[en] Models for extracting the nucleon resonance parameters from the data of meson-baryon reactions are reviewed. The development of a dynamical coupled-channel model with nnN unitarity is briefly reported

[en] The author reports on several extensions of the Bonn meson exchange model for the NN interaction, first, to the region above pion threshold; second, to systems involving strange particles. 13 refs.; 9 figs

[en] The properties of a relativistic meson-baryon P-wave amplitude subject to a single attractive driving pole are given, and various stability effects are studied

[en] A method to identify hadronic molecules in the particle spectrum is reviewed and the conditions for its applicability discussed. Special emphasis is put on the discussion of molecule candidates in the baryon spectrum. (orig.)

[en] The neutron star parameters in the model extended by the inclusion of δ meson and additional nonlinear vector meson interactions are studied

[en] We discuss some of the most relevant non-standard quark configurations in hadron spectroscopy, which are alternative to the qqq and qq¯ description of baryons and mesons, respectively. They include the quark-diquark and four-quark (five-quark) meson-meson (meson-baryon) bound states. To this purpose, we briefly review the diquark model of baryons and tetraquark states and the hadro-quarkonium model of heavy-light tetra- and pentaquarks. Some applications of the previous models are discussed. (author)

[en] In 1989 Prof H. Narnhofer and Prof. W. Thirring established a (nonlocal) model of fermions with pair interactions. The existence of equilibrium states and the appearance of mixing properties was proofed. If this model reflects the basic facts of nature, one has to expect and to require that at high temperatures there is a unique equilibrium state and at low temperatures there are many different equilibrium states. Uniqueness of the equilibrium state at high temperatures is the topic of this dissertation. One may be astonished, that the proof of the uniqueness requires such a huge machinery, while the existence of KMS-states followes from fairly general conditions. Two states differ, if they can be distinguished by experiment. If one considers now that we have to show that two KMS-states at high temperatures result into the same value in all experiments one can think of, one might get an idea how unhandy this problem is. Even a conscious numeration of all experiments was a problem. Surprisingly only a few principal ideas of the treatment of spin-models survive. The temperature is the leading parameter and therefore it is a good idea to make a high temperature perturbation expansion for the KMS-condition, which fixes an equilibrium state in mathematical terms. But when we choose a generating vector for the perturbation expansion the similarities end. We better use physical considerations: at high temperatures we expect that chemical bounds will be broken up and the interacting equilibrium state will differ only slightly from the equilibrium state for the free time evolution. Roughly spoken, one can expect that high-energetic particles neglect interactions and fly in a straight line. In chapter 2.4 the whole machinery is presented in an easy-to-survey manner on a simple interaction. But in the case of pair interactions every particle interacts with each other and so the author was not able to find an easily accessible form of the developed method for this case. Starting from bounded local interactions we release the spatial limit and prove the uniqueness of the KMS-state (with a momentum cutoff). (author)

[en] The authors question the viability of the proposed interpretation I = 0, 1/2, and 1 pseudoscalar-pseudoscalar scattering data given in Ref.[1] since t-channel forces have been ignored in apparent conflict with the data in the closely related exotic I = 3/2 and 2 channels

No abstract available

[en] We review the dynamical model for meson-meson scattering developed by our group. This model is based on the meson-exchange picture and reproduces quantitatively the ππ and Kπ phase shifts. These results can be used for the calculation of the pion electromagnetic form factor as well as the scalar factor of the pion. We also discuss our recent calculation of the nucleon sigma term within the same model. (authors)