Particle ratios and the QCD critical temperature

J Noronha-Hostler (1) , Jorge Noronha (2) , Carsten Greiner (1)

1 ITP - Institut für Theoretische Physik [Frankfurt am Main]
2 Department of Physics

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 η/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 √ s N N = 200 GeV the best square fit measure, χ 2, occurs at T c ∼ 176 MeV and produces a chemical freeze-out temperature of 170.4 MeV and a baryon chemical potential of 27.8 MeV.

Mots clés: Physical Sciences

J Noronha-Hostler, Jorge Noronha, Carsten Greiner. Particle ratios and the QCD critical temperature. Journal of Physics G: Nuclear and Particle Physics, 2010, 37 (9), pp.94062. ⟨10.1088/0954-3899/37/9/094062⟩. ⟨hal-00600862⟩