One of the main goals of the HADES experiment is to achieve a detailed understanding of dielectron emission from hadronic systems at moderate bombarding energies. Results obtained on electron pair ...production in elementary
N+
N collisions pave the way to a better understanding of the origin of the pair excess seen in heavy-ion collisions. This puzzling excess, reported first by the former DLS experiment, is now being investigated systematically by HADES.
We present an analysis of the hyperons Λ(1405) and Σ(1385)
+
for p+p reactions at 3.5 GeV kinetic beam energy. The data were taken with the
H
igh
A
cceptance
D
i-
E
lectron
S
pectrometer (HADES). A ...Λ(1405) signal could be reconstructed in both charged decay channels Λ(1405)→Σ
±
π
∓
. The obtained statistics of the Σ(1385)
+
signal allows also differential studies.
Discusses the rules and methodology of introducing a new job description for an electronic resources librarian in an academic library in Poland. Indicates that a precise job description and its ...implementation in a job position linked to the strategic goals of an organisation make the structure clear and, consequently, efficient.
We report first results on a deep subthreshold production of the doubly strange hyperon Xi- in a heavy-ion reaction. At a beam energy of 1.76A GeV the reaction Ar+KCl was studied with the High ...Acceptance Di-Electron Spectrometer at SIS18/GSI. A high-statistics and high-purity Lambda sample was collected, allowing for the investigation of the decay channel Xi--->Lambdapi-. The deduced Xi-/(Lambda+Sigma0) production ratio of (5.6±1.2-1.7+1.8)×10-3 is significantly larger than available model predictions.
The aim of the present analysis is to determine the relative production cross sections of the Λ(1405) and Σ(1385)
0
resonances in p+p collisions at E
kin
= 3.5 GeV measured with HADES. Upper and ...lower limits have been determined for the ratio
. The knowledge of this ratio is an essential input for the analysis of the decay Λ(1405)→Σ
±
π
∓
, where an unambiguous separation of the Λ(1405) and Σ(1385)
0
signals is not possible.
We report on recent data of e+e− pair emission in proton nucleus collisions at energies above the light vector meson production thresholds. Invariant mass distributions for the p+Nb system at Ekin ...3.5 GeV are compared to data from elementary p+p reactions at the same beam energy. We observe a constant π0/ω yield ratio for both systems but an excess in the mass region above the π0 mass. Furthermore we present here the normalization procedure that was applied to p+Nb collisions by measuring the production of negative pions in the HADES acceptance.
HADES is a secondary generation experiment operated at GSI Darmstadt with the main goal to study dielectron production in proton, pion and heavy ion induced reactions. The first part of the HADES ...mission is to reinvestigate the puzzling pair excess measured by the DLS collaboration in C+C and Ca+Ca collisions at 1A GeV. For this purpose dedicated measurements with the C+C system at 1 and 2A GeV were performed. The pair excess above a cocktail of free hadronic decays has been extracted and compared to the one measured by DLS. Furthermore, the excess is confronted with predictions of various model calculations.
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 π0-Dalitz to the ρ/ω ...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.
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