Measurement of strange baryon resonances in heavy ion collisions

In-medium modifications of the production and propagation of strange particles in hot and dense nuclear matter is one of the main topics in relativistic heavy-ion collisions. At SIS energies, complex mechanisms like strangeness exchange reaction (π+Y↔K-+B) complicate the interpretation of existing data, e.g. recent theoretical calculations predict an important coupling of the K- with the Σ(1385) in the medium. Therefore a systematic study of strange baryon resonances is needed to achieve a better understanding of strangeness production close to threshold. The FOPI detector at the SIS accelerator of GSI-Darmstadt allows to measure and reconstruct a large variety of strange particles. Different excited states of strange baryon resonances like Σ(1385), K(892), H-dibaryons and hypertritons have decay channels that allow their detection in large statistics data samples. The evidence for the resonances in the Ni+Ni and Al+Al systems at 1.9 AGeV will be presented. (orig.)