(Some) Bulk Properties at RHIC (Some) Bulk Properties at RHIC Many - PowerPoint PPT Presentation

(Some) Bulk Properties at RHIC (Some) Bulk Properties at RHIC Many thanks to organizers ! Kai Schweda, University of Heidelberg / GSI Darmstadt EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 1/26

Outline  Introduction  Collectivity at RHIC - transverse radial flow - tranverse elliptic flow - extracting η /s  Heavy − quark dynamics  Summary EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 2/26

Operated modes: Au +Au @ 9, 20, 64, 130, 200 GeV/2n Cu + Cu @ 22, 62, 200 GeV/2n d + Au @ 200 GeV/2n p + p @ 22, 62, 200, 500 GeV Planned or possible modes: Au +Au @ 5 GeV/2n p + Au @ 200 GeV/2n EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda

Hadron spectra from RHIC p+p and Au+Au collisions at 200 GeV Full kinematic reconstruction of (multi-) strange hadrons in large acceptance of STAR White papers - STAR: Nucl. Phys. A757, p102. EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 4/26

HI - Collision History  T c(ritical) : quarks and gluon ⇒ hadrons  T ch(emical) : hadron abundancies freeze out  T fo : particle spectra freeze out Plot: R. Stock, arXiv:0807.1610 [nucl-ex]. EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda

Hadron Yield − Ratios 1) At RHIC: T ch = 160 ± 10 MeV µ B = 25 ± 5 MeV 2) γ 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. EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda

Pressure, Flow, … Pressure, Flow, … Pressure, Flow, Pressure, Flow, Thermodynamic identity d dU pdV σ – entropy p – pressure � � = + U – energy V – volume τ = 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 EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 7/26

(anti-)Protons From RHIC (anti-)Protons From RHIC (anti-)Protons From RHIC (anti-)Protons From RHIC Au+Au@130GeV Au+Au@130GeV Au+Au@130GeV Au+Au@130GeV More central collisions 2 2 m p mass = + T T Centrality dependence: - spectra at low momentum de-populated, become flatter at larger momentum ➠ stronger collective flow in more central tronger collective flow in more central coll oll.! .! STAR: Phys. Rev. C70, 041901(R). EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 8/26

Kinetic Freeze-out at RHIC 1) Multi-strange hadrons 1) Multi-strange hadrons φ φ and Ω freeze-out earlier freeze-out earlier and Ω than than ( ( π π , , K K , , p p ) )   Collectivity prior to Collectivity prior to hadronization hadronization 2) Sudden single freeze-out*: 2) Sudden single freeze-out*: Resonance decays lower T Resonance decays lower T fo fo for ( for ( π π , , K K , , p p ) ) STAR Preliminary  Collectivity prior to Collectivity prior to  hadronization hadronization   Partonic Partonic Collectivity ? ? Collectivity STAR Data: Nucl. Phys. A757, (2005 102), *A. Baran, W. Broniowski and W. Florkowski, Acta. Phys. Polon. B 35 (2004) 779 . EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 9/26

Anisotropy Parameter v 2 coordinate-space-anisotropy ⇔ momentum-space-anisotropy y p y p x x � = � y 2 � x 2 � v 2 = cos2 � , � = tan � 1 ( p y ) � y 2 + x 2 � p x Initial/final conditions, EoS, degrees of freedom

v 2 in the Low-p T Region P. Hu ovinen, private communications, 2004 - v 2 approx. linear in p T , mass ordering from light π to heavier Λ ➠ characteristic of hydrodynamic flow ! ➠ sensitive to equation of state EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 11/26

v 2 of φ and multi-strange Ω  Strange-quark flow - partonic collectivity at RHIC ! QM05 conference: M. Oldenburg; nucl-ex/0510026. EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 12/26

Collectivity − Energy Dependence  Collectivity parameters < β T > and <v 2 > increase with collision energy strong collective  expansion at RHIC ! < β T > RHIC ≈ 0.6 expect strong partonic  expansion at LHC , < β T > LHC ≈ 0.8, T fo ≈ T ch K.S., ISMD07, arXiv:0801.1436 [nucl-ex]. EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 13/26

Elliptic Flow vs Collision Energy Glauber initial conditions  Centrality dependence: - initial eccentricity ε - 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). EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 14/26

Non-ideal Hydro-dynamics � s < 6/4 �  finite shear viscosity η reduces elliptic flow cf. talks by D. Fernandez-Fraile  many caveats, e.g.: and D. Rischke - initial eccentricity ε (Glauber, CGC, …) - equation of state - hadronic contribution to η /s M.Luzum and R. Romatschke, PRC 78 034915 (2008); P. Romatschke, arXiv:0902.3663. EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 15/26

Partonic Collectivity at RHIC 1) Copiously produced hadrons freeze-out π ,K,p: T fo = 100 MeV, β T = 0.6 (c) > β T (SPS) 2) Multi-strange hadrons freeze-out: T fo = 160-170 MeV (~ T ch ), β T = 0.4 (c) 3) Multi-strange v 2 : φ and multi-strange hadrons Ξ and Ω do flow! 4) Model - dependent η /s: (0?),1 - 10 x 1/4 π Deconfinement & Deconfinement & Partonic (u,d,s) ) Collectivity ollectivity ! Partonic EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 16/26

Heavy − flavor: a unique probe m c,b >> Λ QCD : new scale m c,b ≈ const., m u,d,s ≠ const. Q 2 • initial conditions: σ , σ cc bb test pQCD, µ R , µ F probe gluon distribution • early partonic stage: diffusion ( γ ), drag ( α ), flow probe thermalization X. Zhu, M. Bleicher, S.L. Huang, K.S., H. Stöcker, N. Xu, and P. Zhuang, PLB 647 (2007) 366. • hadronization: chiral symmetry restoration confinement statistical coalescence J/ ψ enhancement / suppression time EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda

Heavy − quark Correlations  c-cbar mesons are correlated PYTHIA: p + p @ 14 TeV • 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 ! 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. EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 18/26

Where does all the charm go? J / ψ Λ c D s D 0 D ±  Total charm cross section: open charm hadrons, e.g. D 0 , D * , Λ c , … or c,b → e( µ ) + X  Hidden-charm mesons, e.g. J/ ψ carry ~ 1 % of total charm Statistics plot: H. Yang and Y. Wang, U Heidelberg . EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 19/26

How to measure Heavy- Quark Production  e.g., D 0 , c τ = 123 µ m displaced decay vertex is signature of heavy-quark decay   need precise pointing to collision vertex EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 20/26

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 µ R , µ 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). EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 21/26

STAR and PHENIX Si - Upgrades STAR MicroVertex Tracker PHENIX Silcon Vertex Tracker Active pixel sensors (APS) 2 layers of pixel sensors (ALICE-type) Two layers of thin silicon 2 layers of thin silicon strip - Full open charm measurements - Full open charm measurements - Full resonance measurements with both hadron and lepton decays  High-statistics Au+Au collisions @ 200GeV: 2012* *T. Roser, RHIC Retreat, Mystic, CT, July 2009 . EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 22/26

ALICE at LHC 1000 scientists, 30 nations TRD ITS TPC ITS: measures secondary vertex, open heavy-flavor, c and b TPC: tracks and identifies charged particles, (e, µ ), π , K, p TRD: identifies electrons above 1 GeV, fast trigger (6 µ s) EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 23/26

TPC commissioning – TPC installed in ALICE, running continuously May-October 2008, and since Aug 2009 – 60 million events (cosmics, krypton, and laser) recorded transverse momentum resolution, B=0.5 T particle identification via dE/dx resolution: measured <5% design 5.5% resolution at 10 GeV: measured 6.5% design 4.5% • performance at design, TPC ready for collisions EMMI workshop, St. Goar, 31 Aug − 3 Sep, 2009 Kai Schweda 24/26