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@Nagoya. Infrared Slavery Above and Hadronic Freedom Below Tc. STAR rho^0/pi^- ratio. in collaboration mainly with G.E. Brown, Mannque Rho NPA 740 (2004) 171 (w/Shuryak) NPA 747 (2005) 530 nucl-th/0507073; PRC, accepted. Chang-Hwan Lee @. Our works on Exotic States in Hot & Dense Matter.
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@Nagoya Infrared Slavery Above and Hadronic Freedom Below Tc STAR rho^0/pi^- ratio in collaboration mainly with G.E. Brown, Mannque Rho NPA 740 (2004) 171 (w/Shuryak)NPA 747 (2005) 530nucl-th/0507073; PRC, accepted Chang-Hwan Lee @
Our works on Exotic States in Hot & Dense Matter RHIC T Astrophysics Hadrons Neutron Star K bound system Black Hole Density
Plan of Talk Below Tc : Chiral Symmetry Restoration Above Tc: colorless Mesonic Bound States • Brown/Rho Scaling • Vector Manifestation a la Harada/Yamawaki • What can we learn from lattice calculations ? • Implications for RHIC: STAR “rho^0/pi^-” ratio Scaling decay width & Delayed-decay of mesons
Below Tc: Chiral Symmetry Restoration • Dropping Masses a la Brown/Rho Scaling • Harada/Yamawaki & Harada/Sasaki/Rho Vector Manifestation. Fixed Point of RG approach gives vanishing coupling, vanishing mass towards chiral symmetry restoration point. both mass & decay-width scale !
Theoretical description of dropping r mass ? ☆ Vector Manifestation M.H. and K.Yamawaki, Phys. Rev. Lett. 86, 757 (2001) near chiral restoration point longitudinal r= Chiral partner of p Dropping r mass ・・・ necessary for the VM. ☆ Brown-Rho scaling implies dropping rmass ⇔ chiral symmetry restoration
Chiral Restoration vector manifestation linear sigma model mρ → 0 is necessary ・・・ support BR scaling
☆ Wilsonian matching at T → Tc - e • current correlators in the OPE ☆ Can we satisfy GV → GA in the HLS ?
mρ→ 0・・・ signal of the chiral symmetry restoration ! G.E.Brown and M.Rho, PRL 66, 2720 (1991) ☆ Is mr(T) → 0 related to the chiral symmetry restoration ? ◎ Wilsonian matching near Tc add the quantum and hadronic thermal corrections ◎ Quantum theory
below TcChiral Symmetry Restoration Vector Manifestation RG fixed point Vanishing coupling M r s RHIC p Tc Q) What happens above Tc ? Hadronization ?
What RHIC found • RHIC data is consistent with ideal hydrodynamics. • Matter formed at RHIC is not weakly interacting quasi-particle gas. • 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)
Global Chemical Equilibrium with high temperature ! T=165 ±10 MeV, STAR White paper, 2005
What happened at RHIC ? Hydrodynamical Expansion Elliptic Flow Hydrodynamical expansion of trapped Li6
(h/s = 0) Ideal Hydrodynamics • QCD: h/s » 1 • RHIC : h/s ≈ 0.1 • AdS/CFT : h/s ≈ 0.08 (Policastro, Son, Starinets) • much less than that of most liquids h/s=1 for He4 at high pressureh/s=40 for water
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 • sQGP, Quark-Gluon-Liquid
Mesonic bound states above Tc: • Hatsuda & Kunihiro, PRL 55 (1985) 158(para pion & sigma)Asakawa, Hatsuda, & Nakahara, NPA 715 (2003) 863cBrown, Lee, Rho, & Shuryak, NPA 740 (2004) 171Quark-antiquark bound states exists above Tc. - Kitazawa, Kunihiro, Nemoto
Potential from Bielefeld Lattice Results cf) Wong, hep-ph/0408020; combination of V & F What is the binding energy if we take the potential extracted from lattice free energy ? Assumption: finite value of V1 at r=∞ is absorbed into the renormalized thermal mass of quarks.
Above Tc: Running coupling at large diatance Strong coupling regime above Tc Lattice Calculation by F. Zantow et al. (Bielefeld)
Heavy quark potential (renormalized) from Bielefeld lattice mq=1.4 GeV
Mass of Bound States (with heavy quark potential) thermal quark mass Solid lines are just to guide you.
Modification for light quarks in chiral limit color-magnetic effects (cf K-electron) a =velocity of particles (c=1 unit) With chirally restored u, d quarks (helicity eigenstates) 32 degrees of freedom (including plasmino) = lattice result 32 above Tc !
Effective degrees of freedom [Karsch et al.] Idea gas limit staggered fermions Effective degrees of freedom is lower by 20% from ideal gas limit (massless limit). 32 istead of 37 (ideal gas limit)
heavy quark potential chiral limit heavy quark potential chiral limit
Unorthodox phase structure (Hypothesis) 2mq* a1 M r Mesons disappear qq s Ideal Liquid QGP p Tc Tzb • Masses of colorless pion, sigma-like modes above Tc go to zero at T = Tc;+
Lattice Results from Miller: Gluon Condensate Soft glue Hard glue is responsible for ldeal liquid Hard glue
Implications for RHIC Scaling decay width (nucl-th/0507073) Vector manifestation by Harada & Yamawaki No decay near Tc ! dominant decay is around & below T=120 MeV
Braun-Munzinger, Stachel, Wetterich (2003) • Chemical freezeout temperature is close to Tc. • Equilibration in the chirally broken sector just below Tc. • Puzzle: “r/p” 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 ! ]
STAR: Peripheral collisions: Tchemical freeze out = Tc PRL 92 (2004) 092301 Tc : chemical equilibrium Delayed decay of rho at T=120 MeV Equilibrium is already established above Tc at RHIC
Rough counting 32 d.o.f. can produce roughly 60 p’s (including r, a1, s decay, etc) 19 p- With massless mesonic bound states at Tcthis ratio is governed mainly by degrees of freedom 3 (r0) = 0.15 20 (pi- from s & r, …)
Peripheral collisions: Tchemical freeze out = Tc 4 x 10-4 with vacuum mass( Braun-Munzinger et al. ) With massless mesonic bound states at Tcthis ratio is governed mainly by degrees of freedom 3 (r0) = 0.16 19 (pi- from s & r, …) [ nucl-th/0507073, PRC, accepted]
Conclusions • Our analysis (chiral symmetry restoration + Bielefeld Lattice Result) indicates masslessmesonic bound states at Tc;+. • mass & width (simultaneous scaling):delayed rho decay is consistent with rho/pi ratio in peripheral collisions in STAR. Thanks to Bielefeld Lattice Group (F. Zantow) for providing us their results.
Lots to be done. • Problem of Hadronization through Tc :continuity of hadronic degrees of freedom • HBT puzzle • Clear signal of chiral symmetry restoration at RHIC? • …… Thanks !