High resolution study of thep final state interaction in the reaction p + p ! K + + (p)

The reaction pp ! K + + (�p) was measured at Tp = 1.953 GeV and � = 0 ◦ with a high missing mass resolution in order to study thep final state interaction. The large final state enhancement near thep threshold can be described using the stan- dard Jost-function approach. The singlet and triplet scattering lengths and effective ranges are deduced by fitting simultaneously thep invariant mass spectrum and the total cross section data of the freep scattering.