Effect of coupled channels of the multi-channel pion-pion scattering in two-pion transitions of the Υ mesons

• Published in: International Journal of Modern Physics: Conference Series 2015, Vol.39, p.1560090
• Main Authors: Surovtsev, Yurii S., Bydžovský, Petr, Gutsche, Thomas, Kamiński, Robert, Lyubovitskij, Valery E., Nagy, Miroslav
• Format: Article
• Language: English
• Subjects: Data analysis; Decay; Mass spectra; Mesons; Scattering
• ISSN: 2010-1945; 2010-1945
• DOI: 10.1142/S2010194515600903

The effect of isoscalar S-wave processes π π → π π , K K ¯ , η η is considered in the analysis of data (from the ARGUS, CLEO, CUSB, Crystal Ball, Belle, BABAR collaborations) on the bottomonia decays — Υ ( m S ) → Υ ( n S ) π π ( m > n , m = 2 , 3 , 4 , 5 , n = 1 , 2 , 3 ). It is shown that the dipion mass spectra of these decays are explained by the unified mechanism related to the contribution of the multichannel π π scattering in the final states of these reactions. Since in the analysis the multichannel π π -scattering amplitudes did not change in comparison with the ones in our combined analysis of data on the multichannel π π scattering and on the charmonia decays — J / ψ → ϕ ( π π , K K ¯ ) and ψ ( 2 S ) → J / ψ ( π π ) (from the Crystal Ball, DM2, Mark II, Mark III, and BES II) — the results confirm all our earlier conclusions on the scalar mesons.