Threshold measurements at the experiment COSY - 11

COSY-11 is an internal target experiment presently being installed at the cooler ring COSY-Juelich, using a cluster target in front of one of the C-type dipole magnet. The magnetic field separates and momentum analyses reaction products from the circulating beam. It is proposed to scan relevant momentum regions via the pp→ppX reaction and to observe the structure of resonances by missing mass determination. A detection of decay particles from particular resonances (e.g. f0(975)) should support its identification and enable to determine its internal structure. The vanishing relative momenta between the reaction products make threshold studies an ideal tool to investigate meson-meson, meson-baryon, and nucleon-baryon final state interactions. The special emphasis of the COSY-11 experiment is the observation of narrow resonances especially in the 1 GeV/c2 mass range where flavour strangeness becomes important. (orig.)