The pi pi scattering amplitude and the Sigma pole

0458162 - ÚJF 2016 RIV PL eng C - Konferenční příspěvek (zahraniční konf.)
Bydžovský, Petr - Kaminski, R. - Nazari, V.
The pi pi scattering amplitude and the Sigma pole.
Acta Physica Polonica B - Proceedings Supplement. Vol. 8. Krakow: Jagellonian University, 2015, s. 377-382. ISSN 1899-2358.
[Excited QCD 2015. Tatranská Lomnica (SK), 08.03.2015-14.03.2015]
Grant CEP: GA ČR(CZ) GA15-04301S
Institucionální podpora: RVO:61389005
Klíčová slova: pion-pion scattering * coupled channel * amplitudes
Kód oboru RIV: BE - Teoretická fyzika

The multichannel amplitudes used in the analysis of the pi pi-scattering data and in the description of final-state interaction effects in heavy-meson decays predict too broad and heavy Sigma meson (f0(500) resonance) which is in disagreement with results from other, especially recent, analyses. The amplitudes are constructed using a uniformizing variable and proper analytical continuation of the S-matrix elements but the crossing symmetry constraint, important in the S-wave, is not included. We modified, therefore, the amplitudes using the dispersion relations with imposed crossing symmetry (GKPY equations). We also examined the multichannel formalism comparing the single- and two-channel analyses of the pi pi-scattering data. After the modification and in the single-channel analysis, the Sigma pole acquired values within the limits accepted in the Particle Data Tables.
Trvalý link: http://hdl.handle.net/11104/0258447