Presentation is loading. Please wait.

Presentation is loading. Please wait.

Heavy Ion Collisions at the LHC startup: p+p 2007 Pb+Pb 2007/8 Urs Achim Wiedemann Physics Department, CERN 9 October 2004 ALICE-Korea Workshop.

Published byJanice Stewart Modified over 8 years ago

Similar presentations

Presentation on theme: "Heavy Ion Collisions at the LHC startup: p+p 2007 Pb+Pb 2007/8 Urs Achim Wiedemann Physics Department, CERN 9 October 2004 ALICE-Korea Workshop."— Presentation transcript:

1 Heavy Ion Collisions at the LHC startup: p+p 2007 Pb+Pb 2007/8 Urs Achim Wiedemann Physics Department, CERN 9 October 2004 ALICE-Korea Workshop

2 Kinematics at the LHC small-x: determines properties of the medium large Q : determines probes of the medium 2

3 Hadronization versus Thermalization of Partons h h h in vacuum in QGP 1Ge V 10 GeV 100 GeV 100 fm 1 fm Dynamics of hadronization Jet absorption Jet heating Dynamics of the bulk Partonic equilibration processes

4 Setting the Transverse Momentum Scales ● High parton thermalization jet tomography ● Intermediate dynamics of hadronization ● Soft bulk dynamics

5 High pt Partons as Probes of Dense Matter 1. hadronic high-pt spectra

6 Centrality Dependence: Au+Au vs. d+Au Preliminary DataFinal Data ● Final state suppression ● Initial state enhancement

7 The medium-modified Final State Parton Shower Medium characterized by transport coefficient: Baier, Dokshitzer, Mueller, Peigne, Schiff (1996); Zakharov (1997); Wiedemann (2000); Gyulassy, Levai, Vitev (2000); Wang... Salgado,Wiedemann PRD68:014008 (2003) ● energy loss of leading parton ● pt-broadening of shower

8 Quenching of Leading Hadroproduction suppression of leading hadrons governed by X.N. Wang, nucl-th/0307036 Centrality dependence tests interplay of density and geometry E.Wang, X.N. Wang, PRL 89 (2002) 162301; Gyulassy, Vitev, Wang PRL 89 (2002) 252301; Salgado, Wiedemann PRL 89 (2002) 092303 suppression implies scaling X.N. Wang, nucl-th/0307036

9 Eskola, Honkanen, Salgado, Wiedemann, 2004 Fragility of leading hadron spectra as hard probe ● surface emission limits sensitivity to density

10 Testing the Mechanism: E-Loss of Heavy Quarks ● medium-induced radiation fills the dead-cone massive massless dead cone Armesto, Salgado, Wiedemann, hep-ph/0312106 ● vacuum radiation suppressed in the dead-cone Dokshitzer, Kharzeev, PLB 519 (2001) 199 ● total energy loss comparable but smaller than in the massless case Armesto, Salgado, Wiedemann, hep-ph/0312106 Uncertainties: - massive quarks are slower - finite energy corrections large (hadronization inside medium relevant for higher pt) Djordjevic, Gyulassy, nucl-th/0310076 B.W. Zhang, E. Wang, X.N. Wang, nucl-th/0309040

11 Beyond Leading Hadroproduction Where does this associated radiation go to ? How does this parton thermalize ?

12 Jets in Heavy Ion Collisions at the LHC ● Experiments at LHC will detect jets above background ● How can we quantify their medium modifications above background ? What do we learn from them ? A. Accardi et al., hep-ph/0310274 CERN TH Yellow Report

13 'Jet Heating': Jet Shapes and Jet Multiplicities Salgado, Wiedemann, hep-ph/0310079, Phys. Rev. Lett. in press ● Energy fraction in fixed jet cone weakly dependent on medium medium vacuum ● Multiplicity within small jet cone broadens significantly unaffected by high-multiplicity background !. kt

14 Armesto, Salgado, Wiedemann, 2004 Asymmetric Jet Shapes test Collective Flow ● Hard partons are not produced in the rest frame comoving with the medium test this

15 Theory predicts ● Characteristic L- dependence ● Dependence on the identity of the parent parton ● Relation between energy loss and pt-broadening ● Dependence on collective motion and energy density of medium Experimental Tests ➔ leading hadron spectra as function of centrality and orientation w.r.t. reaction plane ➔ jets and jet-like correlations ➔ charmed (beauty) hadrons ➔ - ratio at high pt ➔ hadroproduction associated to high-pt trigger particles ➔ jet shapes and jet multiplicity distributions

16 Intermediate pt Fragmentation inside the medium: what happens now ?

17 Breakdown of Independent (pert.) Fragmentation ● Jet quenching does not affect ratio in contrast to observation ● How does the bleaching of color charges proceed dynamically ? a bare colored parton dressed quark or color string or diquark or... 'bleached' hadron Recombination String Fragmentation Diquark Dressing S. Bass pQCD:

18 Fragmentation versus Recombination start from quark spectrum: ● Fragmentation: ● Recombination recombination fragmentation Exp. spectrum: recombination dominates Powerlaw tail: fragmentation dominates Range of applicability: intermediate pt upper bound on pt Castillo(STAR)@HIC03 ● Quark number scaling of v2 Voloshin, QM2002, nucl-ex/0210014

19 Soft pt Statistics and Dynamics of the Bulk

20 Hadronization in the Grand Canonical Ensemble Which microscopic dynamics turns quarks and gluons into hadrons ? ● Recent refinements: - system size dependence - hadronization of charm ● Hadronization of a QGP in chemical equilibrium at (T, ) ? de Forcrand, Philipsen 1, Fodor, Katz Allton et al. D'Elia, Lombardo ● Hadron yields and ratios fitted by statistical model in terms of (T, )

21 'Blastwave Model': Snapshot at Freeze-out ● Recent refinements: anisotropy What is the microscopic dynamics determining these distributions ? Lisa, Retiere, nucl-th/03122024 ● Low pt Hadron Spectra fitted by - local thermal equilibrium - collective flow space-time geometry: HBT ?, asHBT !

22 Hydro: Learning from Agreements or Deviations ? Hirano, Nara, nucl-th/0307015 Kolb, Rapp PRC67 (2003) 044903 Molnar, Gyulassy, NPA 697 (2002) 495 ● How to understand the range of validity of hydrodynamics ? Opacity Problem ! - hadronization may change flow by by a large factor (2-3) - realistic freeze-out condition (beyond Cooper-Frye) needed for some data, e.g. HBT ● Hydrodynamics + statistical hadronization works up to for - pt -spectra - rapidity distribution - elliptic flow Molnar, Voloshin PRL 91 (2003) 092301 Hadronization matters ! Sinyukov, Akkelin, Hama, PRL 89 (2002) 052301 Akkelin, Braun-Munzinger, Sinyukov, NPA710 (2002) 439 Tomasik, Wiedemann PRC68 (2003) 034905

23 Saturation Physics and its possible tests heavy ion collisions non-linear small-x evolution perturbatively calculable High density: but Balitsky; Kovchegov; Jalilian-Marian,Kovner, Leonidov, Weigert;...

24 The projectile: nuclear parton distribution at small x ● lepton-nucleus scattering at small x ● unintegrated target gluon distribution at initial rapidity ● Evolution with rapidity: Balitsky 1994, Kovchegov 1999 [ ] *

25 Geometric Scaling at small x ● Solution of BK-equation depends on saturation scale only ● Data on lepton-proton scattering show geometric scaling Stasto, Golec-Biernat, Kwiecinski, 1999 ● Data on lepton-nucleus scattering Armesto, Salgado, Wiedemann, 2004

26 The Day 1 Observable at RHIC and LHC signal proportional to multiplicity PHOBOS, Phys. Rev. Lett. 85 (2000) 3100 Au+Au at RHIC ● Multiplicity important as centrality measure and for estimates of energy density Bjorken, 1982

27 A model for the multiplicity in A+A Ansatz: Armesto, Salgado, Wiedemann, 2004 provides fair description of multiplicity and its centrality dependence at SPS and RHIC

28 Multiplicity: expectations from naïve extrapolations Armesto, Salgado, Wiedemann hep-ph/0407018 our model logarithmic extrapolation figures from G. Roland

29 ● What determines the initial energy density created in nucleus-nucleus collisions ? ● What is the nature of equilibration processes and what is their time scale ? ● What is the dynamics of hadronization and how does it depend on system size ? ●... The RHIC-ness of accessible Scales and Questions 1Ge V 10 GeV 100 GeV 100 fm 1 fm dynamics of hadronization Jet absorption Onset of thermalization “DIS on QGP” dynamics of the bulk + A-dependence + - dependence + d-Au collisions + LHC

Download ppt "Heavy Ion Collisions at the LHC startup: p+p 2007 Pb+Pb 2007/8 Urs Achim Wiedemann Physics Department, CERN 9 October 2004 ALICE-Korea Workshop."

Similar presentations

What do we Learn From Azimuthal Correlation Measurements in PHENIX Roy. A. Lacey Nuclear Chemistry, SUNY, Stony Brook.

What do we Learn From Azimuthal Correlation Measurements in PHENIX Roy. A. Lacey Nuclear Chemistry, SUNY, Stony Brook.
Elliptic flow of thermal photons in Au+Au collisions at 200GeV QNP2009 Beijing, Sep 21 - 26, 2009 F.M. Liu Central China Normal University, China T. Hirano.

Elliptic flow of thermal photons in Au+Au collisions at 200GeV QNP2009 Beijing, Sep , 2009 F.M. Liu Central China Normal University, China T. Hirano.
1 Jet Structure of Baryons and Mesons in Nuclear Collisions l Why jets in nuclear collisions? l Initial state l What happens in the nuclear medium? l.

1 Jet Structure of Baryons and Mesons in Nuclear Collisions l Why jets in nuclear collisions? l Initial state l What happens in the nuclear medium? l.
TJH: ISMD 2005, 8/9-15 Kromeriz, Czech Republic TJH: 1 Experimental Results at RHIC T. Hallman Brookhaven National Laboratory ISMD Kromeriz, Czech Republic.

TJH: ISMD 2005, 8/9-15 Kromeriz, Czech Republic TJH: 1 Experimental Results at RHIC T. Hallman Brookhaven National Laboratory ISMD Kromeriz, Czech Republic.
1 Dihadron Tomography of High Energy AA Collisions in NLO pQCD Hanzhong Zhang Department of Physics, Shandong University Institute of Particle Physics,

1 Dihadron Tomography of High Energy AA Collisions in NLO pQCD Hanzhong Zhang Department of Physics, Shandong University Institute of Particle Physics,
Future Prospects in QCD BNL, July 17-22, 2006 1 Jets and Heavy Flavors Jet and Heavy Flavor Probes of Hot QCD Matter Peter Jacobs, LBNL.

Future Prospects in QCD BNL, July 17-22, Jets and Heavy Flavors Jet and Heavy Flavor Probes of Hot QCD Matter Peter Jacobs, LBNL.
Jet Quenching in Heavy Ion Collisions at RHIC and LHC Urs Achim Wiedemann CERN PH-TH Erice, 2008.

Jet Quenching in Heavy Ion Collisions at RHIC and LHC Urs Achim Wiedemann CERN PH-TH Erice, 2008.
Charm & bottom RHIC Shingo Sakai Univ. of California, Los Angeles 1.

Charm & bottom RHIC Shingo Sakai Univ. of California, Los Angeles 1.
Jet Discovery of Jet Quenching and Beyond Xin-Nian Wang LBNL, June 29, 05.

Jet Discovery of Jet Quenching and Beyond Xin-Nian Wang LBNL, June 29, 05.
Heavy Quark Probes of QCD Matter at RHIC Huan Zhong Huang University of California at Los Angeles ICHEP-2004 Beijing, 2004.

Heavy Quark Probes of QCD Matter at RHIC Huan Zhong Huang University of California at Los Angeles ICHEP-2004 Beijing, 2004.
Relativistic Heavy-Ion Collisions: Recent Results from RHIC David Hardtke LBNL.

Relativistic Heavy-Ion Collisions: Recent Results from RHIC David Hardtke LBNL.
High-p T spectra and correlations from Cu+Cu and Au+Au collisions in STAR Marco van Leeuwen, LBNL for the STAR collaboration.

High-p T spectra and correlations from Cu+Cu and Au+Au collisions in STAR Marco van Leeuwen, LBNL for the STAR collaboration.
Dunlop, WW 2006 1 What More Can Be Learned from High Pt Probes at RHIC? James Dunlop Brookhaven National Laboratory.

Dunlop, WW What More Can Be Learned from High Pt Probes at RHIC? James Dunlop Brookhaven National Laboratory.
Luan Cheng (Institute of Particle Physics, Huazhong Normal University) I. Introduction II. Interaction Potential with Flow III. Flow Effects on Light Quark.

Luan Cheng (Institute of Particle Physics, Huazhong Normal University) I. Introduction II. Interaction Potential with Flow III. Flow Effects on Light Quark.
XXXIII International Symposium on Multiparticle Dynamics, September 7, 2003 Kraków, Poland Manuel Calderón de la Barca Sánchez STAR Collaboration Review.

XXXIII International Symposium on Multiparticle Dynamics, September 7, 2003 Kraków, Poland Manuel Calderón de la Barca Sánchez STAR Collaboration Review.
SQM2006, 03/27/2006Haibin Zhang1 Heavy Flavor Measurements at STAR Haibin Zhang Brookhaven National Laboratory for the STAR Collaboration.

SQM2006, 03/27/2006Haibin Zhang1 Heavy Flavor Measurements at STAR Haibin Zhang Brookhaven National Laboratory for the STAR Collaboration.
High p T  0 Production in p+p, Au+Au, and d+Au Stefan Bathe UC Riverside for the Collaboration Topics in Heavy Ion Collisions McGill University, Montreal,

High p T  0 Production in p+p, Au+Au, and d+Au Stefan Bathe UC Riverside for the Collaboration Topics in Heavy Ion Collisions McGill University, Montreal,
A NLO Analysis on Fragility of Dihadron Tomography in High Energy AA Collisions I.Introduction II.Numerical analysis on single hadron and dihadron production.

A NLO Analysis on Fragility of Dihadron Tomography in High Energy AA Collisions I.Introduction II.Numerical analysis on single hadron and dihadron production.
Identified Particle Ratios at large p T in Au+Au collisions at  s NN = 200 GeV Matthew A. C. Lamont for the STAR Collaboration - Talk Outline - Physics.

Identified Particle Ratios at large p T in Au+Au collisions at  s NN = 200 GeV Matthew A. C. Lamont for the STAR Collaboration - Talk Outline - Physics.
Heavy-to-light ratios as a test of medium-induced energy loss at RHIC and the LHC N. Armesto Quark Matter 2005: 18th International Conference on Ultra-Relativistic.

Heavy-to-light ratios as a test of medium-induced energy loss at RHIC and the LHC N. Armesto Quark Matter 2005: 18th International Conference on Ultra-Relativistic.

Similar presentations

Ads by Google