Measurement of the eta production in proton proton collisions with the COSY time-of-flight spectrometer.

The reaction {pp \rightarrow pp \eta} was measured at excess energies of 15 and 50 MeV at an external beam-line of COSY with the Time of Flight Spectrometer. During one week of beam-time about 5000 events were measured for each excess energy. Both reaction protons of the process pp\protect \relax \kern .16667em \eta are detected with an acceptance of nearly 100% and the \eta is reconstructed by the missing mass technique. In a first step one third of the 15 MeV excess energy events are evaluated and examined with respect to differential values of which preliminary distributions are presented.