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 !