Narrow Results

One of the experimental programs at the TOF spectrometer located at the COSY-accelerator (Forschungszentrum Jülich, Germany) is the study of ω-meson production in proton proton collisions (pp → ppω). Recently, a measurement was performed with a polarized beam at an excess energy of ∊ = 129 MeV, which offers the possibility to analyze polarization observables of this reaction channel for the first time. The analyzing power (A_y) of the pp → ppω-reaction was determined to be compatible with zero.

The reaction pp → ppω was studied at COSY-TOF for excess energies of ϵ = 93 MeV, 129 MeV, 178 MeV. The continuous change of the angular distribution of the ω meson in the overall CMS away from isotropy shows the increasing contribution of higher partial waves to the production process. This finding is supported by the orientation of the ω-spin (measured via the ω decay plane). For one excess energy ϵ = 129 MeV the analyzing power A_y has been found to be compatible with zero. These results will facilitate a quantitative partial wave analysis of this reaction.