No abstract available

[en] Time evolution of the momentum spectra, Bose-Einstein correlation functions and averaged phase-space densities (APSD) is analyzed within hydrodynamic and kinetic models. The results shed light on behavior of the interferometry volumes and APSD in A+A collisions at different energies and for different nuclei

[en] A simple model of non-femtoscopic particle correlations in proton-proton collisions is proposed. The model takes into account correlations induced by the conservation laws as well as correlations induced by minijets. It gives reasonable description of the non-femtoscopic correlation functions of identical pions that have been obtained from the PHOJET event generator simulations of proton-proton collision events at √ s = 900 GeV and utilized as correlation baseline by the ALICE Collaboration.

[en] The hydrokinetic model is applied to restore the initial conditions and space-time picture of the matter evolution in central Au + Au collisions at the top RHIC energy. The analysis is based on the detailed reproduction of the pion and kaon momentum spectra and femtoscopic data in whole interval of the transverse momenta studied by both STAR and PHENIX collaborations. A good description of the pion and kaon transverse momentum spectra and interferometry radii is reached with both initial energy density profiles motivated by the Glauber and Color Glass Condensate (CGC) models, however, at different energy densities.

[en] The hydrokinetic approach that incorporates hydrodynamic expansion of the systems formed in A+A collisions and their dynamical decoupling is applied to restore the initial conditions and space-time picture of the matter evolution in central Au+Au collisions at the top Relativistic Heavy Ion Collider energy. The analysis is based on the detailed reproduction of the pion and kaon momentum spectra and femtoscopic data in whole interval of the transverse momenta studied by both the STAR and the PHENIX collaborations. The fitting procedure utilizes the two parameters: the maximal energy density at supposed thermalization time 1 fm/c and the strength of the prethermal flows developed to this time. The quark-gluon plasma and hadronic gas is supposed to be in complete local equilibrium above the chemical freeze-out temperature T_ch=165 MeV with the equation of states (EoS) at high temperatures as in the lattice QCD. Below T_ch the EoS in the expanding and gradually decoupling fluid depends on the composition of the hadron-resonance gas at each space-time point and accounts for decays of resonances into the nonequilibrated medium. A good description of the pion and kaon transverse momentum spectra and interferometry radii is reached at both used initial energy density profiles motivated by the Glauber and color glass condensate models, however, at different initial energy densities. The discussion as for the approximate pion and kaon m_T scaling for the interferometry radii is based on a comparison of the emission functions for these particles.

[en] A simple approach is proposed allowing actual calculations of the preequilibrium dynamics in ultrarelativistic heavy-ion collisions to be performed for a far-from-equilibrium initial state. The method is based on the phenomenological macroscopic equations that describe the relaxation dynamics of the energy-momentum tensor and are motivated by Boltzmann kinetics in the relaxation-time approximation. It gives the possibility to match smoothly a nonthermal initial state to the hydrodynamics of the quark gluon plasma. The model contains two parameters, the duration of the prehydrodynamic stage and the initial value of the relaxation-time parameter, and allows one to assess the energy-momentum tensor at a supposed time of initialization of the hydrodynamics.

[en] The ability of the ALICE detector for determination of the space-time characteristics of particle production in heavy-ion collisions at LHC from measurements of the correlation functions of identical and non-identical particles at small relative velocities is discussed. The possibility to use the correlations of non-identical particles for a direct determination of the delays in emission of various particle species at time scales as small as 10^-23 s is demonstrated. The influence of the multi-boson effects on pion multiplicities, single-pion spectra and two-pion correlation functions is discussed. (author)

[en] A study of energy behavior of the pion spectra and interferometry scales is carried out for the top SPS, RHIC and for LHC energies within the hydrokinetic approach. The main mechanisms that lead to the paradoxical, at first sight, dependence of the interferometry scales with an energy growth, in particular, a decrease R_out/R_side ratio, are exposed. The hydrokinetic predictions for the HBT radii at LHC energies are compared with the recent results of the ALICE experiment.

[en] Using the hydrokinetic model of pionic emission in heavy ion collisions, we study the effects of continuous particle emission for 3D azimuthal symmetric Bjorken-type expansion. We describe RHIC pion data in central A + A collisions and make predictions for LHC based on the hydrokinetic model and initial conditions taken from the color glass condensate model.

[en] We develop a combined hydro-kinetic approach which incorporates a hydrodynamical expansion of the systems formed in A+A collisions and their dynamical decoupling described by escape probabilities. The method corresponds to a generalized relaxation time (τ_rel) approximation for the Boltzmann equation applied to inhomogeneous expanding systems; at small τ_rel it also allows one to catch the viscous effects in hadronic component-hadron-resonance gas. We demonstrate how the approximation of sudden freeze-out can be obtained within this dynamical picture of continuous emission and find that hypersurfaces, corresponding to a sharp freeze-out limit, are momentum dependent. The pion m_T spectra are computed in the developed hydro-kinetic model, and compared with those obtained from ideal hydrodynamics with the Cooper-Frye isothermal prescription. Our results indicate that there does not exist a universal freeze-out temperature for pions with different momenta, and support an earlier decoupling of higher p_T particles. By performing numerical simulations for various initial conditions and equations of state we identify several characteristic features of the bulk QCD matter evolution preferred in view of the current analysis of heavy ion collisions at RHIC energies