physics @ lhc, 11 jul 2008 kai schweda hadron yield ratios fig.3.3 1) at rhic: t ch = 160 ± 10 mev...
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Physics @ LHC, 11 Jul 2008 Kai Schweda
Hadron Yield RatiosFig.3.3
1) At RHIC:
Tch = 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.
2 Physics @ LHC, 11 Jul 2008 Kai Schweda
Chemical Freeze-Out vs EnergyFig.3.4
A. Andronic et al., NPA 772 (2006) 167.
With increasing energy:
• Tch increases and saturates
at Tch = 160 MeV
• Coincides with Hagedorn
temperature
• Coincides with early lattice results
limiting temperature for
hadrons, Tch 160 MeV !
B decreases, B = 1MeV at LHC
Nearly net-baryon free !
3 Physics @ LHC, 11 Jul 2008 Kai Schweda
Phase DiagramFig.3.5
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
4 Physics @ LHC, 11 Jul 2008 Kai Schweda
Debye ScreeningFig.3.6
5 Physics @ LHC, 11 Jul 2008 Kai Schweda
J/ ProductionFig.3.7
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.
6 Physics @ LHC, 11 Jul 2008 Kai Schweda
J/ Enhancement at LHCFig.3.8
large ccbar production at
LHC
corona effects negligible
regeneration of J/
dominates
striking centrality
dependence
Signature for QGP
formation !
Initial conditions at LHC ?
A. Andonic et al., nucl-th/0701079.
cc
7 Physics @ LHC, 11 Jul 2008 Kai Schweda
Sonnenspektrum
Graphik: Max-Plack-Institut für Plasmaphysik
Wellenlänge und Intensität festgelegt durch Temperatur TSonne = 5500 C(an der Oberfläche)
8 Physics @ LHC, 11 Jul 2008 Kai Schweda
Wie heiss ist die Quelle ?
N
K+
K0
K-
N
E = mc2 (GeV)
Te
ilch
enh
äu
figke
it
0.4 0.80 1.61.2
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 !