Beam Asymmetries in π0 Photoproduction on the Proton

Polarization observables, such as the beam asymmetry Σ, are vital to the study of the many N* and Δ resonances that decay to the pπ0 final state. Beam asymmetries in π0 photoproduction off the proton have been determined using the Crystal Barrel CsI(Tl) calorimeter at ELSA, University of Bonn in Germany, in the energy range Eγ = 920 to 1680 MeV by analyzing the neutral decay mode π0→γγ. In this experiment, the BaF2 spectrometer TAPS was placed in the forward direction increasing the solid angle coverage to nearly 4π and serving as a fast trigger. For the first time, these measurements include the most forward angles in θπ0c·m. Additionally, this analysis provides new data points in the energy range Eγ = 1510 to 1680 MeV where few measurements have previously been made.