CCAST, World Lab, Beijing 100080, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
Article; Proceedings Paper
We study coupled channel effects upon isospin I = 2 and I = 0 ππ S-wave interaction. With introduction of the ππ &RARR; ρρ &RARR; ππ coupled channel box diagram contribution into ππ amplitude in addition to ρ and f(2)(1270) exchange, we reproduce the ππ I=2 S-wave and D-wave scattering phase shifts and inelasticities up to 2 GeV quite well in a K-matrix formalism. For I = 0 case, the same ππ &RARR; ρρ &RARR; ππ box diagram is found to give the largest contribution for the inelasticity among all possible coupled channels including ππ &RARR; ωω &RARR; ππ, ππ &RARR; KK &RARR; ππ. We also show why the broad a appears narrower in production processes than in ππ scattering process.