Hadronic interaction of the eta meson with two nucleons

Moskal, P.; Adam, H. -H.; Budzanowski, A.; Czyzykiewicz, R.; Grzonka, D.; Janusz, M.; Jarczyk, L.; Kamys, B.; Khoukaz, A.; Kilian, K.; Klaja, P.; Majewski, J.; Oelert, W.; Piskor-Ignatowicz, C.; Przerwa, J.; Rozek, T.; Sefzick, T.; Siemaszko, M.; Smyrski, J.; Taschner, A.; Winter, P.; Wolke, M.; Wustner, P.; Zipper, W.

Hadronic interaction of the eta meson with two nucleons

Authors

Description

The COSY-11 collaboration has conducted experiments aiming at the determination of the excitation function and phase-space population of the p p --> p p eta reaction close to the kinematical threshold. The precise data obtained with the stochastically cooled proton beam of the cooler synchrotron COSY and the high resolution zero-degree magnetic spectrometer allowed for the observation of the significant deviations - in the shape of the excitation function and two-particle invariant masses - from the predictions based on the assumption that the reaction phase space is homogenously populated. Comparison of the shape of the excitation function for the p p --> p p eta and p p --> p p eta-prime reaction allows to distinquish in the model independent way an influence originating from the proton-proton and proton-eta interaction. For the comparison the full data set from experiments performed at COSY and other laboratories is used.
Talk given at 10th International Symposium on Meson-Nucleon Physics and the Structure of the Nucleon (MENU 2004), Beijing, China, 29 Aug - 4 Sep 2004, 4 pages, 1 figure, to be published in Int. J. Mod. Phys