Hadrons in nuclei from high (200 GeV) to low (1 GeV) energies

The study of the interaction of hadrons, produced by introducing elementary probes into a nucleus, with the surrounding nuclear medium can give insight into two important questions. Firstly, at high energies, the production process, the time-scales connected with it, and the prehadronic interactions can be studied by using the nuclear radius as a length-scale. We do this here by analyzing data from the EMC and HERMES experiments on nuclear attenuation. Secondly, at low energies the spectral function, and thus the selfenergy of the produced hadron, can be studied. Specifically, we analyze the CBELSA/TAPS data on ω production in nuclei and discuss the importance of understanding in-medium effects both on the primary production cross section and the final state branching ratio. In both of these studies, an excellent control of the final state interactions is essential.