1
T-matrix pole, 2 poles, 3 channels, including ${{\mathit \pi}}{{\mathit \pi}}$ scattering data from HYAMS 1975.
2
K-matrix pole. Isospin not determined, could be ${{\mathit \omega}{(1650)}}$ or ${{\mathit \phi}{(1680)}}$.
References:
ALBRECHT
2020
EPJ C80 453
Coupled channel analysis of ${\bar{p}p}\,\rightarrow \,\pi ^0\pi ^0\eta $, ${\pi ^0\eta \eta }$ and ${K^+K^-\pi ^0}$ at 900 MeV/c and of ${\pi \pi }$-scattering data
ABELE
1999D
PL B468 178
Antiproton Proton Annihilation at Rest into ${{\mathit K}_L^0}{{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit \pi}^{0}}$
CLELAND
1982B
NP B208 228
Resonance Production in the Reaction ${{\mathit \pi}^{\pm}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit K}_S^0}$ ${{\mathit K}^{\pm}}{{\mathit p}}$ at 30 and 50 ${\mathrm {GeV/}}\mathit c$