In-medium Hadrons - Properties, Interaction and Formation

In this talk various aspects of in-medium behavior of hadrons are discussed with an emphasis on observable effects. Examples for theoretical predictions of in-medium spectral functions are given and the importance of resonance-hole excitations is stressed. It is also stressed that final state interactions can have a major effect on observables and thus have to be considered as part of the theory. This is demonstrated with examples from neutrino-nucleus interactions. Finally, the possibility to access hadron formation times in high-energy photonuclear (or neutrino-induced) reactions is illustrated.Comment: Invited talk given by U. Mosel at Vth Conference on Hadronic Physics, ICTP, Trieste, May 200

Partial wave analysis of (

The recent Crystal Ball measurements of the eta-meson photoproduction on the proton are analyzed within an unitary coupled-channel Lagrangian approach. The dip observed in the reaction cross section at 1.68 GeV is explained in terms of the interference between the S11(1535) and S11(1650) states. Additional contributions from the P11 partial wave are also important. No strong indication for the narrow P11 state with a width of 15 MeV is found. Predictions for the double-spin asymmetry Cz are presented and discussed