ππ phase shift analysis

We perform an energy independent ππ phase shift analysis in the energy range 440 < Mππ < < 1400 MeV using high statistics π−p⇒π−π+n data at 17.2 GeV/c. The method is based on an amplitude analysis of the production process and the extrapolation of the dominant π exchange amplitudes to the π exchange pole. We consider the phase shift ambiguities and study ways of selecting the physical solution. We determine the parameters of the ρ and f resonances. We find an I = 0 S wave resonance under the f and we comment on the properties of the S* resonance near the KK threshold.