Effect of the $K\overline{K}$ and $\eta\eta$ channels and interference phenomena in the two-pion and $K\overline{K}$ transitions of charmonia and bottomonia

TL;DR

This paper explains the shapes of dipion and kaon-antikaon mass spectra in various quarkonium decays through a unified mechanism involving coupled channels and interference effects, highlighting the role of scalar resonances.

Contribution

It introduces a unified model based on coupled channel contributions and interference phenomena to explain mass spectra in quarkonium decays, emphasizing the impact of scalar resonances.

Findings

Mass spectra shapes explained by coupled channels and interference

Role of $f_0$ resonances in decay spectra clarified

Unified mechanism applicable to multiple decay processes

Abstract

It is shown that the basic shape of dipion and $K\overline{K}$ mass spectra in decays $J/\psi\to\phi(\pi\pi,K\overline{K})$, $\psi(2S)\to J/\psi\,\pi\pi$, $Y(4260)\to J/\phi~\pi\pi$ and in the two-pion transitions of bottomonia states are explained by an unified mechanism based on the contribution of the $\pi\pi$, $K\overline{K}$ and $\eta\eta$ coupled channels including their interference. The role of the individual $f_0$ resonances in making up the shape of the dipion mass distributions in the charmonia and bottomonia decays is considered.