PI-PI SCATTERING-AMPLITUDES WITHIN THE SUBTHRESHOLD TRIANGLE

The on-shell pi pi scattering amplitudes within and on the boundary of the subthreshold triangle (0 less than or equal to s less than or equ al to Sigma, 0 less than or equal to t less than or equal to Sigma, 0 less than or equal to u less than or equal to Sigma = 4 mu(2)) are inv estigated. Interior Dispersion Relations, when combined with experimen tal pi pi phase shifts, inelasticities, and scattering lengths, provid e an almost perfect tool for this study. The general results obtained are in striking agreement with the chiral model of Weinberg.