3,036 research outputs found
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
Centrality and Energy Dependence of Proton, Light Fragment and Hyperon Production
Recent results of the NA49 collaboration are discussed. These include the
energy dependence of stopping and the production of the light fragments t and
3He. New data on the system size dependence of hyperon production at 40A and
158AGeV are also presented.Comment: 4 pages, Quark Matter 2006 proceeding
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
Femtoscopy correlations of kaons in collisions at LHC within hydrokinetic model
We provide, within the hydrokinetic model, a detailed investigation of kaon
interferometry in collisions at LHC energy (
TeV). Predictions are presented for 1D interferometry radii of and
pairs as well as for 3D femtoscopy scales in out, side and
long directions. The results are compared with existing pion interferometry
radii. We also make predictions for full LHC energy.Comment: 12 pages, 6 figure
Strange Particle Production from SIS to LHC
>1A review of meson emission in heavy ion collisions at incident energies
from SIS up to collider energies is presented. A statistical model assuming
chemical equilibrium and local strangeness conservation (i.e. strangeness
conservation per collision) explains most of the observed features.
Emphasis is put onto the study of and emission at low incident
energies. In the framework of this statistical model it is shown that the
experimentally observed equality of and rates at
``threshold-corrected'' energies is due to a
crossing of two excitation functions. Furthermore, the independence of the
to ratio on the number of participating nucleons observed between
SIS and RHIC is consistent with this model.
It is demonstrated that the production at SIS energies occurs
predominantly via strangeness exchange and this channel is approaching chemical
equilibrium. The observed maximum in the excitation function is
also seen in the ratio of strange to non-strange particle production. The
appearance of this maximum around 30 GeV is due to the energy
dependence of the chemical freeze-out parameters and .Comment: Presented at the International Workshop "On the Physics of the
Quark-Gluon Plasma", Palaiseau, France, September 2001. 10 pages, 8 figure
Transverse Momentum Spectra of and Mesons from Quark Gluon Plasma Hadronization in Nuclear Collisions
Recent results on transverse mass spectra of and
mesons in central Pb+Pb collisions at 158 AGeV are considered. It is
shown that those results support a hypothesis of statistical production of
charmonia at hadronization and suggest the early thermal freeze--out of
and mesons. Based on this approach the collective
transverse velocity of hadronizing quark gluon plasma is estimated to be
. Predictions for transverse mass spectra of hidden and
open charm mesons at SPS and RHIC are discussed.Comment: Four pages, one figur
THERMUS -- A Thermal Model Package for ROOT
THERMUS is a package of C++ classes and functions allowing
statistical-thermal model analyses of particle production in relativistic
heavy-ion collisions to be performed within the ROOT framework of analysis.
Calculations are possible within three statistical ensembles; a grand-canonical
treatment of the conserved charges B, S and Q, a fully canonical treatment of
the conserved charges, and a mixed-canonical ensemble combining a canonical
treatment of strangeness with a grand-canonical treatment of baryon number and
electric charge. THERMUS allows for the assignment of decay chains and detector
efficiencies specific to each particle yield, which enables sensible fitting of
model parameters to experimental data.Comment: to be published in Computer Physics Communication
Omega, J/psi and psi' Transverse Mass Spectra at RHIC
The transverse mass spectra of J/psi and psi' mesons and Omega hyperons
produced in central Au+Au collisions at RHIC energies are discussed within a
statistical model used successfully for the interpretation of the SPS results.
The comparison of the presented model with the future RHIC data should serve as
a further crucial test of the hypothesis of statistical production of charmonia
at hadronization. Finally, in case of validity, the approach should allow to
estimate the mean transverse flow velocity at the quark gluon plasma
hadronization.Comment: revised version to appear in Phys. Lett.
Recombination of Shower Partons at High in Heavy-Ion Collisions
A formalism for hadron production at high \pt in heavy-ion collisions has
been developed such that all partons hadronize by recombination. The
fragmentation of a hard parton is accounted for by the recombination of shower
partons that it creates. Such shower partons can also recombine with the
thermal partons to form particles that dominate over all other possible modes
of hadronization in the GeV range. The results for the high \pt
spectra of pion, kaon, and proton agree well with experiments. Energy loss of
partons in the dense medium is taken into account on the average by an
effective parameter by fitting data, and is found to be universal independent
of the type of particles produced, as it should. Due to the recombination of
thermal and shower partons, the structure of jets produced in nuclear
collisions is different from that in collisions. The consequence on
same-side correlations is discussed.Comment: This revised version contains minor changes and a new figure
- …