Photoproduction of ω-Mesons at ELSA and the role of azimuthal asymmetries

摘要

Measurements of ω photoproduction of the Crystal-Barrel/TAPS experiment at the ELSA accel-erator of Bonn University are presented which used linearly polarized tagged photon beam from threshold to E_γ=1700 MeV. The azimuthal asymmetries Σ and Σ_π indicate s-channel resonance contributions on top of the established t-channel exchange processes. These findings are further enhanced by a very first measurement of the G-asymmetry which, in addition to the polarized photon beam, also requires a longitudinally polar-ized proton target. An intuitive interpretation of the specific sensitivity of the azimuthal asymmetries to the reaction mechanisms involved is given.