Further Study of the ππ S-Wave Isoscalar Amplitude Below the K(anti)K Threshold

We continue the analysis of S-wave production amplitudes for the reaction π-p→ π+π- involving the data obtained by the CERN-Cracow-Munich collaboration on a transversely polarized target at 17.2 GeV/c π- momentum. This study deals with the region below the K(anti)K threshold. In particular, we study the ''up-steep'' solution containing a narrow S-wave resonance under the ρ(770). This solution exhibits a considerable inelasticity η which does not have any physical interpretation. Assuming that this inelasticity behaviour represents an unlikely fluctuation we impose η≡1 for all data points. This leads to non-physical results in one third of the π+π- effective mass bins and in the remaining mass bins some parameters behave in a queer way. The situation is even worse for the ''down-steep'' solution. We conclude that the 17.2 GeV data cannot be described by a relatively narrow f0(750). The ''down-flat'' and ''up-flat'' solutions which easily pass the η≡1 constraint exhibit a slow increase of phase shifts in the ρ(770) mass range. (author)