LHC, 11 Jul 2008 Kai Schweda Hadron Yield Ratios Fig.3.3 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/
LHC, 11 Jul 2008 Kai Schweda 2 Chemical Freeze-Out vs Energy Fig.3.4 A. Andronic et al., NPA 772 (2006) 167. With increasing energy: T ch increases and saturates at T ch = 160 MeV Coincides with Hagedorn temperature Coincides with early lattice results limiting temperature for hadrons, T ch 160 MeV ! B decreases, B = 1MeV at LHC Nearly net-baryon free !
LHC, 11 Jul 2008 Kai Schweda 3 Phase Diagram Fig.3.5
LHC, 11 Jul 2008 Kai Schweda 4 Debye Screening Fig.3.6
LHC, 11 Jul 2008 Kai Schweda 5 J/ Production Fig.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.
LHC, 11 Jul 2008 Kai Schweda 6 J/ Enhancement at LHC Fig.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/ cc
LHC, 11 Jul 2008 Kai Schweda 7 Sonnenspektrum Graphik: Max-Plack-Institut für Plasmaphysik Wellenlänge und Intensität festgelegt durch Temperatur T Sonne = 5500 C (an der Oberfläche)
LHC, 11 Jul 2008 Kai Schweda 8 Wie heiss ist die Quelle ? N K+K+ K0K0 K-K- N E = mc 2 (GeV) Teilchenhäufigkeit Lichtquelle Teilchenquelle Häufigkeit von Teilchen am besten beschrieben durch T = C = 2 Trillionen C mal heisser als im Innern der Sonne !