Particle Ratios and the QCD Critical Temperature

Abstract

We show how the measured particle ratios at RHIC can be used to provide non-trivial information about the critical temperature of the QCD phase transition. This is obtained by including the effects of highly massive Hagedorn resonances on statistical models, which are used to describe hadronic yields. Hagedorn states are relevant close to $T_c$ and have been shown to decrease $\eta /s$ to the KSS limit and allow for quick chemical equilibrium times in dynamical calculations of hadrons. The inclusion of Hagedorn states creates a dependence of the thermal fits on the Hagedorn temperature, $T_H$, which is assumed to be equal to $T_c$, and leads to an overall improvement of thermal fits. We find that for Au+Au collisions at RHIC at $\sqrt{s_{NN}}=200$ GeV the best square fit measure, ${\chi }^2$, occurs at $T_c\sim 176$ MeV and produces a chemical freeze-out temperature of 170.4 MeV and a baryon chemical potential of 27.8 MeV.

6 pages, 2 figures, talk presented at the International Conference on Strangeness in Quark Matter, Buzios, Rio de Janeiro, Brazil, Sept. 27 - oct. 2, 2009

References in corpus (10)

• Viscosity in Strongly Interacting Quantum Field Theories from Black Hole Physics
• The QCD Equation of State with almost Physical Quark Masses
• Equation of state and QCD transition at finite temperature
• Therminator: Thermal heavy-Ion generator
• Chemical freeze-out in ultra-relativistic heavy ion collisions at sqrt(s)_NN = 130 and 200 GeV
• Fast Equilibration of Hadrons in an Expanding Fireball
• High-Precision Thermodynamics and Hagedorn Density of States
• Dynamics of Chemical Equilibrium of Hadronic Matter Close to $T_c$
• Chemical equilibration due to heavy Hagedorn states
• Particle Ratios as a Probe of the QCD Critical Temperature

Cited by in corpus (7)

• THERMINATOR 2: THERMal heavy IoN generATOR 2
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• Dilepton production in p+p, Cu+Cu and Au+Au collisions at 200 AGeV
• Dark Sector Glueballs at the LHC
• Cosmological QCD phase transition in steady non-equilibrium dissipative Hořava-Lifshitz early universe
• Hagedorn States and Thermalization
• Hagedorn States and Thermalization in Heavy Ion Collisions