Analysis of a K -Scattering Phase Shift and Evidence for the  (900) Meson

Recently we have given evidence for the existence of the σ particle. In these previous works, the ππ S-wave phase shift is reanalyzed, by introducing a repulsive background suggested by the chiral symmetry, and by applying the new method of Interfering Breit-Wigner amplitudes. In this work we also s... View More