Single-freeze-out model for ultra relativistic heavy-ion collisions at sNN=2.76\sqrt{s_{\rm NN}}=2.76 TeV and the LHC proton puzzle

The single-freeze-out model with parametrized hypersurface and flow geometry is employed to analyze the transverse-momentum spectra of hadrons produced in the Pb+Pb collisions at the collision energy of {$\sqrt{s_{\rm NN}}=2.76$ TeV} at the CERN Large Hadron Collider (LHC). With the notable exception for protons and antiprotons, we find a very good agreement between the model results and the data for the measured hadron species. The additional analysis of the HBT radii of pions helps us to select, from several different types of freeze-out studied in this work, the most realistic form of the freeze-out hypersurface. We find that discrepancy ratio between the model and experiment for the proton/antiproton spectra depends on $p_T$, dropping from 2 in the soft region to 1 around $p_T=1.5$ GeV.Comment: 9 pages, 10 figure

Matter-induced hadronic processes

Two examples of ``exotic'' phenomena which become possible and important in the presence of nuclear matter are discussed: omega -> pi pi decay, and rho-omega mixing. Significance of these processes for the low-mass dilepton production in relativistic heavy-ion collisions is indicated.Comment: 8 pages, uses aipproc.cls, talk presented by W. Florkowski at the International Workshop on Hadron Physics "Effective Theories of Low Energy QCD", Coimbra, Portugal, September 10-15, 199

Balance functions from a thermal model

A calculation of the pion balance functions in a thermal model is presented. The total result consists of resonance and non-resonance parts. A satisfactory agreement with the data on Au+Au collisions at 130 GeV is found.Comment: talk presented by WF during the 3rd Budapest Winter School on Heavy-Ions, Dec. 8-11, 2003, Budapest, Hungar

Transverse hydrodynamics with sudden hadronization -- production of strangeness

We consider a physical scenario for ultra-relativistic heavy-ion collisions where, at the early stage, only transverse degrees of freedom of partons are thermalized, while the longitudinal motion is described by free streaming. When the energy density of the partonic system drops to a certain critical value, the partons hadronize and the newly formed hadronic system freezes out. This sudden change is described with the help of the Landau matching conditions followed by the simulations done with THERMINATOR. The proposed scenario reproduces well the transverse-momentum spectra, the elliptic flow coefficient v2, and the HBT radii of pions and kaons studied at RHIC (Au+Au collisions at the top beam energy). It also reproduces quite well the transverse-momentum spectra of hyperons.Comment: talk presented by WF at the Strangeness in Quark Matter Conference, Buzios, Brazil, Sept. 27 - oct. 2, 200