Exotic Nuclei and Matter in a Chirally Effective Approach

A relativistic approach to describe nuclear and in general strongly interacting matter is introduced and discussed. Here, not only the nuclear forces but also the masses of the nucleons are generated through meson fields. Within this framework it is possible to calculate properties of finite nuclei at a level of accuracy similar to dedicated relativistic nuclear structure models. Due to the more general approach, a wider range of properties of hadronic states can be investigated. A number of results for heavy and neutron-rich nuclei toward the drip line are presented.Comment: Contribution to the Proceedings of the VII International Symposium on EXOtic Nuclei (EXON-2014) in St. Petersburg, Russi

Parity Doublet Model applied to Neutron Stars

The Parity doublet model containing the SU(2) multiplets including the baryons identified as the chiral partners of the nucleons is applied for neutron star matter. The chiral restoration is analyzed and the maximum mass of the star is calculated.Comment: Proceeding to the conference International Symposium on Exotic States of Nuclear Matte

Modelling Hybrid Stars in Quark-Hadron Approaches

The density in the core of neutron stars can reach values of about 5 to 10 times nuclear matter saturation density. It is, therefore, a natural assumption that hadrons may have dissolved into quarks under such conditions, forming a hybrid star. This star will have an outer region of hadronic matter and a core of quark matter or even a mixed state of hadrons and quarks. In order to investigate such phases, we discuss different model approaches that can be used in the study of compact stars as well as being applicable to a wider range of temperatures and densities. One major model ingredient, the role of quark interactions in the stability of massive hybrid stars is discussed. In this context, possible conflicts with lattice QCD simulations are investigated.Comment: Contribution to the EPJA Topical Issue on "Exotic Matter in Neutron Stars

Modeling Hybrid Stars

We study the so called hybrid stars, which are hadronic stars that contain a core of deconfined quarks. For this purpose, we make use of an extended version of the SU(3) chiral model. Within this approach, the degrees of freedom change naturally from hadrons (baryon octet) to quarks (u, d, s) as the temperature and/or density increases. At zero temperature we are still able to reproduce massive stars, even with the inclusion of hyperons.Comment: To appear in the proceedings of Conference C12-08-0