34 research outputs found
Hadronic correlations above the chiral/deconfinement transition
The statistical bootstrap model is critically revised in order to include a
medium-dependent resonance width in it. We show that a thermodynamic model with
a vanishing width below the Hagedorn temperature T_H and a Hagedorn
spectrum-like width above T_H may not only eliminate the divergence of the
thermodynamic functions above T_H, but also gives a satisfactory description
the lattice quantum chromodynamics (QCD) data on the energy density above the
chiral/deconfinement transition as the main result of this contribution. This
model allows to explain the absence of heavy resonance contributions in the fit
of the experimentally measured particle ratios at SPS and RHIC energies.Comment: 9 pages, 2 figures, contribution to proceedings of NAPP 2003,
Dubrovnik, Croatia, 26-31 May, 200
Transverse momentum spectra of J/psi and psi prime mesons from quark gluon plasma hadronization in nuclear collisions
Recent results on transverse mass spectra of J/psi and psi prime mesons in central Pb+Pb collisions at 158 AGeV are considered. It is shown that those results support a hypothesis of statistical production of charmonia at hadronization and suggest the early thermal freeze-out of J/psi and psi prime mesons. Based on this approach the collective transverse velocity of hadronizing quark gluon plasma is estimated to be \approx 0.2. Predictions for transverse mass spectra of hidden and open charm mesons at SPS and RHIC are discussed
Omega, J/psi and psi' production in nuclear collisions and quark gluon plasma hadronization
The transverse mass spectra of Omega, J/psi and psi' in Pb+Pb collisions at 158 AGeV are studied within a hydrodynamical model of the quark gluon plasma expansion and hadronization. The model reproduces the existing data with the common hadronization parameters: temperature T=T_H = 170 MeV and average collective transverse velocity v_T = 0.2
Omega, J/psi and psi' transverse mass spectra at RHIC
The transverse mass spectra of J/psi and psi' mesons and Omega hyperons produced in central Au+Au collisions at RHIC energies are discussed within a statistical model used successfully for the interpretation of the SPS results. The comparison of the presented model with the future RHIC data should serve as a further crucial test of the hypothesis of statistical production of charmonia at hadronization. Finally, in case of validity, the approach should allow to estimate the mean transverse flow velocity at the quark gluon plasma hadronization
Transverse activity of kaons and the deconfinement phase transition in nucleus-nucleus collisions
We found that the experimental results on transverse mass spectra of kaons produced in central Pb+Pb (Au+Au) interactions show an anomalous dependence on the collision energy. The inverse slopes of the spectra increase with energy in the low (AGS) and high (RHIC) energy domains, whereas they are constant in the intermediate (SPS) energy range. We argue that this anomaly is probably caused by a modification of the equation of state in the transition region between confined and deconfined matter. This observation may be considered as a new signal, in addition to the previously reported anomalies in the pion and strangeness production, of the onset of deconfinement located in the low SPS energy domain