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

Abstract

The effect of isoscalar S-wave processes [Formula: see text] is considered in the analysis of data (from the ARGUS, CLEO, CUSB, Crystal Ball, Belle, BABAR collaborations) on the bottomonia decays — [Formula: see text] ([Formula: see text]). It is shown that the dipion mass spectra of these decays are explained by the unified mechanism related to the contribution of the multichannel [Formula: see text] scattering in the final states of these reactions. Since in the analysis the multichannel [Formula: see text]-scattering amplitudes did not change in comparison with the ones in our combined analysis of data on the multichannel [Formula: see text] scattering and on the charmonia decays — [Formula: see text] and [Formula: see text] (from the Crystal Ball, DM2, Mark II, Mark III, and BES II) — the results confirm all our earlier conclusions on the scalar mesons.