Photoproduction of Mesons from Quasifree Nucleons

Recent results for photoproduction reactions of quasi-free nucleons are discussed mainly in view of the electromagnetic excitations of the neutron which cannot be studied in other ways. Such experiments are necessary in order to study the isospin degree of freedom in electromagnetic nucleon resonance excitations. In particular, experiments with the Crystal Ball/TAPS setup at the Mainz MAMI accelerator and the Crystal Barrel/TAPS setup at the Bonn ELSA accelerator are discussed. Both experiments use electromagnetic calorimeters which cover almost the full solid angle and can detect and identify photons from the decay of neutral mesons, recoil protons and neutrons and partly also charged pions. The complications from the Fermi motion of the bound nucleons and final-state interactions of the final-state particles will be discussed. Examples for the impact of the new data comprising absolute cross sections and polarization observables for single- and multiple-meson production reactions are given.