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Re-analysis of ππ/ KπPhase Shift and Existence of σ$(600) / κ(900)-Particle

Taku Ishida·Muneyuki Ishida·Shin Ishida·Kunio Takamatsu·Tsuneaki Tsuru
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Abstract

Re-analyzing the old phase shift data of I=0, ππ(I=1/2, Kπ) scattering, we show an evidence for existence of the σ-particle (κ-particle) with a comparatively light mass, which has been missing for a long time: In the analysis we have applied a new method of interfering Breit-Wigner amplitudes, which makes the scattering amplitude parametrized in terms of only physical quantities, mass and width of resonant particles, in conformity with unitarity. We have introduced phenomenologically a background phase shift δ_{BG} of repulsive core type. The χ^2-fits of the both ππ- and Kπ- phase shifts are improved greatly with the δ_{BG} over the conventional fits without it.

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Taku Ishida, Muneyuki Ishida, Shin Ishida, Kunio Takamatsu, Tsuneaki Tsuru. 1997-12-02. Re-analysis of ππ/ KπPhase Shift and Existence of σ$(600) / κ(900)-Particle. https://doi.org/10.1063/1.55961

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