65 research outputs found
Blast-wave snapshots from RHIC
I present fits with the so-called blast-wave model to single-particle spectra
and HBT correlations from Au+Au collisions at a CMS energy of 130 AGeV. There
is only little choice of freeze-out temperature and transverse flow velocity
for which the model fits both the identified spectra and the correlation radii
just well enough not to be excluded. The observed steep M_t dependence of
R_side leads to a temperature which it is problematic to interpret. The
applicability of the model for the freeze-out description is thus questioned.Comment: 4 pages, 2 figures, proceedings of 38 Rencontres de Moriond, QCD and
hadronic interaction
Understanding of the freeze-out in ultra-relativistic heavy-ion collisions
I discuss the quantities and effects important for the freeze-out and outline
a formalism for the description of continuous decoupling of particles from the
fireball. Then I present a calculation of the scattering rates of pions at
various temperatures and argue that it is important to take continuous particle
decoupling into account when modelling the collision dynamics.Comment: 4 pages, 2 figures, Talk given at the 2nd Warsaw meeting on
correlations and resonances, Oct. 15-18, 2003, Warsaw, Polan
Fine-Tuning Two-Particle Interferometry I: Effects from Temperature Gradients in the Source
A comprehensive model study of Bose-Einstein correlation radii in heavy ion
collisions is presented. The starting point is a longitudinally and
transversally expanding fireball, represented at freeze-out by an azimuthally
symmetric emission function. The freeze-out temperature is allowed to feature
transverse and temporal gradients. Their effects on the correlation radii are
studied. In particular, we evaluate numerically their dependence on the
transverse mass of the particle pairs and check a recent suggestion, based on
analytical approximations, that for certain reasonable source parameters all
three correlation radii satisfy simultaneously a 1/\sqrt{M_\perp} scaling.Comment: 22 pages, 8 figures, epsf; replaced with the revised first part of
the original study, the revised second part (concerning opaque sources) can
be found under nucl-th/980501
Event shape sorting
We propose a novel method for sorting events of multiparticle production
according to the azimuthal anisotropy of their momentum distribution. Although
the method is quite general, we advocate its use in analysis of
ultra-relativistic heavy-ion collisions where large number of hadrons is
produced. The advantage of our method is that it can automatically sort out
samples of events with histograms that indicate similar distributions of
hadrons. It takes into account the whole measured histograms with all orders of
anisotropy instead of a specific observable (e.g. , , ). It can
be used for more exclusive experimental studies of flow anisotropies which are
then more easily compared to theoretical calculations. It may also be useful in
the construction of mixed-events background for correlation studies as it
allows to select events with similar momentum distribution.Comment: 11 pages, 7 figures, to appear in European Physical Journal A,
section added in v2 with analysis of AMPT-generated event
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