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arXiv · hep-ph/0310082

Roy's equations and the pion-pion experimental data

R. Kaminski·L. Lesniak·B. Loiseau
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Abstract

Roy's equations are used to check if the scalar-isoscalar pion-pion scattering amplitudes fitted to experimental data fulfill crossing symmetry conditions. It is shown that the amplitudes describing the ``down-flat'' phase shift solution satisfy crossing symmetry below 1 GeV while the amplitudes fitted to the "up-flat'' data do not. In this way the long standing "up-down" ambiguity in the phenomenological determination of the scalar-isoscalar pion-pion amplitudes has been resolved confirming the independent result of the recent joint analysis of the pi+pi- and pi0pi0 data.

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R. Kaminski, L. Lesniak, B. Loiseau. 2003-10-07. Roy's equations and the pion-pion experimental data. https://doi.org/10.1063/1.1799704

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