Mainz 2012 – wissenschaftliches Programm

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HK: Fachverband Physik der Hadronen und Kerne

HK 10: Struktur und Dynamik von Kernen

HK 10.8: Vortrag

Montag, 19. März 2012, 18:45–19:00, RW 3

Constraining the in-medium hyperon-nucleon interactionin heavy-ion collisions — •Theodoros Gaitanos, Anika Obermann, and Horst Lenske — Institut für Theoretische Physik, Universität Giessen, Germany

The knowledge of the strangeness sector of strong interactions is important for our understanding of hadron dynamics. It is still a widely debated topic how the hyperon-nucleon interaction is modified inside a dense hadronic environment. From our recent in-medium T-matrix calculations for hyperon-nucleon scattering with strangeness exchange, e.g., Σ⁺n→ Σ⁰p,Λ p, we determine the in-medium modifications of cross sections at finite baryon density. The results are used in intermediate energy heavy-ion collisions, which offer an unique opportunity to investigate this issue in the laboratory. Indeed, precise data on K^0,+ and Λ+Σ⁰ production exist and can help us to study the in-medium modifications of the hyperon-nucleon interaction with strangeness exchange. We apply a relativistic Boltzmann-like transport approach, which incorporates a perturbative propagation of particles with finite strangeness (positive and neutral kaons with S=1 and hyperons with S=−1) under the influence of chiral potentials for the kaons and hyperons self-energies. Our calculations shows that strangeness production in heavy-ion collisions is a sensitive tool for investigations of in-medium YN- and YY-interactions. We compare transport theoretical results on strangeness yields and their rapidity distributions with data and discuss in particular the high density properties of YN-interactions, entering e.g. also into neutron star calculations.