# $\mathbf {{{\boldsymbol \eta}{(2100)}}}$ $\boldsymbol I\boldsymbol G(\boldsymbol J{}^{PC}) = 0{}^{+}(0{}^{-+})$ INSPIRE search

MASS ${\mathrm {(MeV)}}$ WIDTH ${\mathrm {(MeV)}}$ EVTS DOCUMENT ID TECN  COMMENT
$2050 {}^{+30}_{-24} {}^{+75}_{-26}$ 250+36-30+181-164 1
 2016 N
BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit K}^{+}}$ ${{\mathit K}^{-}}{{\mathit K}^{+}}{{\mathit K}^{-}}$
$2103 \pm50$ 187+-75 586 2
 1989 B
DM2 ${{\mathit J / \psi}}$ $\rightarrow$ 4 ${{\mathit \pi}}{{\mathit \gamma}}$
1  From a partial wave analysis of ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \phi}}{{\mathit \phi}}$ , for which the primary signal is ${{\mathit \eta}{(2225)}}$ $\rightarrow$ ${{\mathit \phi}}{{\mathit \phi}}$ , and that also finds significant signals for for ${}^{}0{}^{-+}$ phase space, ${{\mathit f}_{{0}}{(2100)}}$, ${{\mathit f}_{{2}}{(2010)}}$, ${{\mathit f}_{{2}}{(2300)}}$, ${{\mathit f}_{{2}}{(2340)}}$, and a previously unseen ${}^{}0{}^{-+}$ state ${{\mathit X}{(2500)}}$ (M = $2470$ ${}^{+15}_{-19}{}^{+101}_{-23}$ MeV, $\Gamma$ = $230$ ${}^{+64}_{-35}{}^{+56}_{-33}$ MeV).
2  ASTON 1981B sees no peak, has 850 events in Ajinenko+Barth bins. ARESTOV 1980 sees no peak.
References:
 ABLIKIM 2016N
PR D93 112011 Observation of Pseudoscalar and tensor Resonances in ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \phi}}{{\mathit \phi}}$
 BISELLO 1989B
PR D39 701 First Observation of Three Pseudoscalar States in the ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \rho}}{{\mathit \rho}}$ Decay