3,666 research outputs found
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
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