10 research outputs found
Strangeness Production at SIS measured with HADES
n this paper we review the recent results on strangeness production measured
by HADES in the Ar+KCl system at a beam energy of 1.756 AGeV. A detailed
comparison of the measured hadron yields with the statistical model is also
discussed.Comment: submitted to Nucl. Phys. A, Proceedings of the 10th International
Conference on Nucleus-Nucleus Collision, Beijing China 200
Low-mass dielectrons from the PHENIX experiment at RHIC
The production of the low-mass dielectrons is considered to be a powerful
tool to study the properties of the hot and dense matter created in the
ultra-relativistic heavy-ion collisions. We present the preliminary results on
the first measurements of the low-mass dielectron continuum in Au+Au collisions
and the phi meson production measured in Au+Au and d+Au collisions at
sqrt{s_NN} = 200 GeV performed by the PHENIX experiment.Comment: 6 pages, 12 figures, conference proceedings for QNP06 (5-10 June,
2006, Madrid
Large mass dilepton production from jet-dilepton conversion in the quark-gluon plasma
We calculate the production of large mass dileptons from the passage of jets
passing through the quark-gluon plasma. Using the relativistic kinetic theory,
we rigorously derive the production rate for the jet-dilepton conversion in the
hot medium. The jet-dilepton conversion is compared with the thermal dilepton
emission and the Drell-Yan process. The contribution of the jet-dilepton
conversion is not prominent for all values of the invariant mass , and the
Drell-Yan process is found to dominate over the thermal dilepton emission and
the jet-dilepton conversion for 2.5 GeV at RHIC. The jet-dilepton
conversion is the dominant source of large mass dileptons in the range of 4 GeV
10 GeV at LHC.Comment: 2 figure
Microscopic calculations of stopping and flow from 160AMeV to 160AGeV
The behavior of hadronic matter at high baryon densities is studied within
Ultrarelativistic Quantum Molecular Dynamics (URQMD). Baryonic stopping is
observed for Au+Au collisions from SIS up to SPS energies. The excitation
function of flow shows strong sensitivities to the underlying equation of state
(EOS), allowing for systematic studies of the EOS. Effects of a density
dependent pole of the -meson propagator on dilepton spectra are studied
for different systems and centralities at CERN energies.Comment: Proceedings of the Quark Matter '96 Conference, Heidelberg, German
- nucleus bound states in Walecka model
Possible formation of nucleus bound state is studied in the framework
of Walecka model. The bound states are found in different nuclei ranging from
to . These bound states may have a direct bearing on the
recent experiments on the photoproduction of meson in the nuclear
medium.Comment: RevTeX fil
Reinterpretation of Thermal Dilepton Emission Rate by Spectral Functions
We reinterpret the dilepton emission rate from a hadronic gas expected to be
produced in heavy ion collisions in terms of the spectral functions available
from the annihilation and the lepton decays experiments. We
take into account all possible hadronic state especially the multi-pion
contributions to the dilepton emission and the parity mixing phenomenon due to
the soft final-state corrections. A new compilation of the experimental data
for the spectral functions is presented.Comment: 12 pages in LaTeX, two uuencoded postscript figure
Photon Production from a Quark--Gluon Plasma
In-medium interactions of a particle in a hot plasma are considered in the
framework of thermal field theory. The formalism to calculate gauge invariant
rates for photon and dilepton production from the medium is given. In the
application to a QED plasma, astrophysical consequences are pointed out. The
photon production rate from strongly interacting quarks in the quark--gluon
plasma, which might be formed in ultrarelativistic heavy ion collisions, is
calculated in the previously unaccessible regime of photon energies of the
order of the plasma temperature. For temperatures below the chiral phase
transition, an effective field theory incorporating dynamical chiral symmetry
breaking is employed, and perturbative QCD at higher temperatures. A smooth
transition between both regions is obtained. The relevance to the soft photon
problem and to high energy heavy ion experiments is discussed.Comment: Paper in ReVTeX. Figures and complete paper available via anonymous
ftp, ftp://tpri6c.gsi.de/pub/phenning/hq95ga
Equation of State, Radial Flow and Freeze-out in High Energy Heavy Ion Collisions
We have shown that recent experimental data on radial flow, both from AGS and
SPS energies, are in agreement with the Equation of State (EOS) including the
QCD phase transition. New hydro-kinetic model (HKM) is developed, which
incorporates hydrodynamical treatment of expansion and proper kinetics of the
freeze-out. We show that the freeze-out surfaces for different secondaries and
different collisions are very different, and they are not at all isotherms (as
was assumed in most previous hydro works). Comparison of HKM results with
cascade-based event generator RQMD is also made in some details: we found that
both EOS and flow are in rather good agreement, while the space-time picture is
still somewhat different