The High Acceptance Di-Electron Spectrometer (HADES) at the GSI Helmholtzzentrum für Schwerionenforschung investigates dilepton and strangeness production in elementary and heavy-ion collisions. In ...April - May 2012 HADES recorded 7 billion Au+Au events at a beam energy of 1.23 GeV u with the highest multiplicities measured so far. The track reconstruction and particle identification in the high track density environment are challenging. The most important detector component for lepton identification is the Ring Imaging Cherenkov detector. Its main purpose is the separation of electrons and positrons from large background of charged hadrons produced in heavy-ion collisions. In order to improve lepton identification this backtracking algorithm was developed. In this contribution we will show the results of the algorithm compared to the currently applied method for e+ -identification. Efficiency and purity of a reconstructed e+ - sample will be discussed as well.
Zusammenfassung
Seit dem ersten Auftauchen des neuartigen SARS-CoV-2 Virus im November 2019 haben sich Spekulationen zu seinem Ursprung und seiner rasanten Verbreitung im internationalen Diskurs ...verfestigt. Während die wissenschaftliche Grundlage zum Ursprung des Virus nicht eindeutig ist, ist schnell der internationale Wildtierhandel in Verruf geraten. In diesem Artikel wird auf eben jene wissenschaftlichen Grundlagen eingegangen, die unterschiedliche Theorien zum Ursprung des Virus untermauern bzw. widerlegen. Außerdem geht der Artikel auf die Rolle der Washingtoner Artenschutzkonvention (CITES) in der Eindämmung der Pandemie und der Verhinderung zukünftiger Pandemien ein.
Lepton pairs are considered as an ideal probe to access the microscopic properties of strongly-interacting matter under extreme conditions of temperature and density. The spectral distribution of ...lepton pairs in the region below the low mass vector mesons is characterized by an excess radiation above contributions from late meson decays, the so-called hadronic cocktail. It is theoretically understood as a thermal radiation based on Vector Meson Dominance assuming a strong broadening of the in-medium spectral function due to coupling to baryons and anti-baryons.
In continuation of a systematic investigation of the emissivity of strongly interacting matter, HADES has recently measured the dielectron emission in Au+Au collisions at 1.23A GeV beam energy. The first measurement for Au+Au completes the systematics of dilepton production in NN/pA/AA collisions in the SIS18 energy range.
This contribution will present new results for the Au+Au system based on a data sample of 5.0 billion events of the 40% most central collisions.
The Legal Question of Morality Sellheim, Nikolas P
Social & legal studies,
04/2016, Letnik:
25, Številka:
2
Journal Article
Recenzirano
The commercial seal hunt has faced significant opposition through campaigns and public opinion. Based on this opposition, the European Union (EU) adopted a regime in 2009, effectively shutting down ...the EU market for commercial seal products. This ban appears to be based on a European moral standard relating to the welfare of animals, and the EU has successfully defended this claim under the Dispute Settlement Process of the World Trade Organization (WTO). This article critically examines whether such a moral standard exists or whether it is merely an opinion without deeper moral contexts. It further discusses the problems relating to drawing moral conclusions based on ‘public opinion’ and responses to a possible accompanying ‘moral standard’. The article delves into the legal dimension of a ‘European morality’ and discusses in how far moral concerns have been dealt with under the WTO and before EU Courts. It becomes evident that whilst arguing for a European moral standard under the WTO, the EU has shown in European case law that the determination of moral standards rests with the nation states.
This article analyses the EU Seal Regime, which has effectively shut down the EU's internal market for seal products. While seemingly corresponding to the Community's overall animal welfare policies, ...it is argued that instead of following the moral narratives applied in animal welfare legislation, the Regime is instead to be considered a statement of disapproval rather than rooted in moral claims. Applying the focal point theory of expressive law, the article shows that cooperative as well as coordinative actions have taken place between EU policy-makers and anti-sealing NGOs to frame a regime that serves as the Community's voice of disapproval of the seal hunt. While feeding on available knowledge on the genesis of the Seal Regime, this article contributes to the discourse on the Regime's purpose and its function beyond its tangible effects.
We present data on charged kaons (K±) and ϕ mesons in Au(1.23A GeV)+Au collisions. It is the first simultaneous measurement of K− and ϕ mesons in central heavy-ion collisions below a kinetic beam ...energy of 10A GeV. The ϕ/K− multiplicity ratio is found to be surprisingly high with a value of 0.52±0.16 and shows no dependence on the centrality of the collision. Consequently, the different slopes of the K+ and K− transverse-mass spectra can be explained solely by feed-down, which substantially softens the spectra of K− mesons. Hence, in contrast to the commonly adapted argumentation in literature, the different slopes do not necessarily imply diverging freeze-out temperatures of K+ and K− mesons caused by different couplings to baryons.
.
The centrality determination for Au + Au collisions at 1.23
A
GeV, as measured with HADES at the GSI-SIS18, is described. In order to extract collision geometry related quantities, such as the ...average impact parameter or number of participating nucleons, a Glauber Monte Carlo approach is employed. For the application of this model to collisions at this relatively low centre-of-mass energy of
s
NN
=
2
.
42
GeV special investigations were performed. As a result a well defined procedure to determine centrality classes for ongoing analyses of heavy-ion data is established.
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