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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 1/62 Bulk Properties of QCD Matter Kai Schweda, University of Heidelberg / GSI Darmstadt Many thanks to organizers !
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 2/62 Outline Introduction Hadron Abundances - T ch Collective Flow - T fo, Heavy Quarks - open charm and quarkonia
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda Introduction
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 4/62 Source: Michael Turner, National Geographic (1996) Quark Gluon Plasma: (a)Deconfined and (b)thermalized state of quarks and gluons Study partonic EOS at RHIC and LHC (?) Probe thermalization using heavy-quarks Quark Gluon Plasma
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda Nuclear phase diagram 1)Heavy quarks with ALICE at LHC: - Study medium properties - pQCD in hot and dense environment 2)FAIR/GSI program: - Search for the possible phase boundary. - Chiral symmetry restoration Energy scan
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 6/62 Colliding Heavy Nuclei
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 7/62 High-Energy Nuclear Collisions 1) Initial condition:2) System evolves:3) Bulk freeze-out -Baryon transfer- parton/hadron expansion- hadronic dof - E T production- inel. interactions cease: -Partonic dof particle ratios, T ch, B - elas. interactions cease Particle spectra, T th, Time Plot: Steffen A. Bass, Duke University
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 8/62 Collision Geometry x z Non-central Collisions Au + Au s NN = 200 GeV 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
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda Hadron Abundances
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 10/62 Particle Multilplicities PHOBOS fit HIJING BBar Armesto et al. AMPT Eskola CGC KLN ASW DPMJET-III EHNRR at LHC, dN/d 1000 3000 estimate energy density Theory points: HI at LHC – last call for predictions, CERN, May 2007.PHOBOS compilation: W. Busza, SQM07.
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 11/62 EoS from Lattice QCD 1) Large increase in ! Large increase in Ndof: Hadrons vs. partons 2) T C ~ 160 MeV 3) Boxes indicate max. initial temperatures Longest expansion duration at LHC Expect large partonic collectivity at LHC Z. Fodor et al, JHEP 0203:014(02) C.R. Allton et al, hep-lat/0204010 F. Karsch, Nucl. Phys. A698, 199c(02). LHC ?RHICSPS
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 12/62 HI - Collision History Plot: R. Stock, arXiv:0807.1610 [nucl-ex]. T c(ritical) : quarks and gluon hadrons, T c(ritical) = 160 MeV T ch(emical) : hadron abundancies freeze out T fo : particle spectra freeze out
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 13/62 Graphik: Max-Plack-Institut für Plasmaphysik Wavelength and Intensity solely determined by temperature T solar = 5500 °C (at the sun’s surface) Solar Spectrum
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 14/62 N K+K+ K0K0 K-K- N E = mc 2 (GeV) Teilchenhäufigkeit 0.40.801.61.2 0.1 1.0 10.0 100. 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 ! Wie heiss ist die Quelle ?
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 15/62 Chemical Freeze-out Model Hadron resonance ideal gas Compare particle ratios to experimental data Q i : 1 for u and d, -1 for u and d s i : 1 for s, -1 for s g i : spin-isospin freedom m i : particle mass All resonances and unstable particles are decayed Refs. J.Rafelski PLB(1991)333 P. Braun-Munzinger et al., nucl-th/0304013 T ch : Chemical freeze-out temperature q : light-quark chemical potential s : strange-quark chemical potential V: volume term, drops out for ratios! s : strangeness under-saturation factor Density of particle i B = 3 q S = q - s
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda Hadron Yield Ratios 1) At RHIC: T ch = 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.
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 17/62 A. Andronic et al., NPA 772 (2006) 167. With increasing energy: T ch increases and saturates at T ch = 160 MeV Coincides with Hagedorn temperature Coincides with early lattice results limiting temperature for hadrons, T ch 160 MeV ! B decreases, B = 1MeV at LHC Nearly net-baryon free ! Chemical Freeze-Out vs Energy
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 18/62 QCD Phase Diagram
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 19/62 Baryon Ratios Compilation: N. Xu 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
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 20/62 ‘Elementary’ p+p Collisions Low multiplicities use canonical ensemble: Strangeness locally conserved! particle yields are well reproduced Strangeness not equilibrated ! ( s = 0.5) Statistical Model Fit: F. Becattini and U. Heinz, Z. Phys. C 76, 269 (1997).
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 21/62 HI - Collision History Plot: R. Stock, arXiv:0807.1610 [nucl-ex]. T c(ritical) : quarks and gluon hadrons, T c(ritical) = 160 MeV T ch(emical) : hadron abundancies freeze out, T ch(emical) = 160 MeV T fo : particle spectra freeze out
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda Collective Flow
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 23/62 Pressure, Flow, … Thermodynamic identity – entropy p – pressure U – energy V – volume = k B T, thermal energy per dof In A+A collisions, interactions among constituents and density distribution lead to: pressure gradient collective flow number of degrees of freedom (dof) Equation of State (EOS) cumulative – partonic + hadronic
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 24/62 Momentum Distributions* 2 ] [(GeV/ 2 c) -1 dy dp N d T K (dE/dx) p K (kink) *Au+Au @130 GeV, STAR T th =107±8 [MeV] =0.55±0.08 [c] n=0.65±0.09 2 /dof=106/90 solid lines: fit range Typical mass ordering in inverse slope from light to heavier Two-parameter fit describes yields of , K, p, T th = 90 10 MeV = 0.55 0.08 c Disentangle collective motion from thermal random walk K (dE/dx) p K (kink)
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 25/62 (anti-)Protons From RHIC Au+Au@130GeV (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).
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 26/62 Thermal Model + Radial Flow Fit Source is assumed to be: –in local thermal equilibration: T fo –boosted in transverse radial direction: = f( s ) random boosted E.Schnedermann, J.Sollfrank, and U.Heinz, Phys. Rev. C48, 2462(1993)
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 27/62 D-meson collective flow Large collective flow velocity Spectrum moves to larger momentum
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 28/62 HI - Collision History Plot: R. Stock, arXiv:0807.1610 [nucl-ex]. T c(ritical) : quarks and gluon hadrons, T c(ritical) = 160 MeV T ch(emical) : hadron abundancies freeze out, T ch(emical) = 160 MeV T fo : particle spectra freeze out, T fo 100 MeV : , K, p
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 29/62 1) Multi-strange hadrons and freeze-out earlier than ( , K, p) Collectivity prior to hadronization Collectivity prior to hadronization 2) Sudden single freeze-out*: Resonance decays lower T fo for ( , K, p) Collectivity prior to hadronization Partonic Collectivity ? Partonic Collectivity ? Kinetic Freeze-out at RHIC STAR Data: Nucl. Phys. A757, (2005 102), *A. Baran, W. Broniowski and W. Florkowski, Acta. Phys. Polon. B 35 (2004) 779. STAR Preliminary
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Anisotropy Parameter v 2 y x pypy pxpx coordinate-space-anisotropy momentum-space-anisotropy Initial/final conditions, EoS, degrees of freedom
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 31/62 v 2 in the Low-p T Region P. Huovinen, private communications, 2004 - v 2 approx. linear in p T, mass ordering from light to heavier àcharacteristic of hydrodynamic flow ! à sensitive to equation of state
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 32/62 Non-ideal Hydro-dynamics M.Luzum and R. Romatschke, PRC 78 034915 (2008); P. Romatschke, arXiv:0902.3663. 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
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 33/62 Elliptic Flow vs Collision Energy Centrality dependence: - initial eccentricity - overlap area S Collision energy dep.: - multiplicity density dN ch /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). Glauber initial conditions
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 34/62 v 2 of and multi-strange Strange-quark flow - partonic collectivity at RHIC ! QM05 conference: M. Oldenburg; nucl-ex/0510026.
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 35/62 Collectivity, Deconfinement at RHIC - v 2, spectra of light hadrons and multi-strange hadrons - scaling with the number of constituent quarks At RHIC, it seems we have: Partonic Collectivity êDeconfinement 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). ….
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 36/62 Collectivity Energy Dependence Collectivity parameters and increase with collision energy strong collective expansion at RHIC ! RHIC 0.6 expect strong partonic expansion at LHC, LHC 0.8, T fo T ch K.S., ISMD07, arXiv:0801.1436 [nucl-ex].
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 37/62 Partonic Collectivity at RHIC 1) Copiously produced hadrons freeze-out ,K,p: T fo = 100 MeV, T = 0.6 (c) > T (SPS) 2) Multi-strange hadrons freeze-out: T fo = 160-170 MeV (~ T ch ), T = 0.4 (c) 3) Multi-strange v 2 : and multi-strange hadrons and do flow! 4) Model - dependent /s: (0?),1 - 10 x 1/4 Deconfinement & Partonic (u,d,s) Collectivity !
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda Heavy Quarks
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda Heavy flavor: a unique probe X. Zhu, M. Bleicher, S.L. Huang, K.S., H. Stöcker, N. Xu, and P. Zhuang, PLB 647 (2007) 366. m c,b >> QCD : new scale m c,b const., m u,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 Q2Q2 time
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 40/62 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, p T =0, x 1 =x 2 2 x m charm 3 GeV RHIC ( s=0.2TeV): x = 0.015 LHC ( s=14TeV): x = 2x10 -4
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 41/62 Heavy Quark Production (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). Heavy-quark production at LHC, compared to RHIC expect factors Charm 10 Beauty 100
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 42/62 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 of vanishing 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.
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 43/62 How to measure Heavy- Quark Production e.g., D 0, c = 123 m displaced decay vertex is signature of heavy-quark decay need precise pointing to collision vertex
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 44/62 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).
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 45/62 Where does all the charm go? D0D0 DD DsDs cc J Total charm cross section: open charm hadrons, e.g. D 0, D *, c, … or c,b e( ) + X Hidden-charm mesons, e.g. J/ carry ~ 1 % of total charm Statistics plot: H. Yang and Y. Wang, U Heidelberg.
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 46/62 Plot: A. Shabetai D 0 + + K - Reconstruction D 0, c = 123 m ++ K-K-
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 47/62 Measure secondary decay vertex Direct reconstruction of D 0 address heavy-quark production with 1 st year of data taking Many other channels, e.g. D +, D* Also: single-electrons from heavy-flavor decays Open Charm Performance ALICE: PPR.vol.II, J. Phys. G 32 (2006) 1295. Simulation: 10 9 p+p, 10 8 p+Pb, 10 7 Pb+Pb collisions
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 48/62 D* meson Identification D* ± analysis: Yifei Wang, Ph.D. thesis, University of Heidelberg, in preparation. D* + D 0 + + Identify D* + through M[D* + - D 0 ] Subtract resonance decay to D 0 Two different methods to address total charm production
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 49/62 Viele neue interessante Signale in ALICE bei LHC: z.B. Hadronen mit schweren Quarks (charm und beauty) D 0, D +, D *, D s, J/ ’, c b
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda Quarkonia
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 51/62 Charmonium Bound state of charm- and anti-charm quark Hidden-charm meson m J/ = 3.1 GeV, r J/ = 0.45 fm, m J/ ' = 3.6 GeV, J P = 1 - states Minimum formation time = r J/ / c = 0.45 fm Charm-quark production at time scale t c ~ 1/2m c 0.08 fm Separation between initial production and hadronization (factorization)
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 52/62 Debye Screening
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 53/62 Quarkonia as a Thermometer Check for melting of bottomonium (b-bbar) at T deconfined 2 T c Check for melting of charmonium (c-cbar) at T deconfined 1.2 T c Absolute numbers model-dependent T fo :
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 54/62 J/ Production suppression, compared to scaled p+p regeneration, enhancement Low energy (SPS):few ccbar quarks in the system suppression of J/ High energy (LHC): many ccbar pairs in the system enhancement of J/ Signal of de-confinement + thermalization of light quarks ! (SPS) P. Braun-Munzinger and J. Stachel, Nature 448 (2007) 302.
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 55/62 Statistical Hadronization of Charm large charm production at LHC strong generation of J/ striking centrality dependence Signature for QGP formation ! Initial conditions at LHC ? Need to measure total charm production in PbPb ! Assumes kinetic equilbration of charm ! cc A. Andronic, P. Braun-Munzinger, K. Redlich, J. Stachel, Phys. Lett. B 652 (2007) 259.
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 56/62 Charmonium production In central Pb+Pb collisions at top SPS energy: J/ ’ to J/ ratio approaches thermal limit Indicates kinetic equilibration of charm
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 57/62 Examples of the ALICE physics potential - Open charm: D 0 K - + + (already shown) - Quarkonia: J/ , - Global event properties Will be addressed in first year of pp collisions
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 58/62 First Physics with ALICE Results from simulations 1 day of data taking Address: - multiplicity - mean transverse momentum - hadro-chemistry
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 59/62 Charmonia via Di-Electron Measurement electron ID with TPC and TRD expect 2500 mesons per Pb+Pb year with good mass resolution and S/B Simulation: 2·10 8 central PbPb collisions J/ c1 c2 Simulation: pp coll.
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 60/62 Heavy Flavor in Muon Channel muon channel: J/ , + - (2.5 < < 4) 60000 J/ and 2000 initial sample sufficient to study production rates of J/ and states in muon channel J/ b b
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 61/62 LHC: Schedule Nov 2009: 1 st pp collisions very short run at 900 GeV Long run of pp collisions at 7- 10 TeV end of 2010:3 - 4 weeks Pb+Pb collisions at 2.8 - 3.9 TeV *short technical stop over Christmas period
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XXIII Graduate Days, Heidelberg, 5 9 Oct, 2009 Kai Schweda 62/62 ALICE Ready for Physics !
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