Sticky Quark-Gluon-Molasses

1. 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 @

2. 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

3. March 2003

4. 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.

5. Scaling Mesons from NS to RHIC Early Universe Quark-Gluon-Molasses RHIC T Hadrons K bound system Neutron Star Density

6. 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

7. Kaon Condensation: previous works reduce pressure forming denser medium MNS,max = 1.5 Msun p + e- p + K- M e- chemical potential Kaon effective mass density “Maximum mass of NS = 1.5 solar mass” is still consistent with all the binary radio pulsars.

8. new developments: Kaonic Nuclear Bound States • Is kaon-nuclear attraction is strong enough to make kaon condensation ? Yamazaki et al. (2003)

9. Antisymmetric Molecular Dynamics Method Isovector Deformation Dote et al. 2002 3He 3HeK-

10. PLB 597 (2004) 263 Total binding energy : 194 MeV from K-ppn Mass = 3117 MeV, width < 21 MeV

11. deep discrete bound states:with binding energy ~ 100 MeV Strong in-medium KN interactions. Precursor to kaon condensation. Kaonic Nuclei - Mini Strange Star Very strong K--p attraction

12. Scaling Mesons in Neutron Stars After Recent New Observations • Isolated Single Neutron Stars • Binary Neutron Stars Kaon Condensation still open possibility !

13. 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

14. Brown/Rho scaling Rho/Harada/Sasaki A1 Vector Manifestation RG fixed point Vanishing coupling ! M r ? s RHIC LHC p Tc Q: What happens at RHIC/LHC whey they cross Tc ?

15. 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 ! ]

16. Questions • RHIC: Can hadronic modes survive after phase transition ?

17. Our Principle We may be biased, but Prejudice saves time for thinking !

18. Unorthodox phase structure (working hypothesis) 2mq* A1 M r Mesons disappear qq s Sticky QGM QGP p Tc Tzb • pion, sigma masses go to zero at T = Tc;+: smooth phase transition (2nd order)

19. 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

20. 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.

21. Hydro vs RHIC data [Teaney et al.]

22. What happened at RHIC ? Hydrodynamical Expansion Elliptic Flow Hydrodynamical expansion of trapped Li6

23. 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 !

24. Running coupling at large diatance Strong coupling regime above Tc Lattice Calculation by F. Zantow et al. (Bielefeld)

25. 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.

26. 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 < Tzerobindingdue to relativistic effects + spin-spin interaction + nonperturbative 4-point NJL-type interactions.

27. Unorthodox phase structure (Hypothesis) 2mq* A1 M r Mesons disappear qq s Sticky QGM QGP p Tc Tzb • pion, sigma masses go to zero at T = Tc;+: smooth phase transition (2nd order)

28. 2nd order phase transition Q: Can we make low-mass bound states above Tc ? We have only partial answers, but working on the problem

29. Our toy model (combined with lattice results) strong coupling regime ? Assumption thermal mass from lattice Klein-Gordon equation

30. Color Coulomb interaction • solve Klein-Gordon equation in relativistic regime

31. 4 -point Interaction (NJL type: Instantons ?) Lattice + NJL BGLR: Phys. Rep. 391 (2004) 353

32. 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

33. What the lattice free energy tell us ? in collaboration with F. Zantow (Bielefeld Group) Still on-going, but we are finding similar results

34. Potential extracted from Free energy [Bielefeld] closed : data open: fitting

35. Binding energy from 2-body potential Thermal mass dependence Bound state disappear

36. Mass of bound states with 2-body interaction Not enough binding yet !

37. 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 ? …….

38. 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 !

39. 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.