171 research outputs found
Study of dielectron production in C+C collisions at 1 AGeV
The emission of e+e- pairs from C+C collisions at an incident energy of 1 GeV
per nucleon has been investigated. The measured production probabilities,
spanning from the pi0-Dalitz to the rho/omega! invariant-mass region, display a
strong excess above the cocktail of standard hadronic sources. The
bombarding-energy dependence of this excess is found to scale like pion
production, rather than like eta production. The data are in good agreement
with results obtained in the former DLS experiment.Comment: submitted to Physics Letters
The ASY-EOS experiment at GSI: investigating the symmetry energy at supra-saturation densities
The elliptic-flow ratio of neutrons with respect to protons in reactions of
neutron rich heavy-ions systems at intermediate energies has been proposed as
an observable sensitive to the strength of the symmetry term in the nuclear
Equation Of State (EOS) at supra-saturation densities. The recent results
obtained from the existing FOPI/LAND data for Au+Au collisions
at 400 MeV/nucleon in comparison with the UrQMD model allowed a first estimate
of the symmetry term of the EOS but suffer from a considerable statistical
uncertainty. In order to obtain an improved data set for Au+Au collisions and
to extend the study to other systems, a new experiment was carried out at the
GSI laboratory by the ASY-EOS collaboration in May 2011.Comment: Talk given by P. Russotto at the 11th International Conference on
Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June 1,
2012. To appear in the NN2012 Proceedings in Journal of Physics: Conference
Series (JPCS
The High-Acceptance Dielectron Spectrometer HADES
HADES is a versatile magnetic spectrometer aimed at studying dielectron
production in pion, proton and heavy-ion induced collisions. Its main features
include a ring imaging gas Cherenkov detector for electron-hadron
discrimination, a tracking system consisting of a set of 6 superconducting
coils producing a toroidal field and drift chambers and a multiplicity and
electron trigger array for additional electron-hadron discrimination and event
characterization. A two-stage trigger system enhances events containing
electrons. The physics program is focused on the investigation of hadron
properties in nuclei and in the hot and dense hadronic matter. The detector
system is characterized by an 85% azimuthal coverage over a polar angle
interval from 18 to 85 degree, a single electron efficiency of 50% and a vector
meson mass resolution of 2.5%. Identification of pions, kaons and protons is
achieved combining time-of-flight and energy loss measurements over a large
momentum range. This paper describes the main features and the performance of
the detector system
Study of e+,e− production in elementary and nuclear collisions near the production threshold with HADES
HADES is a second generation experiment designed to study dielectron production in proton, pion, and heavy ion induced reactions at the GSI accelerator facility in Darmstadt. The physics programme of HADES is focused on in-medium properties of the light vector mesons. In this contribution we present status of the HADES experiment, demonstrate its capability to identify rare dielectron signal, show first experimental results obtained from C+C reactions at 2 A GeV and shortly discuss physics programme of up-coming experimental runs. © 2004 Elsevier B.V. All rights reserved. 53 1 49 58 Cited By :1
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