7 research outputs found
Oscillating HBT radii and the time evolution of the source-√s NN = 200 GeV Au + Au data analyzed with azimuthally sensitive Buda-Lund hydro model
Identified particle spectra of pions, kaons and (anti)protons, and elliptic flow and azimuthal dependence of Bose-Einstein or HBT correlations of identified pions in sNN = 200 GeV Au + Au collisions is analyzed simultaneously using an ellipsoidally symmetric generalization of the Buda-Lund hydrodynamical model. The transverse flow is found to be faster in the reaction plane than out of plane, which results in a reaction zone that gets slightly more elongated in-plane than out of plane. © 2011 Pleiades Publishing, Ltd
Statistical and Dynamic Models of Charge Balance Functions
Charge balance functions, which identify balancing particle-antiparticle
pairs on a statistical basis, have been shown to be sensitive to whether
hadronization is delayed by several fm/c in relativistic heavy ion collisions.
Results from two classes of models are presented here, microscopic hadronic
models and thermal models. The microscopic models give results which are
contrary to recently published pi+pi- balance functions from the STAR
collaboration, whereas the thermal model roughly reproduce the experimental
results. This suggests that charge conservation is local at breakup, which is
in line with expectations for a delayed hadronization. Predictions are also
presented for balance functions binned as a function of Q_inv.Comment: 12 pages 6 figure
Anomalous radial expansion in central heavy-ion reactions
The expansion velocity profile in central heavy-ion reactions in the Fermi
energy domain is examined. The radial expansion is non-hubblean and in the
surface region it scales proportional to a higher exponent () of
the radius. The anomalous expansion velocity profile is accompanied by a power
law nucleon density profile in the surface region. Both these features of
central heavy-ion reactions disappear at higher energies, and the system
follows a uniform Hubble expansion ()
Centrality dependence of the expansion dynamics in Pb-Pb collisions at 158 A GeV/c
Two-particle correlation functions of negatively charged hadrons from Pb-Pb
collisions at 158 GeV/c per nucleon have been measured by the WA97 experiment
at the CERN SPS. A Coulomb correction procedure that assumes an expanding
source has been implemented. Within the framework of an expanding thermalized
source model the size and dynamical state of the collision fireball at
freeze-out have been reconstructed as a function of the centrality of the
collision. Less central collisions exhibit a different dynamics than central
ones: both transverse and longitudinal expansion velocities are slower, the
expansion duration is shorter and the system freezes out showing smaller
dimensions and higher temperature.Comment: 22 pages, 11 figures, Te
Bose-Einstein Correlations of Charged Kaons in Central Pb+Pb Collisions at
Bose-Einstein correlations of charged kaons were measured near mid-rapidity
in central Pb+Pb collisions at 158 AGeV by the NA49 experiment at the
CERN SPS. Source radii were extracted using the Yano-Koonin-Podgoretsky and
Bertsch-Pratt parameterizations. The results are compared to published pion
data. The measured dependence for kaons and pions is consistent with
collective transverse expansion of the source and a freeze-out time of about
9.5 .Comment: 14 pages with 7 figures, submitted to Phys. Lett.