Exclusive measurement of pp -> pp pi(+)pi(-) at CELSIUS

With the PROMICE/WASA detector setup at CELSIUS the reaction pp --> NN pi p i has been measured in the energy range from 650 to 775 MeV. These data con stitute the first exclusive high-statistics measurements on a pure hydrogen target, supplying both differential and integral cross sections. Most of t he differential spectra for pp --> pp pi (-)pi (+) are close to phase space predictions (including NN final-state interaction) identifying the product ion via N*(1440) --> N(pi pi)(1=L=0) as the dominant process. However, the measured Mpi+pi--spectrum is strikingly different from phase space simulati on pointing to the importance of other processes in this reaction. Possible contributions from dibaryon resonances are discussed.