Measurement of double polarisation asymmetries in ω-photoproduction

The first measurements of the beam-target-helicity-asymmetries E and G in the photoproduction of ω-mesons off protons at the CBELSA/TAPS experiment are reported. E (G) was measured using circularly (linearly) polarised photons and a longitudinally polarised target. E   was measured over the photon energy range from close to threshold (Eγ=1108 MeVEγ=1108 MeV) to Eγ=2300 MeVEγ=2300 MeV and G   at a single energy interval of 1108