München 2019 – wissenschaftliches Programm
HK 17.3: Hauptvortrag
Dienstag, 19. März 2019, 12:10–12:45, Plenarsaal
Strange hadrons in cold and hot nuclear matter* — •Joana Wirth for the HADES collaboration — Physik Department, TUM, Garching, Germany — Excellence Cluster "Universe", Garching, Germany
The properties of hadrons immersed in a strongly interacting environment have been of great interest in recent decades. HADES explores the effects of nuclear matter in heavy ion collisions where baryon densities ρB exceed the normal nuclear density. However, modifications of hadron properties are already expected in cold nuclear matter (ρ0), which is investigated in hadron-nucleus reactions with HADES where the dynamics are less complex and fundamental aspects can be addressed more directly.
A nearly complete set of strange particles (K±,0, Λ and φ) produced in the Au+Au collisions at 1.23A GeV as well as in π−+A (A=C, W) at pπ−= 1.7 GeV/c has been measured.
We will present results on the (double-differential) yields and compare them with transport calculations. The KN potential is studied by means of the KS0 and Λ kinematical distributions. Special attention will be on the investigation of the exclusive channel π− + p → K0 + Λ to shed light on the Λ N and Σ0 N potentials predicted by χ effective theory. In addition, the relative production yields of φ to K− in all three collision systems will be discussed. Moreover, the K− and φ absorption studied in π A collisions will be addressed in a model-independent way for the first time. ∗ supported by the DFG cluster of excellence "Origin and Structure of the Universe" and SFB 1258