T. Galatyuk

Dielectron production in Ar+KCl collisions at 1.76A GeV

We present results on dielectron production in 40 Ar+KCl collisions at 1.76A GeV. For the first time ω mesons could be reconstructed in a heavy-ion reaction at a bombarding energy which is well below the production threshold in free nucleon-nucleon collisions. The ω multiplicity has been extracted and compared to the yields of other particles, in particular of the φ meson. At intermediate e + e invariant masses, we find a strong enhancement of the pair yield over a reference spectrum from elementary nucleon-nucleon reactions suggesting the onset of non-trivial effects of the nuclear medium. Transverse-mass spectra and angular distributions have been reconstructed in three invariant mass bins. In the former unexpectedly large slopes are found for high-mass pairs. The latter, in particular the helicity-angle distributions, are largely consistent with expectations for ]

Medium effects in proton-induced

We present the analysis of the inclusive K 0 production in p + p and p + Nb collisions measured with the HADES detector (GSI Helmholtzzentrum for Heavy-Ion Research, Darmstadt) at a beam kinetic energy of 3.5 GeV. Data are compared to the Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) transport model. The data suggest the presence of a repulsive momentum-dependent kaon potential as predicted by the chiral perturbation theory (ChPT). For the kaon at rest and at normal nuclear density, the ChPT potential amounts to ≈ 35 MeV. A detailed tuning of the kaon production cross sections implemented in the model has been carried out to reproduce the experimental data measured in p + p collisions. The uncertainties in the parameters of the model were examined with respect to the sensitivity of the experimental results from p + Nb collisions to the in-medium kaon potential.

K^{0}

An exclusive analysis of the 4-body final states

production at 3.5 GeV

mathrm{Lambda + p + pi^{+} + K^{0}}

Associate K^0 production in p+p collisions at 3.5 GeV: The role of Delta(1232)++

and

Hades experiments: investigation of hadron in-medium properties

mathrm{Sigma^{0} + p + pi^{+} + K^{0}}

DILEPTON PRODUCTION STUDIED WITH THE HADES SPECTROMETER

measured with HADES for p+p collisions at a beam kinetic energy of 3.5 GeV is presented. The analysis uses various phase space variables, such as missing mass and invariant mass distributions, in the four particle event selection (p,

K^{*}(892)^{+} production in proton-proton collisions at E_{beam}=3.5 GeV

pi^+

Proton induced dielectron radiation off Nb: Pt and Y distributions

,

Di-pion and di-electron production in NN reactions with HADES at 1.25GeV incident beam energy..

pi^+