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Behind QGP

Behind QGP. 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. Máté Csanád, Eötvös University Budapest

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Behind QGP

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  1. Behind QGP 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 Máté Csanád, Eötvös University Budapest ISSP’06, August 29 – September 7, Erice Exploring the properties of the QCD Matter

  2. 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/

  3. 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 ~ 170MeV  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

  4. Elliptic flow: v2 • Second Fourier coefficient of pt-spectra in transverse plane angle • Gas, no interaction: spherical symmetry, v2 = 0 • Hydrodynamic, collective behavior: v2 > 0 • Fluid dynamics describes v2 M. Csanád, T. Csörgő, A. Ster et al. nucl-th/0512078

  5. 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

  6. Advanced e0 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 /t0  15 usually

  7. Advanced e0 estimate • Fits to BRAHMS dn/dh data: l  2 • Correction factors of e0/eBj 2.0 – 2.2 • Inital energy density of e0 ~ 10 – 30 GeV/fm3

  8. Csanád, Csörgő, Ster, nucl-th/0310040, nucl-th/0311102, nucl-th/0403074 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! v2 spectra v2 spectra

  9. I1/I0 Universal hydro scaling of v2 • Buda-Lund hydro: prediction of scale function I1/I0 (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. C67, 034904, 2003) Csanád, Csörgő, Lörstad, Ster (Nucl. Phys. A742:80-94,2004) Csanád, Csörgő, Lörstad, Ster et al. nucl-th/0512078

  10. Scaling and scaling violations • Universal hydro scaling breaks • VALENCE QUARK number scaling sets in • Fluid of QUARKS!! PHENIX Collaboration, nucl-ex/0608033

  11. NA44, S+Pb 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, McLerran Phys.Rev.D53:5028-5033,1996 Z. Huang, X-N. Wang Phys.Rev.D53(1996)5034 Vance, Csörgő Kharzeev Phys.Rev.Lett.81:2205-2208,1998

  12. Why the l(mt) dependence Prediction: In hot and dense matter h’ mass reduction  Enhanced h’ content Decay: h’h+p+ +p-(p0+p++p−)+p++p− Long lifetime Average pt of p’s 138 MeV  More non-interacting p’s at 138 MeV l(mt) measures ratio of interacting p’s  A hole in l(mt) l(mt) measures fraction of interacting p’s PHENIX FINAL DATA Au+Au 200 GeV S. S. Adler et al., PRL93,152302(2004)

  13. 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

  14. 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 lQCD • 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…

  15. 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

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