3,127 research outputs found
Statistical hadronization of charm at SPS, RHIC and LHC
We study the production of charmonia and charmed hadrons for nucleus-nucleus
collisions at SPS, RHIC, and LHC energies within the framework of the
statistical hadronization model. Results from this model are compared to the
observed centrality dependence of J/psi production at SPS energy. We further
provide predictions for the centrality dependence of the production of open and
hidden charm mesons at RHIC and LHC.Comment: Contribution to Quark Matter 2002, 4 pages, 3 figures; revised
version including charmed hyperons (omitted in v1
Probing the Phase Boundary between Hadronic Matter and the Quark-Gluon-Plasma in Relativistic Heavy Ion Collisions
We discuss recent data on particle production with emphasis on the degree of
thermal and chemical equilibration achieved. The data are interpreted in terms
of a resonance gas model. The phase boundary constructed between the resonance
gas and the quark-gluon plasma is shown to be very close to the deduced
parameters characterizing the hadronic fireball at freeze-out.Comment: 7 pages, latex, 6 figures, 1 table submitted to Nuclear Physics A,
dedicated to Gerry Brown in honor of his 70th birthda
Production of Strange Clusters and Strange Matter in Nucleus-Nucleus Collisions at the AGS
Production probabilities for strange clusters and strange matter in Au+Au
collisions at AGS energy are obtained in the thermal fireball model. The only
parameters of the model, the baryon chemical potential and temperature, were
determined from a description of the rather complete set of hadron yields from
Si+nucleus collisions at the AGS. For the production of light nuclear fragments
and strange clusters the results are similar to recent coalescence model
calculations. Strange matter production with baryon number larger than 10 is
predicted to be much smaller than any current experimental sensitivities.Comment: 9 Pages (no figures
On Charm Production near the Phase Boundary
We discuss aspects of the statistical hadronization model for the production
of mesons with open and hidden charm in ultra-relativistic nuclear collisions.
Emphasis is placed on what can be inferred from the dependence of the yield of
charmonia on the number of participants in the collisions.Comment: Invited Paper, NAN Conference, Darmstadt, Oct. 2000, final version,
expanded discussion on results at collider energies, Nucl. Phys. A. (in
print). Dedicated to Achim Richter in honor of his 60th birthda
(Non)Thermal Aspects of Charmonium Production and a New Look at J/ Suppression
To investigate a recent proposal that J/ production in
ultra-relativistic nuclear collisions is of thermal origin we have reanalyzed
the data from the NA38/50 collaboration within a thermal model including charm.
Comparison of the calculated with measured yields demonstrates the non-thermal
origin of hidden charm production at SPS energy. However, the ratio
/(J/ exhibits, in central nucleus-nucleus collisions, thermal
features which lead us to a new interpretation of open charm and charmonium
production at SPS energy. Implications for RHIC and LHC energy measurements
will be discussed.Comment: 12 pages, 3 eps figures, final version with slight corrections, Phys.
Lett. B (in print
Towards strangeness saturation in central heavy-ion collisions at high energies
Analyses of the centrality binned identified hadron multiplicities at SPS and
RHIC within the statistical-thermal model point to strangeness saturation with
increasing centrality and energy.Comment: 4 pages, 2 figures. Presented at the 16th International Conference on
Ultra-Relativistic Nucleus-Nucleus Collisions, Nantes, France, 18-24 July,
200
Thermal description of hadron production in e+e- collisions revisited
We present a comprehensive analysis of hadron production in e+e- collisions
at different center-of-mass energies in the framework of the statistical model
of the hadron resonance gas. The model is formulated in the canonical ensemble
with exact conservation of all relevant quantum numbers. The parameters of the
underlying model were determined using a fit to the average multiplicities of
the latest measurements at = 10, 29-35, 91 and 130-200 GeV. The
results demonstrate that, within the accuracy of the experiments, none of the
data sets is satisfactorily described with this approach, calling into question
the notion that particle production in e+e- collisions is thermal in origin.Comment: 13 pages, 3 figures; v2: final version accepted for publication in
Phys. Lett.
Hadron production in Au-Au collisions at RHIC
We present an analysis of particle production yields measured in central
Au-Au collisions at RHIC in the framework of the statistical thermal model. We
demonstrate that the model extrapolated from previous analyses at SPS and AGS
energy is in good agreement with the available experimental data at GeV implying a high degree of chemical equilibration. Performing a
fit to the data, the range of thermal parameters at chemical freezeout
is determined. At present, the best agreement of the model and the data is
obtained with the baryon chemical potential MeV and
temperature MeV. More ratios, such as multistrange baryon to
meson, would be required to further constrain the chemical freezeout
conditions. Extrapolating thermal parameters to higher energy, the predictions
of the model for particle production in Au-Au reactions at GeV
are also given.Comment: Final version, minor changes to text and figures. To appear in Phys.
Lett.
Particle Production in Heavy Ion Collisions
The status of thermal model descriptions of particle production in heavy ion
collisions is presented. We discuss the formulation of statistical models with
different implementation of the conservation laws and indicate their
applicability in heavy ion and elementary particle collisions. We analyze
experimental data on hadronic abundances obtained in ultrarelativistic heavy
ion collisions, in a very broad energy range starting from RHIC/BNL ( A GeV), SPS/CERN ( A GeV) up to AGS/BNL ( A GeV) and SIS/GSI ( A GeV) to test equilibration
of the fireball created in the collision. We argue that the statistical
approach provides a very satisfactory description of experimental data covering
this wide energy range. Any deviations of the model predictions from the data
are indicated. We discuss the unified description of particle chemical
freeze--out and the excitation functions of different particle species. At SPS
and RHIC energy the relation of freeze--out parameters with the QCD phase
boundary is analyzed. Furthermore, the application of the extended statistical
model to quantitative understanding of open and hidden charm hadron yields is
considered.Comment: Invited review for Quark Gluon Plasma 3, eds. R. C. Hwa and Xin-Nian
Wang, World Scientific Publishin
The thermal model on the verge of the ultimate test: particle production in Pb-Pb collisions at the LHC
We investigate the production of hadrons in nuclear collisions within the
framework of the thermal (or statistical hadronization) model. We discuss both
the ligh-quark hadrons as well as charmonium and provide predictions for the
LHC energy. Even as its exact magnitude is dependent on the charm production
cross section, not yet measured in Pb-Pb collisions, we can confidently predict
that at the LHC the nuclear modification factor of charmonium as a function of
centrality is larger than that observed at RHIC and compare the experimental
results to these predictions.Comment: 4 pages, 3 figures; proceedings of QM201
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