A study of pi /sup -/ pi /sup -/ scattering from pi /sup -/p interactions at 393 GeV/c

A modified Chew-Low extrapolation procedure is applied to the reaction pi /sup -/p to Delta /sup ++/ pi /sup -/ pi /sup -/ to extract the I=2 pi pi elastic cross sections from threshold to 1260 MeV. The predictions of the one-pion-exchange model are used to estimate the contributions from background processes of the type pi /sup -/p to Delta /sup 0/ rho /sup 0/. The moments of the pi /sup -/ pi /sup -/ angular distribution are also extrapolated to the pion pole and a phase shift analysis performed. The s-wave inelasticity is constrained using information on the inelastic cross section coming from six-body final states. The magnitude of the s-wave phase shift at the K/sup 0/ mass is found to be 7.2 degrees +or-1.0 degrees , increasing to 26.2 degrees +or-2.5 degrees at 1 GeV. d- and g-waves contribute above about 900 MeV, but the corresponding phase shifts are small compared with the s-wave. All three phase shifts have the same sign. (24 refs).