Behind QGP Mt Csand Etvs University Budapest ISSP
Behind QGP Máté Csanád, Eötvös University Budapest ISSP’ 06, August 29 – September 7, Erice Exploring the properties of the QCD Matter • • • Investigating the matter of the early Universe Is the form of this matter Quark Gluon Plasma? What energy density, temperature? Evidence for a Quark Fluid instead of a QGP Further properties of the matter
Discovering new laws of Nature "In general we look for a new law by the following process. First we guess it. Then we compare the consequences of the guess to see what would be implied if this law that we guessed is right. Then we compare the result of the computation to nature, with experiment or experience, compare it directly with observation, to see if it works. If it disagrees with experiment it is wrong. In that simple statement is the key to science. It does not make any difference how beautiful your guess is. It does not make any difference how smart you are, who made the guess, or what his name is — if it disagrees with experiment it is wrong. ” /R. P. Feynman/ M. Csanád, ISSP’ 06 Erice 2
How did the Universe look like? • Expectation: Quark Gluon Plasma • Form of matter? • Plasma? Gas? Fluid? • Degrees of freedom? • Quarks and gluons? • Energy, temperature? • Lattice QCD: deconfined above ~ 170 Me. V 2 terakelvin • We will see: rather Quark Fluid than QGP • Metaphor or frozen world Theoretically predicted other forms of ice • Experiment: smash ice to ice, detect re-frozen ice-particles • • A lot predictions or guesses based on QGP failed M. Csanád, ISSP’ 06 Erice 3
Elliptic flow: v 2 • Second Fourier coefficient of pt-spectra in transverse plane angle • Gas, no interaction: spherical symmetry, v 2 = 0 • Hydrodynamic, collective behavior: v 2 >0 • Fluid dynamics describes v 2 M. Csanád, T. Csörgő, A. Ster et al. nucl-th/0512078 M. Csanád, ISSP’ 06 Erice 4
Relativistic Perfect Fluids • Success of hydro models Elliptic flow • Hydro scaling of spectra slopes and correlation length’ • • A new family of exact solutions: • T. Csörgő, M. I. Nagy, M. Csanád: nucl-th/0605070 • Two improvement to the Bjorken solution: Finite Rapidity distribution ~ Landau’s solution • Relativistic acceleration • Velocity field Number density Temperature M. Csanád, ISSP’ 06 Erice 5
Advanced e 0 estimate • Width of dn/dh distribution is due to acceleration, controlled by parameter l • Acceleration yields longitudinal explosion • Bjorken estimate underestimates initial energy density Here tf /t 0 15 usually M. Csanád, ISSP’ 06 Erice 6
Advanced e 0 estimate • Fits to BRAHMS dn/dh data: l 2 • Correction factors of e 0/e. Bj 2. 0 – 2. 2 • Inital energy density of e 0 ~ 10 – 30 Ge. V/fm 3 M. Csanád, ISSP’ 06 Erice 7
Temperature estimate • Buda-Lund hydro model compared to the data (fits) • At freeze-out, 1/8 of the volume above deconfinement temperature • At this high temperature: not gas, but fluid! v 2 spectra Csanád, Csörgő, Ster, nucl-th/0310040, nucl-th/0311102, nucl-th/0403074 M. Csanád, ISSP’ 06 Erice 8
Universal hydro scaling of v 2 I 1/I 0 • Buda-Lund hydro: prediction of scale function I 1/I 0 (2003, 2004) • PHENIX (2005), PHOBOS (2006) and STAR (2005) data do collapse • Prediction based on perfect hydro is VALID Csörgő, Akkelin, Hama, Lukács, Sinyukov (Phys. Rev. C 67, 034904, 2003) Csanád, Csörgő, Lörstad, Ster (Nucl. Phys. A 742: 80 -94, 2004) Csanád, Csörgő, Lörstad, Ster et al. nucl-th/0512078 M. Csanád, ISSP’ 06 Erice 9
Scaling and scaling violations • • • Universal hydro scaling breaks VALENCE QUARK number scaling sets in Fluid of QUARKS!! PHENIX Collaboration, nucl-ex/0608033 M. Csanád, ISSP’ 06 Erice 10
Chiral symmetry restoration? • Prediction: h’ mass reduction in hot and dense matter due to UA(1) symmetry restoration • Idea: measure l(mt) dependence at low momenta Kapusta, Kharzeev, Mc. Lerran Phys. Rev. D 53: 5028 -5033, 1996 Z. Huang, X-N. Wang Phys. Rev. D 53(1996)5034 Vance, Csörgő Kharzeev Phys. Rev. Lett. 81: 2205 -2208, 1998 M. Csanád, ISSP’ 06 Erice NA 44, S+Pb 11
Why the l(mt) dependence Prediction: In hot and dense matter h’ mass reduction Enhanced h’ content Decay: h’ h+p+ +p- (p 0+p++p−)+p++p− Long lifetime Average pt of p’s 138 Me. V More non-interacting p’s at 138 Me. V l(mt) measures ratio of interacting p’s A hole in l(mt) M. Csanád, ISSP’ 06 Erice l(mt) measures fraction of interacting p’s PHENIX FINAL DATA Au+Au 200 Ge. V S. S. Adler et al. , PRL 93, 152302(2004) 12
Analysis of new, low pt data • UA(1) restoration tested Results critically dependent on understanding of statistical and systematic errors • Additional analysis required for definitive statement • M. Csanád for the PHENIX Collaboration, Quark Matter 2005, Budapest nucl-ex/0509042 PHENIX PRELIMINARY M. Csanád, ISSP’ 06 Erice 13
What matter do we see? • We see a perfect fluid Elliptic flow: hydro signal • Broad range success of hydro models • • It is deconfined • High enough temperatures based on l. QCD • Degrees of freedom: quarks • Valence quark number scaling complimentary to hydro scaling • Signal of partial symmetry restoration • Mass reduction of h’ (preliminary) • A lot more not covered here • Rare probes, penetrating probes, jet suppression… M. Csanád, ISSP’ 06 Erice 14
Where do we go? • Explore all properties of the Quark Matter Analyse more data • Make further guesses • Use higher luminosity • • Full map of the QCD phase diagram Go to higher energy • Compare to lower energy data • Use different colliding systems (e, p) • • Columbus has just arrived to the new world M. Csanád, ISSP’ 06 Erice 15
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