Two-Pion Production in Proton-Proton Collisions

• Main Authors: Bashkanov, M, Abdel-Samad, S, Brinkmann, K-Th, Calen, H, Cappellaro, F, Clement, H, Demiroers, L, Doroshkevich, E, Dshemuchadse, S, Ekstrom, C, Erhardt, A, Eyrich, W, Fransson, K, Freiesleben, H, Fritsch, M, Gillitzer, A, Gustafsson, L, Hoistad, B, Jacewicz, M
• Format: Conference Proceeding
• Language: English
• ISSN: 0094-243X
• DOI: 10.1063/1.1799710

Physikalisches Institut, Universitat Tubingen, D-72076 Tubingen (CELSIUS-WASA Collaboration)(COSY-TOF Collaboration) A program to measure the two-pion production in nucleon-nucleon collisions exclusively and in all channels from threshold up to Tp = 1360 MeV has been started at CELSIUS-WASA. First preliminary results for pp+- and pp00 channels are presented. In the near-threshold region they are consistent with a dominance of the Roper excitation and its successive decay into N and channels. At energies Tp > 1 GeV we observe a very different behavior, which is at variance with theoretical predictions. At COSY-TOF exclusive measurements of the pp - > pp+- reaction have been carried out with polarized beam. Preliminary results show non-zero analyzing powers which point to a sizeable admixture of l 0 partial waves indicating possibly an influence of the -channel.