Hydrodynamics and perfect fluids: uniform description of soft observables in Au+Au collisions at RHIC

It is argued that the use of the initial Gaussian energy density profile for hydrodynamics leads to much better uniform description of the RHIC heavy-ion data than the use of the standard initial condition obtained from the Glauber model. With the modified Gaussian initial conditions we successfully reproduce the transverse-momentum spectra, v2, and the pionic HBT radii (including their azimuthal dependence). The emerging consistent picture of hadron production hints that a solution of the long standing RHIC HBT puzzle has been found.Comment: Talk presented by WF at the XXXVIII International Symposium on Multiparticle Physic

Describing transverse dynamics and space-time evolution at RHIC in a hydrodynamic model with statistical hadronization

A hydrodynamic model coupled to the statistical hadronization code Therminator is used to study a set of observables in the soft sector at RHIC. A satisfactory description of the pT-spectra and elliptic flow is obtained, similarly to other hydrodynamic models. With the Gaussian initial conditions the transverse femtoscopic radii are also reproduced, providing a possible solution of the RHIC HBT puzzle.Comment: to appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse

Solution of the RHIC HBT puzzle with Gaussian initial conditions

It is argued that the consistent description of the transverse-momentum spectra, elliptic flow, and the HBT radii in the relativistic heavy-ion collisions studied at RHIC may be obtained within the hydrodynamic model if one uses the Gaussian profile for the initial energy density in the transverse plane. Moreover, we show that the results obtained in the scenario with an early start of hydrodynamics (at the proper time tau0 = 0.25 fm) are practically equivalent to the results obtained in the model where the hydrodynamics is preceded by the free-streaming stage of partons (in the proper time interval 0.25 fm < tau < 1 fm) which suddenly equilibrate and with the help of the Landau matching conditions are transformed into the hydrodynamic regime (at the proper time tau0 = 1 fm).Comment: talk presented by WF at SQM2008 Conferenc

Early dynamics of transversally thermalized matter

We argue that the idea that the parton system created in relativistic heavy-ion collisions is formed in a state with transverse momenta close to thermodynamic equilibrium and its subsequent dynamics at early times is dominated by pure transverse hydrodynamics of the perfect fluid is compatible with the data collected at RHIC. This scenario of early parton dynamics may help to solve the problem of early equilibration.Comment: 4 pages, 2 figures, Talk given by M. Chojnacki at Quark Matter 2008, Jaipur, Indi

Rapid hydrodynamic expansion in relativistic heavy-ion collisions

Hydrodynamic expansion of the hot fireball created in relativistic Au-Au collisions at 200GeV in 3+1-dimensions is studied. We obtain a simultaneous, satisfactory description of the transverse momentum spectra, elliptic flow and pion correlation radii for different collision centralities and different rapidities. Early initial time of the evolution is required to reproduce the interferometry data, which provides a strong indication of the early onset of collectivity. We can also constraint the shape of the initial energy density in the beam direction, with a relatively high initial energy density at the center of the fireball.Comment: 10 pages, 13 fig