Darmstadt 2008 – wissenschaftliches Programm
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HK: Fachverband Physik der Hadronen und Kerne
HK 49: Theorie
HK 49.8: Vortrag
Freitag, 14. März 2008, 15:45–16:00, 2F
Effects of mesonic correlations in the QCD phase transition — •Michael Buballa1, David Blaschke2,3, Andrey E. Radzhabov3, and Mikhail K. Volkov3 — 1TU Darmstadt, Germany — 2University of Wroclaw, Poland — 3JINR Dubna, Russia
We study the finite temperature phase transition of strongly interacting matter within a nonlocal chiral quark model of the NJL type coupled to a Polyakov loop. In contrast to previous investigations which were restricted to the mean-field approximation, mesonic correlations are included by evaluating the quark-antiquark ring sum. For physical parameters, we find that the pions dominate the pressure below the phase transition. In this regime, the pressure is quite insensitive to the details of the interaction and agrees almost exactly with that of an ideal pion gas. At temperatures above Tc the mesonic contributions die out and the pressure is well described by the mean-field result. Finally, we compare our results with the resonance gas model and with lattice simulations. If we take unphysically large quark masses, as used on the lattice, the meson effects are suppressed.