STUDY OF THE PRODUCTION MECHANISM OF THE η MESON BY MEANS OF ANALYSING POWER MEASUREMENTS

Information about the production mechanism of the η meson in proton-proton collisions can be inferred by confronting the experimental studies on the analysing power for the $\vec{p}p\to pp\eta$ reaction with the theoretical predictions of this observable. The determined analysing powers for Q=10 MeV and Q=36 MeV are consistent with zero. Results show that the predictions of pure pseudoscalar meson exchange model fairly describe the experimental data, while the predictions of pure vector meson exchange dominance model disagree with the data at the level of 4.3 σ.