Effect of the $\eta \eta$ channel and interference phenomena in the two-pion transitions of charmonia and bottomonia

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.

arXiv comment8 pages, 4 figures, Talk at the XXIII International Baldin Seminar on High Energy Physics Problems "Relativistic Nuclear Physics \& Quantum Chromodynamics" (Dubna, Russia, 19--24 September 2016). arXiv admin note: text overlap with arXiv:1610.07898

References in corpus (8)

• Observation of ${\rm Y}(4S)decaysto$π^+pi^-Υ(1S)$and$π^+pi^-Υ(2S)
• Study of Di-Pion Transitions Among Upsilon(3S), Upsilon(2S), and Upsilon(1S) States
• Bottomonium dipion transitions
• Observation of the decay Upsilon(4S) -> Upsilon(1S) pi+ pi-
• On nature of the scalar-isoscalar mesons in the uniformizing-variable method based on analyticity and unitarity
• Masses and widths of scalar-isoscalar multi-channel resonances from data analysis
• Parameters of scalar resonances from the combined analysis of data on processes $\pi \pi \to \pi \pi ,K\bar{K},\eta \eta$ and $J/\psi$ decays
• Unified description of BaBar and Belle data on the bottomonia decays Upsilon(mS) -> Upsilon(nS) pi+ pi-