Low-Q: Proton electric and magnetic form factors: The Mainz high-precision proton form-factor measurement

An extensive measurement of the elastic H(e,e')p reaction in the Q²-region from 0.003 to 1 (GeV/c)² has been performed with the three-spectrometer set-up of the A1 collaboration at the Mainz Microtron. The data set consists of about 3,000 overlapping cross-section measurements with a high level of internal redundancy, which allow for a determination of the electric and magnetic form factors with strict control over statistical and systematic errors, in particular also of the charge and magnetization radii of the proton. Besides the classical Rosenbluth separation, the form factors are separated by direct, global fits of different sufficiently flexible models.