old point of view: most hadrons including J/y 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 as = 0.5 is reached.
 quark-antiquark bound states exist
for Tc < T < Tzerobinding
due
to relativistic effects +
spinspin interaction +
nonperturbative 4point NJL-type interactions.
Unorthodox phase structure (Hypothesis)
M
2mq*
A1
r
Mesons
disappear
qq
s
Sticky
QGM
p
Tc
QGP
Tzb
 pion, sigma masses go to zero at T = Tc;+:
smooth phase transition (2nd order)
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)
strong
coupling
regime ?
Assumption
thermal mass from lattice
Klein-Gordon equation
Color Coulomb interaction
 solve Klein-Gordon equation
in relativistic regime
4 -point Interaction (NJL type: Instantons ?)
Lattice + NJL
BGLR: Phys. Rep. 391 (2004) 353
Binding energies at Tc (slightly above)
as
DECoulomb
sqrt(<r2>)
DE4-point
0.50
-0.483
0.360
-0.994
0.55
-0.595
0.313
-1.385
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 ?
in collaboration with F. Zantow (Bielefeld Group)
Still on-going, but we are finding similar results
Potential extracted from Free energy [Bielefeld]
closed : data
open: fitting
Binding energy from 2-body potential
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 ?
…….
Working Hypothesis as Conclusions
 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.
RHIC found “sticky quark gluon molasses”
instead of QGP !
For the Future of Korea-EU ALICE Collaboration
Key words: early universe,
quarks, gluons, QGP, dense
matter, dense stellar matter,
neutron stars, … …
Simple-minded theorist’s point of view
“Alice wonderland” is one of the best place
where physicists, astrophysicsists, cosmologists,
and astronomers can work together.