Improvement of ππ amplitudes and correct position of the σ pole

Meson-meson interaction amplitudes especially ππ scattering amplitudes are often used incorrectly. It also applies to parameters of the σ meson. These causes two significant problems: threshold behavior and position of the σ pole which is suspicious. We modified multichannel S- and P- wave amplitude...

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Bibliographic Details
Published inEPJ Web of conferences Vol. 81; p. 5022
Main Authors Nazari, V., Bydžovský, Petr, Kamiński, Robert
Format Journal Article
LanguageEnglish
Published EDP Sciences 2014
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Summary:Meson-meson interaction amplitudes especially ππ scattering amplitudes are often used incorrectly. It also applies to parameters of the σ meson. These causes two significant problems: threshold behavior and position of the σ pole which is suspicious. We modified multichannel S- and P- wave amplitudes for the ππ scattering, using dispersion relations with imposed crossing symmetry condition. The amplitudes are modified in the low-energy region to improve their consistency with experimental data and the dispersion relations. Agreement with data is achieved for both amplitudes from the threshold up to 1800 MeV and with dispersion relations up to 1100 MeV. Consequences of the applied modifications, e.g. changes of the S-wave lowest-pole positions, are presented.
ISSN:2100-014X
2100-014X
DOI:10.1051/epjconf/20148105022