We present the system size (centrality) dependence of the mean transverse mass, of the K/π ratio, and the width of the rapidity distributions. Except for the latter a steep increase with centrality ...is observed for small systems followed by a weak rise or even saturation for higher centralities at both energies. This behavior is compared to calculations using transport models (UrQMD and HSD), a percolation model and the core-corona approach.
Differential production cross sections of K+/- mesons have been measured in p + C and p + Au collisions at 1.6, 2.5, and 3.5 GeV proton beam energy. At beam energies close to the production ...threshold, the K- multiplicity is strongly enhanced with respect to proton-proton collisions. According to microscopic transport calculations, this enhancement is caused by two effects: the strangeness exchange reaction NY --> K- NN and an attractive in-medium K- N potential at saturation density.
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In this contribution we shall discuss some aspects of the role of elementary reference data for the interpretation of the results from nuclear collisions and show in particular that neutron-proton ...interactions play a significant role. Furthermore we point out that a complete set of elementary data is desirable, because most theoretical concepts for the interpretation of nuclear collisions rely on such data as input for their calculations.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Differential production cross sections of K- and K+ mesons have been measured in Ni+Ni and Au+Au collisions at a beam energy of 1.5 A GeV. The K(-)/K(+) ratio is found to be nearly constant as a ...function of the collision centrality and system size. The spectral slopes and the polar emission pattern differ for K- and K+ mesons. These observations indicate that K+ mesons decouple earlier from the fireball than K- mesons.
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The production of pions and kaons has been measured in 197Au+197Au collisions at beam energies from 0.6 to 1.5A GeV with the kaon spectrometer at SIS/GSI. The K+ meson multiplicity per nucleon is ...enhanced in Au+Au collisions by factors up to 6 relative to C+C reactions, whereas the corresponding pion ratio is reduced. The ratio of the K+ meson excitation functions for Au+Au and C+C collisions increases with decreasing beam energy. This behavior is expected for a soft nuclear equation-of-state.
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Charged particle detection in organic semiconductors Beckerle, P; Ströbele, H
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2000, Volume:
449, Issue:
1
Journal Article
Peer reviewed
Polyacetylene is an organic semiconductor in which charges can be set free by a traversing charged particle, transported by an electric field to read-out electrodes and, subsequently, amplified and ...recorded in a way similar to what happens in a silicon-drift detector. In an experimental investigation of the features of this charge transport in thin foils we find drift velocities of the order of 40 cm/s. Stretching of the foils by a factor of three to four increases the drift velocity by a factor of ten and introduces a strong directionality of the charge transport. The detection efficiency of 5 MeV α particles in a few micron thin stretched foil is around 70%.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK