172 research outputs found
Non-identical particle correlation analysis as a probe of transverse flow
Non-identical two particle correlation functions probe asymmetries between
the average space-time emission points of different particle species. The
system collective expansion would produce such asymmetry because massive
particles, such as protons, are on average more pushed towards the edge of the
system, than lighter ones, i.e. pions. Measuring pion-kaon, pion-proton and
kaon-proton correlation functions, using the STAR detector, we show that the
data are consistent with the effect of transverse flow in Au-Au collisions at
GeV.Comment: 4 pages, 2 figures, 1 table, Contribution to Quark Matter 2002,
Nantes, France, July 200
Observable implications of geometrical and dynamical aspects of freeze-out in heavy ion collisions
Using an analytical parameterization of hadronic freeze-out in relativistic
heavy ion collisions, we present a detailed study of the connections between
features of the freeze-out configuration and physical observables. We focus
especially on anisotropic freeze-out configurations (expected in general for
collisions at finite impact parameter), azimuthally-sensitive HBT
interferometry, and final-state interactions between non-identical particles.
Model calculations are compared with data taken in the first year of running at
RHIC; while not perfect, good agreement is found, raising the hope that a
consistent understanding of the full freeze-out scenario at RHIC is possible,
an important first step towards understanding the physics of the system prior
to freeze-out.Comment: 36 pages, 56 figures, 2 tables; version accepted for publication in
PRC: some figures, references and discussion added; now also discusses
classical versus quantum statistic
Space-time analysis of reaction at RHIC
Space-time information about the Au-Au collisions produced at RHIC are key
tools to understand the evolution of the system and especially assess the
presence of collective behaviors. Using a parameterization of the system's
final state relying on collective expansion, we show that pion source radii can
be tied together with transverse mass spectra and elliptic flow within the same
framework. The consistency between these different measures provide a solid
ground to understand the characteristics of collective flow and especially the
possible peculiar behavior of particles such as Xi, Omega or phi. The validity
of the short time scales that are extracted from fits to the pion source size
is also addressed. The wealth of new data that will soon be available from
Au-Au collisions at sqrt{s_{NN}} = 200 GeV, will provide a stringet test of the
space-time analysis framework developped in these proceedings.Comment: Invited talk given at the SQM2003 conference (March 2003), to be
published in Journal of Physics G. 10 pages, 3 figure
Hard spectra and QCD matter: experimental review
The most significant experimental results on hadron spectra at large
transverse momentum available at the time of Quark Matter 2004 conference are
reviewed. Emphasis is put on those measurements that provide insights on the
properties of the QCD media, ``Quark Gluon Plasma'' and ``Color Glass
Condensate'', expected to be present in nucleus-nucleus collisions at collider
energies.Comment: 2 plots updated. Minor changes in tex
Emission angle dependent pion interferometry at RHIC and beyond
We use hydrodynamics to generate freeze-out configurations for non-central
heavy-ion collisions at present and future collider energies. Such collisions
are known to produce strong elliptic flow. The accompanying space-time
structure of the source at freeze-out is analyzed using pion interferometry.
Between RHIC and LHC energies the source deformation in the transverse plane
changes sign. This leaves characteristic signatures in the emission angle
dependence of the HBT radii.Comment: Minor changes (some references and discussion added), accepted by
Physics Letters
Hydrodynamic afterburner for the CGC at RHIC
Firstly, we give a short review about the hydrodynamic model and its
application to the elliptic flow phenomena in relativistic heavy ion
collisions. Secondly, we show the first approach to construct a unified model
for the description of the dynamics in relativistic heavy ion collisions.Comment: 15 pages, 7 figures, invited talk presented at "Hot Quarks 2004",
July 18-24, 2004, Taos Valley, NM, US
Bulk properties and flow
In this report, I summarize the experimental results on {\bf bulk properties
and flow} presented at Quark Matter 2004. It is organized in four sections: 1)
Initial condition and stopping; 2) Particle spectra and freeze-outs; 3)
Anisotropic flow; 4) Outlook for future measurements.Comment: 10 pages, 4 figures, "Rapporteur-Conference Highlights", Quark Matter
2004, Oakland, January 11-1
Detector and Front-end electronics for ALICE and STAR silicon strip layers
Detector modules consisting of Silicon Strip Detector (SSD) and Front End Electronics (FEE) assembly have been designed in order to provide the two outer layers of the ALICE Inner Tracker System (ITS) [1] as well as the outer layer of the STAR Silicon Vertex Tracker (SVT) [2]. Several prototypes have beenproduced and tested in the SPS and PS beam at CERN to validate the final design. Double-sided, AC-coupled SSD detectors provided by two different manufacturers and also a pair of single-sided SSD have been asssociated to new low-power CMOS ALICE128C ASIC chips in a new detector module assembly. The same detectors have also been associated to current Viking electronics for reference purpose. These prototype detector modules are described and some first results are presented
Strangeness Report
The paper provides a short report on strangeness production in
ultrarelativistic nucleus-nucleus collision, with the main stress on strange
particle abundances.Comment: Proceedings of Quark Matter 200
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