Effect of theηηchannel and interference phenomena in the two-pion transitions of charmonia and bottomonia

Yu.S Surovtsev,M Nagy,T Gutsche,P Bydžovský,R Kamiński,V.E Lyubovitskij

doi:10.1051/epjconf/201713801025

Abstract

The basic shape of di-pion mass spectra in the two-pion transitions of both charmonia and bottomonia states is explained by an unified mechanism based on contributions of the $\pi\pi$, $K\overline{K}$ and $\eta\eta$ coupled channels including their interference. The role of the individual $f_0$ resonances in shaping the di-pion mass distributions in the charmonia and bottomonia decays is considered.

Highlights

In this contribution we report on new results in continuation of our study of scalar meson properties analyzing jointly the data on the isoscalar S-wave processes ππ → ππ, KK, ηη and on the two-pion transitions of heavy mesons, when it is reasonable to consider that the two-pion pair is produced in the S-wave state and the final meson remains a spectator
Since studying the decays of charmonia and bottomonia, we investigated the role of the individual f0 resonances in contributing to the shape of the di-pion mass distributions in these decays, firstly we studied their role in forming the energy dependence of amplitudes of reactions ππ → ππ, KK, ηη
The combined analysis was performed for the data on isoscalar S-wave processes ππ → ππ, KK, ηη and on the decays of the charmonia — J/ψ → φππ, ψ(2S ) → J/ψ ππ — and of the bottomonia — Υ(mS ) → Υ(nS )ππ (m > n, m = 2, 3, 4, 5, n = 1, 2, 3) from the ARGUS, Crystal Ball, CLEO, CUSB, DM2, Mark II, Mark III, BES II, BaBar, and Belle Collaborations

Summary

Introduction

In this contribution we report on new results in continuation of our study of scalar meson properties analyzing jointly the data on the isoscalar S-wave processes ππ → ππ, KK, ηη and on the two-pion transitions of heavy mesons, when it is reasonable to consider that the two-pion pair is produced in the S-wave state and the final meson remains a spectator. The basic shape of di-pion mass spectra in the two-pion transitions of both charmonia and bottomonia states is explained by a unified mechanism based on contributions of the ππ, KK, and ηη coupled channels including their interference.

Results

Conclusion