Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

We present strangeness data taken with the High Acceptance Di-Electron Spectrometer (HADES) at the SchwerIonenSynchrotron SIS18 at the GSI Helmholtzzentrum Darmstadt. HADES, primarily designed to measure dielectrons, offers excellent hadron identification capabilities, too. Yields and phase-space distributions have been determined for the collision system Ar+KCl at 1.76A GeV and for strange particle species, with a substantial number of them being produced well below the production threshold in elementary nucleon-nucleon collisions. Here, sub-threshold production of φ mesons appeared to contribute substantially to the K⁻ yield. Confronting the K⁰ _s spectra, measured over a wide range in momentum and rapidity, to predictions of the IQMD transport model points to a repulsive in-medium K⁰ potential of about 40 MeV. Furthermore, we present our results on Λ-p intensity interferometry in Ar+KCl and compare them to other data.