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Recent Results from NA49

Christoph Blume. XXXXth Rencontres de Moriond QCD and High Energy Hadronic Interactions March 12-19, 2005. Recent Results from NA49. Critical point. 1st order. Cross over. Heavy Ion Physics at the CERN SPS Exploring the QCD Phase Diagram.

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Recent Results from NA49

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  1. Christoph Blume XXXXth Rencontres de Moriond QCD and High Energy Hadronic Interactions March 12-19, 2005 Recent Results from NA49

  2. Critical point 1st order Cross over Heavy Ion Physics at the CERN SPSExploring the QCD Phase Diagram • SPS energy regime allows to explore an essential part of the phase diagram: • Chemical freeze-out points approach phase boundary at SPS energies • Transition to QGP is likely to happen in this region • Ebeam = 20 - 158 AGeV (sNN = 6.3 - 17.3 GeV) • Use hadronic observables to pin down phase transition • Systematic studies required:  Energy dependence Lattice calculations: Fodor and Katz Bielefeld-Swansea group Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  3. 13m Heavy Ion Physics at the CERN SPS The NA49 Experiment Particle identification: Pions,charged Kaons: dEdx in TPCs + TOF (mid-rapidity) K0s, , , : Decay topology + invariant mass : Invariant mass of identified Kaons Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  4. Outline • Energy dependence • Rapidity spectra • Transverse mass spectra • 4 particle yields • Event-by-event fluctuations • Energy dependence of K/ fluctuations • System size dependence of multiplicity fluctuations • Elliptic flow of Lambdas • Outlook: “High”-pt at the SPS • Identified particle spectra at high pt Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  5. Rapidity Spectra Central Pb+Pb 7% (20-80) 5/10% (158) Change of shape only for L Others: ~ Gaussians Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  6. Rapidity SpectraEnergy Dependence of Widths Linear dependence on ybeam (works up to RHIC !) Clear hierarchy for Gaussian-like particles at SPS (p, ,  excluded):  > K+ > K-,  >  Seems to break down at AGS  Thermal component of longitudinal flow Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  7. Transverse Mass SpectraEnergy Dependence of mt-m0  negatively charged Energy dependence of transverse activity seems to change around 30 AGeV. General feature for pion, kaons and protons Cannot easily be reproduced by hadronic models (UrQMD, HSD)  Change of EOS ? Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  8. / K+/+ -/ K-/- / -++/ Particle YieldsEnergy Dependence + Statistical Model Statistical hadron gas model: s = 1 P. Braun-Munzinger, J. Cleymans, H. Oeschler, and K. Redlich Nucl. Phys. A697 (2002) 902 Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  9. / K+/+ -/ K-/- / -++/ Particle YieldsEnergy Dependence + Transport Models UrQMD HSD E.L. Bratkovskaya et al., PRC 69 (2004), 054907 Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  10. 160 GeV preliminary 20 GeV preliminary s= RMS/Mean * 100 [%] s2dynamic = s2data - s2mix FluctuationsParticle Ratios Event-by-event fluctuations of e.g. K/ • Compare to mixed event • reference • Resolution • Finite number statistics NA49  Extraction of dynamical fluctuations NA49 Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  11. FluctuationsEnergy Dependence of K/p Fluctuations Data wider than mixed events reference Clear energy dependence of K/p fluctuations observed  Decrease with energy Fluctuation from UrQMD independent of energy Non-zero value due to energy and strangeness conservation preliminary Promising, but no clear evidence for critical point yet Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  12. Normalized variance: for Poisson FluctuationsSystem Size Dependence of Multiplicity Fl. Correction for finite width of interval DEPS and resolution of calorimeter Strong centrality dependence with maximum around Nw (2NpProj) = 70 forward rapidities 4.0 < yp < 5.5 Effect not seen in HIJING model Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  13. Elliptic FlowEnergy Dependence of Lambda v2(pt) Initial spatial anisotropy  different pressure gradients  momentum anisotropy v2 preliminary Lambda v2 seems to be significantly lower at SPS than at RHIC Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  14. No quark number scaling (recombination) observed? Elliptic FlowParticle Type Dependence v2 for Lambdas seems to be lower than for protons (caveat: different centrality selection) preliminary Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  15. -, K-, p Identified particle spectra for , K, K0s, p, p,   p/-, /K0s-ratios and Rcp up to pt = 4GeV (but no RAA !) Outlook“High”-pt at the SPS • Very little information • about “high”-pt (> 2 GeV) • in heavy ion reactions at • SPS energies so far • Jet-quenching observable? • Parton coalescence? • Cronin effect charged particles 2.91 <  < 3.51 Pb+Pb 158 AGeV very perliminary central peripheral identified particles 2.91 <  < 3.51 Pb+Pb 158 AGeV very perliminary Andras Laszlo Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  16. Summary • Systematic study of sdependence of hadronic observables: • Mass dependence of rapidity widths • Change of the energy dependence of mt-spectra at 30 AGeV  Evidence for phase transition ? • Maximum in the strangeness to pion ratio at 30 AGeV  Evidence for deconfinement ? • Fluctuations • Significant increase of K/ fluctuations towards lower energies • Strong centrality dependence of multiplicity fluctuations • No direct understanding yet, but encouraging (critial point !) • Measurement of Lambda flow • Quark number scaling not observed ? • Consistent with hydro ? • Outlook • pt-spectra of identified particles at high pt Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  17. The NA49 Collaboration C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Bialkowska, C. Blume, B. Boimska, M. Botje, J. Bracinik, R. Bramm, R. Brun, P. Buncic, V. Cerny, P. Christakoglou, O. Chvala, J.G. Cramer, P. Csató, P. Dinkelaker, V. Eckhardt, D. Flierl, Z. Fodor, P. Foka, V. Friese, J. Gál, M. Gazdzicki, V. Genchev, G. Georgopoulos, E. Gladysz, K. Grebieszkow, S. Hegyi, C. Höhne, K. Kadija, A. Karev, M. Kliemant, S. Kniege, V.I. Kolesnikov, E. Kornas, R. Korus, M. Kowalski, I. Kraus, M. Kreps, M. van Leeuwen, P. Lévai, L. Litov, B. Lungwitz, M. Makariev, A.I. Malakhov, M. Mateev, G.L. Melkumov, M. Mitrovski, J. Molnár, S. Mrowczynski, V. Nicolic, G. Pálla, A.D. Panagiotou, D. Panayotov, A. Petridis, M. Pikna, D. Prindle, F. Pühlhofer, R. Renfordt, C. Roland, G. Roland, M. Rybczynski, A. Rybicki, A. Sandoval, N. Schmitz, T. Schuster, P. Seyboth, F. Siklér, B. Sitar, E. Skrzypczak, G. Stefanek, R. Stock, H. Ströbele, T. Susa, I. Szentpétery, J. Sziklai, P. Szymanski, V. Trubnikov, D. Varga, M. Vassiliou, G.I. Veres, G. Vesztergombi, D. Vranic, A. Wetzler, Z. Wlodarczyk, I.K. Yoo, and J. Zimányi Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  18. The End Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  19. Heavy Ion Physics at the CERN SPSParticle Identification in NA49 • dE/dx measured in TPCs • Large acceptance • Resolution 3-4% • Time-of-flight • Mid-rapidity • Resolution 60 ps Example: Pb+Pb @ 40 AGeV Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  20. Rapidity SpectraEnergy Dependence of Widths Pion widths are close to Landau prediction, but not perfectly But: Perfect agreement to linear dependence on ybeam Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  21. Rapidity SpectraMass Dependence of Widths  negatives Approx. linear dependence on particle mass Similar slope at all SPS energies  Thermal component of longitudinal flow Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  22. Transverse Mass SpectraInverse Slope Parameters of Kaons Step in energy dependence Seems to be absent in p+p How about other particle types? p+p compilation from: M. Kliemant, B. Lungwitz, and M. Gazdzicki, PRC 69 (2004) 044903 Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  23. s-quark carriers: K-, K0(1)  (incl. 0) 0,-, - (2) ±(3) s-quark carriers: K+, K0(1)  (incl. 0) 0,+, + (2) ±(3) (1)K0  K+, K0  K- by isospin symmetry (2)Taken from hadron gas fit by F. Becattini et al., if not measured. (3)Empirical factor ( + ) /  = 1.6 assumed. Energy dependence of strangeness production changes at  30 AGeV Particle YieldsComparison s- and s-Carriers Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  24. Maximum in strangeness/pion ratio Same for s and s quarks Particle Yields(Anti-)Strangeness to Pion Ratio Difficult to model Solid line: Statistical hadron gas model with s = 1 K. Redlich, priv. comm. Predicted as signal for the onset of deconfinement M. Gazdzicki and M.I. Gorenstein, Acta Phys. Polon. B30 (1999), 2705 Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  25. FluctuationsThe Critical Point Endpoint of the first order phase transition line  crossover on left side Position quite uncertain But recent lattice calculations by Fodor and Katz predicts position at B = 360 MeV using physical quark masses It might be accessible in the SPS energy range Observables:Event-by-event fluctuations Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  26. FluctuationsEnergy Dependence of p/p Fluctuations • Data narrower than reference • Can be caused by resonances Clear energy dependence of p/p fluctuations observed  Increase with energy preliminary • Similar trend seen in UrQMD • Resonance contribution changes with beam energy Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

  27. Elliptic FlowLambda Flow Event plane from pions Flattening of accepttance via event plane shifting Corrected for event plane resolution S/B = 5-11 Christoph Blume XXXXth Rencontres de Moriond, March 12-19 2005

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