München 2019 – wissenschaftliches Programm
HK 54.15: Poster
Donnerstag, 21. März 2019, 16:30–19:00, Foyer Theresanium
In-medium properties of Λ in π−-induced reactions at 1.7 GeV/c — •Steffen Maurus for the HADES collaboration — Physik Department, TUM, Garching, Germany — Excellence Cluster "Universe", Garching, Germany
The existence of a two solar mass neutron star, gives strong boundaries to the equation of state (EOS) and models describing such dense objects. While more experiments offer data which reduce the allowed phase space, the appearance of hyperons in the nucleus of the neutron star is still a discussed topic. For all these EOS, the hyperon-nucleon interaction plays a crucial role. Of particular interest is the Λ hyperon, which should appear first because it is the lightest hyperon. In 2014, the HADES collaboration measured π− + A ( A = C, W) reactions at an incident secondary pion beam momentum of 1.7 GeV/c. Since the pion-nucleon cross section is rather sizeable, hyperon production takes place at the surface of the nucleus. This is an ideal system, since the path length of the produced hyperons through the nuclear matter is quite large. In our experimental approach we choose the exclusive channel of π−+p → Λ + K0, in both nuclear environment. Using the GiBUU-transport code, we can test different scenarios involving different couplings of Λ with the normal nuclear environment in combination with K0. One of these scenarios also includes for the first time a repulsive Σ0 potential, predicted by the χ effective theory. We will report on the ongoing analysis and demonstrate our sensitivity to the different scenarios of the in-medium propagation.
Supported by the Excellence Cluster "Universe" and SFB 1258