EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 1/26 (Some) Bulk Properties at RHIC Kai Schweda, University of Heidelberg / GSI Darmstadt Many thanks to organizers !
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 2/26 Outline Introduction Collectivity at RHIC - transverse radial flow - tranverse elliptic flow - extracting /s Heavy quark dynamics Summary
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda Operated modes: Au 9, 20, 64, 130, 200 GeV/2n Cu + 22, 62, 200 GeV/2n d GeV/2n p + 22, 62, 200, 500 GeV Planned or possible modes: Au 5 GeV/2n p GeV/2n
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 4/26 Hadron spectra from RHIC p+p and Au+Au collisions at 200 GeV White papers - STAR: Nucl. Phys. A757, p102. Full kinematic reconstruction of (multi-) strange hadrons in large acceptance of STAR
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda HI - Collision History Plot: R. Stock, arXiv: [nucl-ex]. T c(ritical) : quarks and gluon hadrons T ch(emical) : hadron abundancies freeze out T fo : particle spectra freeze out
EMMI workshop, St. Goar, 31 Aug 3 Sep, 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 , Nucl. Phys. A757, STAR: p102; PHENIX: p184; Statistical Model calculations: P. Braun-Munzinger et al. nucl-th/
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 7/26 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
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 8/26 (anti-)Protons From RHIC (anti-)Protons From RHIC 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, (R).
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 9/26 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, ( ), *A. Baran, W. Broniowski and W. Florkowski, Acta. Phys. Polon. B 35 (2004) 779. STAR Preliminary
Anisotropy Parameter v 2 y x pypy pxpx coordinate-space-anisotropy momentum-space-anisotropy Initial/final conditions, EoS, degrees of freedom
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 11/26 v 2 in the Low-p T Region P. Huovinen, private communications, v 2 approx. linear in p T, mass ordering from light to heavier àcharacteristic of hydrodynamic flow ! à sensitive to equation of state
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 12/26 v 2 of and multi-strange Strange-quark flow - partonic collectivity at RHIC ! QM05 conference: M. Oldenburg; nucl-ex/
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 13/26 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: [nucl-ex].
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 14/26 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, (2003); STAR, Phys. Rev. C66, (2002); Hydro-calcs.: P. Kolb, J. Sollfrank, and U. Heinz, Phys. Rev.C62, (2000). Glauber initial conditions
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 15/26 Non-ideal Hydro-dynamics M.Luzum and R. Romatschke, PRC (2008); P. Romatschke, arXiv: finite shear viscosity reduces elliptic flow many caveats, e.g.: - initial eccentricity (Glauber, CGC, …) - equation of state - hadronic contribution to /s cf. talks by D. Fernandez-Fraile and D. Rischke
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 16/26 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 = MeV (~ T ch ), T = 0.4 (c) 3) Multi-strange v 2 : and multi-strange hadrons and do flow! 4) Model - dependent /s: (0?), x 1/4 Deconfinement & Partonic (u,d,s) Collectivity !
EMMI workshop, St. Goar, 31 Aug 3 Sep, 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
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 18/26 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 + 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:
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 19/26 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.
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 20/26 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
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 21/26 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 R, F Plot: J. Dunlop (STAR), QM2009, Open Heavy-flavor in heavy-ion collisions, Calcs: R. Vogt,Eur. Phys. J. C, s x (2008), M. Cacciari, 417th Heraeus Seminar, Bad Honnef (2008).
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 22/26 STAR MicroVertex Tracker Active pixel sensors (APS) Two layers of thin silicon - Full open charm measurements - Full resonance measurements with both hadron and lepton decays STAR and PHENIX Si - Upgrades PHENIX Silcon Vertex Tracker 2 layers of pixel sensors (ALICE-type) 2 layers of thin silicon strip - Full open charm measurements High-statistics Au+Au 200GeV: 2012* *T. Roser, RHIC Retreat, Mystic, CT, July 2009.
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 23/26 ALICE at LHC TPC TRD 1000 scientists, 30 nations ITS: measures secondary vertex, open heavy-flavor, c and b TPC: tracks and identifies charged particles, (e, ), , K, p TRD: identifies electrons above 1 GeV, fast trigger (6 s) ITS
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 24/26 resolution at 10 GeV: measured 6.5% design 4.5% TPC commissioning performance at design, TPC ready for collisions transverse momentum resolution, B=0.5 Tparticle identification via dE/dx resolution: measured <5% design 5.5% –TPC installed in ALICE, running continuously May-October 2008, and since Aug 2009 –60 million events (cosmics, krypton, and laser) recorded
ITS: installed & commissioned SSD: charge correlation p-side vers. n-side Drift speed constant for hours SDD: Drift speed calibration & monitoring versus time after alignment before alignment SPD: Point resolution (σ spatial ) σ Δx = √2 x σ spatial Data: 14 μm Simulation: 11 μm
EMMI workshop, St. Goar, 31 Aug 3 Sep, 2009 Kai Schweda 26/26 Summary Strong collective expansion at RHIC = 0.6 c, = 0.07 Small /s < 10 x 1/4 Large uncertainty (exp. and theory) in at RHIC need Si - upgrades Measure spectra, correlations and v 2 of: e ±, D 0, D +, D *, D s, J/ c, b, to identify and characterize QGP ! LHC ready for Physics !