Measurement of polarisation observables in Ks0Σ+ photoproduction off the proton

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

Experimental constraints on the ω –nucleus real potential

In a search for ω mesic states, the production of ω -mesons in coincidence with forward going protons has been studied in photon induced reactions on 12 C for incident photon energies of 1250–3100 MeV. The π0γ pairs from decays of bound or quasi-free ω -mesons have been measured with the CBELSA/TAPS detector system in coincidence with protons registered in the MiniTAPS forward array. Structures in the total energy distribution of the π0γ pairs, which would indicate the population and decay of bound ω 11 B states, are not observed. The π0γ cross section of 0.3 nb MeV −1  sr −1 observed in the bound state energy regime between −100 and 0 MeV may be accounted for by yield leaking into the bound state regime because of the large in-medium width of the ω -meson. A comparison of the measured total energy distribution with calculations suggests the real part V0 of the ω 11 B potential to be small and only weakly attractive with V0(ρ=ρ0)=−15±35(stat)±20(syst) MeV in contrast to some theoretical predictions of attractive potentials with a depth of 100–150 MeV

"Table 20" of "Linearly polarised photon beams at ELSA and measurement of the beam asymmetry in pi^0-photoproduction off the proton"

Beam asymmetry as a function of the PI0 centre of mass scattering angle

"Table 9" of "Linearly polarised photon beams at ELSA and measurement of the beam asymmetry in pi^0-photoproduction off the proton"

Beam asymmetry as a function of the PI0 centre of mass scattering angle

"Table 16" of "Linearly polarised photon beams at ELSA and measurement of the beam asymmetry in pi^0-photoproduction off the proton"

Beam asymmetry as a function of the PI0 centre of mass scattering angle

"Table 7" of "Linearly polarised photon beams at ELSA and measurement of the beam asymmetry in pi^0-photoproduction off the proton"

Beam asymmetry as a function of the PI0 centre of mass scattering angle

"Table 19" of "Linearly polarised photon beams at ELSA and measurement of the beam asymmetry in pi^0-photoproduction off the proton"

Beam asymmetry as a function of the PI0 centre of mass scattering angle

"Table 6" of "Linearly polarised photon beams at ELSA and measurement of the beam asymmetry in pi^0-photoproduction off the proton"

Beam asymmetry as a function of the PI0 centre of mass scattering angle

"Table 2" of "Linearly polarised photon beams at ELSA and measurement of the beam asymmetry in pi^0-photoproduction off the proton"

Beam asymmetry as a function of the PI0 centre of mass scattering angle

"Table 4" of "Linearly polarised photon beams at ELSA and measurement of the beam asymmetry in pi^0-photoproduction off the proton"

Beam asymmetry as a function of the PI0 centre of mass scattering angle