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Bulk Properties of QCD Matter

Bulk Properties of QCD Matter. Many thanks to organizers !. Kai Schweda, University of Heidelberg / GSI Darmstadt. Outline. Introduction Hadron Abundances - T ch Collective Flow - T fo ,  Heavy Quarks - open charm and quarkonia. Introduction. Quark Gluon Plasma.

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Bulk Properties of QCD Matter

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  1. Bulk Properties of QCD Matter Many thanks to organizers ! Kai Schweda, University of Heidelberg / GSI Darmstadt

  2. Outline • Introduction • Hadron Abundances - Tch • Collective Flow - Tfo,  • Heavy Quarks - open charm and quarkonia

  3. Introduction

  4. Quark Gluon Plasma Source: Michael Turner, National Geographic (1996) • Quark Gluon Plasma: • Deconfined and • thermalized state of quarks and gluons •  Study partonic EOS at RHIC and LHC(?) Probe thermalization using heavy-quarks

  5. Heavy quarks with ALICE at LHC: - Study medium properties - pQCD in hot and dense environment • FAIR/GSI program: - Search for the possible phase boundary. - Chiral symmetry restoration Nuclear phase diagram Energy scan

  6. Colliding Heavy Nuclei

  7. High-Energy Nuclear Collisions Time  • 1) Initial condition: 2) System evolves: 3) Bulk freeze-out • Baryon transfer - parton/hadron expansion - hadronic dof • - ET production - inel. interactions cease: • Partonic dof particle ratios, Tch, mB • - elas. interactions cease • Particle spectra, Tth, <bT> Plot: Steffen A. Bass, Duke University

  8. Collision Geometry z Au + Au sNN = 200 GeV x Non-central Collisions Uncorrected Number of participants:number of incoming nucleons in the overlap region Number of binary collisions:number of inelastic nucleon-nucleon collisions Charged particle multiplicity collision centrality Reaction plane: x-z plane

  9. Hadron Abundances

  10. Particle Multilplicities PHOBOS fit HIJING BBar Armesto et al. AMPT Eskola CGC KLN ASW DPMJET-III EHNRR • at LHC, dN/dh 1000 - 3000 • estimate energy density PHOBOS compilation: W. Busza, SQM07. Theory points: HI at LHC – last call for predictions, CERN, May 2007.

  11. EoS from Lattice QCD • 1) Large increase in  ! • Large increase in Ndof: Hadrons vs. partons 2) TC~ 160 MeV 3) Boxes indicate max. initial temperatures • Longest expansion duration at LHC • Expect large partonic collectivity at LHC SPS RHIC LHC ? Z. Fodor et al, JHEP 0203:014(02) C.R. Allton et al, hep-lat/0204010 F. Karsch, Nucl. Phys. A698, 199c(02).

  12. HI - Collision History • Tc(ritical): quarks and gluon hadrons, Tc(ritical) = 160 MeV • Tch(emical): hadron abundancies freeze out • Tfo: particle spectra freeze out Plot: R. Stock, arXiv:0807.1610 [nucl-ex].

  13. Solar Spectrum Wavelength and Intensity solely determined by temperature Tsolar = 5500 °C(at the sun’s surface) Graphik: Max-Plack-Institut für Plasmaphysik

  14. Wie heiss ist die Quelle ? 1000 • Lichtquelle  Teilchenquelle • Häufigkeit von Teilchen am besten beschrieben durch T = 2 000 000 000 000 C = 2 Trillionen C  100 000 mal heisser als im Innern der Sonne ! p N K+ 100. L K0 K- h Teilchenhäufigkeit N X 10.0 f L W 1.0 X W 0.1 0 0.4 0.8 1.2 1.6 E = mc2 (GeV)

  15. Chemical Freeze-out Model Refs. J.Rafelski PLB(1991)333 P. Braun-Munzinger et al., nucl-th/0304013 Hadron resonance ideal gas Density of particle i Qi : 1 for u and d, -1 for u and d si : 1 for s, -1 for s gi:spin-isospin freedom mi : particle mass Tch : Chemical freeze-out temperature mq : light-quark chemical potential ms : strange-quark chemical potential V : volume term, drops out for ratios! gs : strangeness under-saturation factor mB = 3mq mS = mq-ms All resonances and unstable particles are decayed Compare particle ratios to experimental data

  16. Hadron Yield - Ratios 1) At RHIC: Tch = 160 ± 10 MeV B = 25 ± 5 MeV 2) S= 1.  The hadronic system is thermalized at RHIC. 3)Short-lived resonances show deviations.  There is life after chemical freeze-out. RHIC white papers - 2005, Nucl. Phys. A757, STAR: p102; PHENIX: p184; Statistical Model calculations: P. Braun-Munzinger et al. nucl-th/0304013.

  17. Chemical Freeze-Out vs Energy • With increasing energy: • Tch increases and saturatesat Tch = 160 MeV • Coincides with Hagedorn temperature • Coincides with early lattice results limiting temperature for hadrons, Tch 160 MeV ! • mB decreases, mB = 1MeV at LHC •  Nearly net-baryon free ! A. Andronic et al., NPA 772 (2006) 167.

  18. QCD Phase Diagram

  19. Baryon Ratios • With increasing energy: • Baryon ratios approach unity • At LHC, pbar / p  0.95 with increasing collision energy, production of matter and anti-matter gets closer Compilation: N. Xu

  20. ‘Elementary’ p+p Collisions • Low multiplicities  use canonical ensemble:Strangeness locally conserved! • particle yields are well reproduced • Strangeness not equilibrated ! (gs = 0.5) Statistical Model Fit: F. Becattini and U. Heinz, Z. Phys. C 76, 269 (1997).

  21. HI - Collision History • Tc(ritical): quarks and gluon hadrons, Tc(ritical) = 160 MeV • Tch(emical): hadron abundancies freeze out, Tch(emical) = 160 MeV • Tfo: particle spectra freeze out Plot: R. Stock, arXiv:0807.1610 [nucl-ex].

  22. Collective Flow

  23. Pressure, Flow, … • Thermodynamic identity • – entropy p – pressure U – energy V – volume t = kBT, thermal energy per dof • In A+A collisions, interactions among constituentsand density distribution lead to: pressure gradient  collective flow • number of degrees of freedom (dof) • Equation of State (EOS) • cumulative – partonic + hadronic

  24. Typical mass ordering in inverse slope from light  to heavier Two-parameter fit describes yields ofp, K, p, L Tth = 90  10 MeV <bt> = 0.55  0.08 c  Disentangle collective motion from thermal random walk Momentum Distributions* Tth=107±8 [MeV] <bt>=0.55±0.08 [c] n=0.65±0.09 2/dof=106/90 ] c)-1 [(GeV/ solid lines: fit range dy N T dp d p 2 p p K (dE/dx) K (kink) p K (dE/dx) K (kink) p L L 2 *Au+Au @130 GeV, STAR

  25. (anti-)Protons From RHIC Au+Au@130GeV More central collisions Centrality dependence: - spectra at low momentum de-populated, become flatter at larger momentum stronger collective flow in more central coll.! STAR: Phys. Rev. C70, 041901(R).

  26. Thermal Model + Radial Flow Fit • Source is assumed to be: • in local thermal equilibration: Tfo • boosted in transverse radial direction: r = f(bs) boosted E.Schnedermann, J.Sollfrank, and U.Heinz, Phys. Rev. C48, 2462(1993) random

  27. D-meson collective flow Large collective flow velocity  Spectrum moves to larger momentum

  28. HI - Collision History • Tc(ritical): quarks and gluon hadrons, Tc(ritical) = 160 MeV • Tch(emical): hadron abundancies freeze out, Tch(emical) = 160 MeV • Tfo: particle spectra freeze out, Tfo 100 MeV :, K, p Plot: R. Stock, arXiv:0807.1610 [nucl-ex].

  29. Kinetic Freeze-out at RHIC 1) Multi-strange hadrons  and  freeze-out earlier than (p, K, p)  Collectivity prior to hadronization 2) Sudden single freeze-out*: Resonance decays lower Tfo for (p, K, p)  Collectivity prior to hadronization Partonic Collectivity ? STAR Preliminary STAR Data: Nucl. Phys. A757, (2005 102), *A. Baran, W. Broniowski and W. Florkowski, Acta. Phys. Polon. B 35 (2004) 779.

  30. Anisotropy Parameter v2 coordinate-space-anisotropy  momentum-space-anisotropy y py px x Initial/final conditions, EoS, degrees of freedom

  31. v2 in the Low-pT Region P. Huovinen, private communications, 2004 • v2 approx. linear in pT, mass ordering from light  to heavier  • characteristic of hydrodynamic flow ! • sensitive to equation of state

  32. Non-ideal Hydro-dynamics • finite shear viscosity reduces elliptic flow • many caveats, e.g.: - initial eccentricity  (Glauber, CGC, …) - equation of state - hadronic contribution to /s String theory predicts: /s > 1/4 M.Luzum and R. Romatschke, PRC 78 034915 (2008); P. Romatschke, arXiv:0902.3663.

  33. Elliptic Flow vs Collision Energy Glauber initial conditions • Centrality dependence:- initial eccentricity - overlap area S • Collision energy dep.:- multiplicity density dNch/dy • in central collisions at RHIC, hydro-limit seems reached ! NA49, Phys. Rev. C68, 034903 (2003);STAR, Phys. Rev. C66, 034904 (2002);Hydro-calcs.: P. Kolb, J. Sollfrank, and U. Heinz, Phys. Rev.C62, 054909 (2000).

  34. v2 of  and multi-strange  • Strange-quark flow - partonic collectivity at RHIC ! QM05 conference: M. Oldenburg; nucl-ex/0510026.

  35. Collectivity, Deconfinement at RHIC - v2, spectra of light hadrons and multi-strange hadrons - scaling with the number of constituent quarks At RHIC, it seems we have:  Partonic Collectivity • Deconfinement  Thermalization ? • PHENIX: PRL91, 182301(03) • STAR: PRL92, 052302(04) • S. Voloshin, NPA715, 379(03) • Models: Greco et al, PRC68, 034904(03) • X. Dong, et al., Phys. Lett. B597, 328(04). • ….

  36. Collectivity - Energy Dependence • Collectivity parameters <bT> and <v2> increase with collision energy • strong collective expansion at RHIC !<bT>RHIC 0.6 • expect strong partonic expansion at LHC, <bT>LHC 0.8, Tfo Tch K.S., ISMD07, arXiv:0801.1436[nucl-ex].

  37. Partonic Collectivity at RHIC • 1) Copiously produced hadrons freeze-out p,K,p: • Tfo = 100 MeV, T = 0.6 (c) > T(SPS) • 2)Multi-strange hadrons freeze-out: • Tfo = 160-170 MeV (~ Tch), T = 0.4 (c) • 3)Multi-strange v2: • f and multi-strange hadrons  and  do flow! • 4) Model - dependent /s: (0?),1 - 10 x 1/4 • Deconfinement & • Partonic (u,d,s) Collectivity!

  38. Heavy Quarks

  39. mc,b>> QCD : new scale • mc,b const., mu,d,s ≠ const. • initial conditions:  test pQCD, R, F probe gluon distribution • early partonic stage: diffusion (), drag (), flow probe thermalization • hadronization: chiral symmetry restoration confinement statistical coalescence J/ enhancement / suppression Heavy  flavor: a unique probe Q2 X. Zhu, M. Bleicher, S.L. Huang, K.S., H. Stöcker,N. Xu, and P. Zhuang, PLB 647 (2007) 366. time

  40. Limitations in PDFs • Most charm created from gluons, e.g. g+g  c + cbar • increasing uncertainties in gluon distribution at smaller Bjorken x: • Assume y=0, pT=0, x1=x2 • 2 x mcharm 3 GeVRHIC (s=0.2TeV): x = 0.015LHC (s=14TeV): x = 2x10-4

  41. Heavy  Quark Production Heavy-quark production at LHC, compared to RHIC expect factors Charm  10 Beauty  100 (i) Heavy-quarks abundantly produced at LHC energies ! (ii) Large theoretical uncertainties  energy scan (LHC,FAIR) will help ! Plots: R. Vogt,Eur. Phys. J. C, s10052-008-0809-x (2008).

  42. Heavy  quark Correlations • c-cbar mesons are correlated • Pair creation: back to back • Gluon splitting: forward • Flavor excitation: flat • Exhibits strong correlations ! • Baseline at zero: clear measure ofvanishing correlations !  probe thermalization among partons ! PYTHIA: p + p @ 14 TeV X. Zhu, M. Bleicher, S.L. Huang, K.S., H. Stöcker,N. Xu, and P. Zhuang, PLB 647 (2007) 366. G. Tsildeakis, H. Appelshäuser, K.S., J. Stachel, arXiv: 0908.0427.

  43. How to measure Heavy-Quark Production • e.g., D0, c = 123 m • displaced decay vertex is signature of heavy-quark decay • need precise pointing to collision vertex

  44. Heavy  Flavor production at RHIC • large discrepancy between STAR and PHENIX: factor > 2 (!) • need Si-vertex upgrades(> 2011) • large theoretical uncertainties (factor > 10) • Measure charm production at RHIC, LHC, FAIR and provide input to theory: - gluon distribution, - scales R, F Plot: J. Dunlop (STAR), QM2009, Open Heavy-flavor in heavy-ion collisions, Calcs: R. Vogt,Eur. Phys. J. C, s10052-008-0809-x (2008), M. Cacciari, 417th Heraeus Seminar, Bad Honnef (2008).

  45. Where does all the charm go? J c Ds D0 D • Total charm cross section: open charm hadrons,e.g. D0, D*, Lc, … or c,b  e() + X • Hidden-charm mesons, e.g. J/y carry ~ 1 % of total charm Statistics plot: H. Yang and Y. Wang, U Heidelberg.

  46. D0 p+ + K- Reconstruction p+ K- D0, ct = 123 mm Plot: A. Shabetai

  47. Open  Charm Performance • Measure secondary decay vertex  Direct reconstruction of D0 address heavy-quark production with 1st year of data taking • Many other channels, e.g. D+, D* • Also: single-electrons from heavy-flavor decays ALICE: PPR.vol.II, J. Phys. G 32 (2006) 1295. Simulation: 109 p+p, 108 p+Pb, 107 Pb+Pb collisions

  48. D* meson Identification • D*+ D0 + + • Identify D*+throughM[D*+ - D0] • Subtract resonance decay to D0 • Two different methods to address total charm production D*± analysis: Yifei Wang, Ph.D. thesis, University of Heidelberg, in preparation.

  49. Viele neue interessante Signale in ALICE bei LHC:z.B. Hadronen mit schweren Quarks (charm und beauty) D0, D+, D*, Ds, J/y, y’, Lc,Lb,

  50. Quarkonia

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