Overview of the electromagnetic production of strange mesons at MAMI

The Mainz Microtron MAMI provides a continuous-wave unpolarized or spin-polarized electron beam with energies up to 1.6 GeV and high degrees of polarization. Electro-production of strange mesons is performed in the multi-spectrometer facility with the Kaos spectrometer for kaon detection and a high-resolution spectrometer for electron detection in plane or out of plane. Differential cross section measurements of exclusive image reactions at low four-momentum transfers in the nucleonʼs third resonance region have been done, followed by a measurement of the beam helicity asymmetry for image. These studies are important for the understanding of the effective coupling of photons to the hadrons and their resonances and electromagnetic form factors entering different effective Lagrangian models for photo- and electro-production of strangeness. The polarized structure function, extracted from the beam helicity asymmetry, shows an especially high sensitivity to model parameters.