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Hydrodynamic Instability in the Quark-Gluon Plasma. Carlos E. Aguiar Instituto de Física - UFRJ. C.E.A., E.S. Fraga, T. Kodama, nucl-th/0306041. Outline : Introduction; explosive hadronization Thermodynamics of the chiral phase transition Supercooling and spinodal decomposition
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Hydrodynamic Instabilityin the Quark-Gluon Plasma Carlos E. Aguiar Instituto de Física - UFRJ C.E.A., E.S. Fraga, T. Kodama, nucl-th/0306041
Outline: • Introduction; explosive hadronization • Thermodynamics of the chiral phase transition • Supercooling and spinodal decomposition • Hydrodynamics of the chiral phase transition • Fluid mechanical instability in the QGP • Comments
t hadrons 10 fm/c z Heavy Ion Collisions at High Energies mixedphase QGP SPH calculation
RHIC SPS Explosive Hadronization? ___ strong 1st order ...... weak 1st order - - - crossover D. Zschiesche et al. Phys. Rev. C 65 (2002) 064902 • HBT radii: sudden emission
T crossover 150 MeV QGP supercooling Hadrons 922 MeV The Phase Diagram of Strongly Interacting Matter
RHIC SPS Lattice QCD and Freezeout States Z. Fodor and S. D. Katz, Phys. Lett. B 534 (2002) 87, JHEP 0203 (2002) 014
Thermodynamics of theChiral Phase Transition Linear sigma model
Partition function Effective potential • mean field approximation: <>
crossover 1st order Effective Potential
crossover 1st order Supercooling and Spinodal Decomposition
First order sh sc Pressure and Chiral Field
Mesons First order
Pressure and Chiral Field Crossover
Mesons Crossover
chiralsymmetry spinodal line broken chiralsymmetry Chiral Phase Diagram
broken symmetry chiral symmetry spinodal T-n Diagram
baryon number conservation entropy conservation flow velocity normalization constraints: Hydrodynamics of the Chiral Phase Transition Action:
Wave Motion Perturbation ofequilibrium: Linearizedequations:
Chiral and Sound Modes Dispersion relation Long wavelengths sound waves: chiral waves:
Hydrodynamic Instability If then s2 < 0, and the sound modes become unstable, growing exponentially instead of propagating. This instability occurs before the chiral spinodal line (m2 = 0) is reached. More importantly, the crossover region (m2 0) is unstable.
instabilityline spinodal Hydrodynamic Instability in the QGP
instabilityline Instability Line in the T-n Plane
In summary: • The nonequilibrium chiral condensate changes qualitatively the hydrodynamical behavior of the QGP • Explosive hadronization doesn’t need spinodal decomposition, and can occur even in the crossover region.
Final comments: • This is a very general effect; it doesn’t depend on specific aspects of the sigma model. • The instability develops even for very slow cooling, contrary to spinodal decomposition. • Finite size effects may be important in nuclei: min ~ 5 fm at the critical point • Implications for the hadronization process in: • heavy ion collisions (?) • early universe (!)