Polarization ObservablesTandFin singleπ⁰- andη-Photoproduction off quasi-free Nucleons

Abstract

Abstract. Meson photoproduction has developed into a powerful tool to study the nucleon excitation spectrum and test effective quark models which operate in the nonperturbative regime of QCD. An insight into the J P configurations and isospin decompositions of the contributing resonances is gained by measuring a minimal set of polarization observables on both the proton and the neutron. Single π 0 -and η-photoproduction off a transversally polarized d-butanol target has been measured with circularly polarized bremsstrahlung photons generated by the MAMI-C electron microtron. With the nearly 4π acceptance of the combined Crystal Ball/TAPS setup the double polarization observable F and the target asymmetry T can be extracted for the first time for polarized, quasi-free neutrons over a wide energy and angular range.