1. Kollektive Eigenschaften in Kern-Kern Kollisionen bei hohen Energien
Kai Schweda, Physikalisches Institut/ GSI Darmstadt

2. Quantum Chromodynamics
Quantum Chromodynamics (QCD) is the established theory of strongly interacting matter.
Gluons hold quarks together to from hadrons:
Gluons and quarks, or partons, typically exist in a color singlet state: confinement.
meson
baryon

3. Natur Experiment COBE: Discovery `baby photo’ of the universe
LHC RHIC COBE
10 –6 sec –4 sec min Mil Jahre
Quark-Gluon
Plasma
Nukleonen
Kerne
Atome
Heute
Natur
Experiment
Urknall
John Mather
George Smoot
COBE: Discovery `baby photo’ of
the universe
RHIC: Live history of the universe

4. Quark Gluon Plasma Quark Gluon Plasma: Deconfined and
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. Au + Au Collisions at RHIC
Peripheral Event
STAR
(real-time Level 3)

6. Au + Au Collisions at RHIC
Mid-Central Event
STAR
(real-time Level 3)

7. Au + Au Collisions at RHIC
Central Event
STAR
(real-time Level 3)

8. Pressure, Flow, … Thermodynamic identity – entropy p – pressure
U – energy V – volume
t = kBT, 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

9. Protons From RHIC
More central collisions
In central collisions, spectrum becomes more concave  collective flow !
Flow velocity <b> = 0.60 ± 0.05 in most central collisions

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

11. v2 at Low Momentum - Mass hierarchy  collective flow !
P. Huovinen, private communications, 2004
- Mass hierarchy  collective flow !
- Hydro-dynamical model : acces to equation of state !

12.  -meson Flow: Partonic Flow
-mesons:
little hadronic interactions
strong collective flow
formed via coalescence of
thermal s-quarks
 Collectivity at quark level !
STAR Preliminary: SQM06, S. Blyth
Hwa and Yang, nucl-th/ ; Chen et al., PRC73 (2006)

13. Collectivity, Deconfinement at RHIC
- v2 of light hadrons and
multi-strange hadrons
- scaling by the number of
quarks
At RHIC:
 number-of-constituent quark scaling
 De-confinement
PHENIX: PRL91, (03)
STAR: PRL92, (04), 95, (05)
nucl-ex/ , QM05
S. Voloshin, NPA715, 379(03)
Models: Greco et al, PRC68, (03)
Chen, Ko, nucl-th/
Nonaka et al. PLB583, 73(04)
X. Dong, et al., Phys. Lett. B597, 328(04).
i ii

14. In central Au+Au collisions at RHIC
EoS Parameters at RHIC
In central Au+Au collisions at RHIC
- partonic freeze-out:
*Tpfo = 165 ± 10 MeV weak centrality dependence
vpfo ≥ 0.2 (c)
- hadronic freeze-out:
*Tfo = 100 ± 5 (MeV) strong centrality dependence
vfo = 0.6 ± 0.05 (c)
Systematic studies are needed to understand the
centrality dependence of the EoS parameters
* Thermalization assumed

15. Quark Masses Strong interactions do not affect heavy-quark masses.
Higgs mass: electro-weak symmetry breaking. (current quark mass)
QCD mass: Chiral symmetry breaking. (constituent quark mass)
Strong interactions do not affect heavy-quark masses.
Important tool for studying properties of the hot/dense medium at RHIC.
Test pQCD predictions at RHIC and LHC.
Total quark mass (MeV)

16. J/y Enhancement at LHC Statistical hadronization J/y: c c  scc
 strong centrality dependence of J\y yield at LHC
Need total charm yields !
Measure D0, D±, Lc
Probe deconfinement and thermalization
J/y: c c
 scc
Number of participants
More central collisions
Calculations: P. Braun Munzinger, K. Redlich, and J. Stachel, nucl-th/

17. Multiply Heavy-flavored Hadrons
Statistical hadronization - de-confined heavy-quarks
equilibrated heavy-quarks
 Enhancement up to x1000 !
Measure Xcc, Wcc, Bc, (Wccc)
Need total charm yields
Probe deconfinement and LHC
Quark Gluon Plasma !
Quarks and gluons  hadrons
Pb+Pb
Wccc / D :
p+p c
c c
x1000
F. Becattini, Phys. Rev. Lett. 95, (2005);
P. Braun Munzinger, K. Redlich, and J. Stachel, nucl-th/

18. Heavy-Flavor Collectivity
The key point is to idenitfy and measure
Heavy-Flavor Collectivity
D0, D, D+s, L+C, J/y, B0, B±, , …

19. Large Hadron Collider LHC am CERN Energie in einer Blei-Blei Kollision
1150 TeV = 0.18 mJ
Faktor 300 höher als in SPS Experimenten
sehr heisser Feuerball!
T = 1000 MeV

20. ALICE beim LHC Bis zu 60000 geladene Teilchen
TRD
TPC
ITS
Bis zu geladene Teilchen
Faktor 25 höher als beim SPS
~ PetaByte (1015) pro Jahr

22. J/y  e+ + e- Reconstruction
J/y: c c
: b b
J/y  e+ + e- (BR = 6%)
Reconstruct invariant mass
TRD identifies electrons
 Identify quarkonia

23. 1) LHC heavy-flavor program: 2) FAIR / CBM program:
Taken from P. Senger
1) LHC heavy-flavor program:
2) FAIR / CBM program:
- Study medium properties
- pQCD in hot and dense medium
- Search for phase boundary.
- Chiral symmetry restoration
Start: 2007
Start: ~2012