ω
photoproduction off hydrogen and deuterium has been studied with the tagged photon beam of the ELSA accelerator in Bonn for photon energies up to 2.0 GeV. The
ω
meson has been identified via the
ω
...→ π
0
γ
→
γγγ
decay mode, using the combined setup of the Crystal Barrel/TAPS detector systems. Both inclusive and exclusive analyses have been carried out. Differential and total cross-sections have been derived for
ω
mesons produced off free protons and off protons and neutrons bound in deuterium. The cross-section for the production off the bound neutron is found to be a factor of ≈ 1.3 larger than the one off the bound proton in the incident beam energy region 1.2 GeV <
E
γ
< 1.6 GeV. For higher incident beam energies this factor goes down to ≈ 1.1 at 2.0 GeV. The cross-sections of this work have been used as normalization for transparency ratio measurements.
The reaction γp→KS0Σ+ is studied in the photon energy range from threshold. Linearly polarised photon beams from coherent bremsstrahlung enabled the first measurement of photon beam asymmetries in ...this reaction up to Eγ=1650MeV. In addition, the recoil hyperon polarisation was determined through the asymmetry in the weak decay Σ+→pπ0 up to Eγ=2250MeV. The data are compared to partial wave analyses, and the possible impact on the interpretation of a recently observed prominent structure in the cross section near the K⁎ thresholds is discussed.
Data on the polarization observables T, P, and H for the reaction γp→pπ0 are reported. Compared to earlier data from other experiments, our data are more precise and extend the covered range in ...energy and angle substantially. The results were extracted from azimuthal asymmetries measured using a transversely polarized target and linearly polarized photons. The data were taken at the Bonn electron stretcher accelerator ELSA with the CBELSA/TAPS detector. Within the Bonn-Gatchina partial wave analysis, the new polarization data lead to a significant narrowing of the error band for the multipoles for neutral-pion photoproduction.
A measurement of the double-polarization observable
for the reaction
is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol ...(C
H
OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from
to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.
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