Observation of an isoscalar resonance with exotic $J^{PC}=1^{-+}$ quantum numbers in $J/\psi \to \gamma \eta {\eta }^{\prime }$

Abstract

Using a sample of (10.09$\pm$0.04)$\times$10${}^9$ $J/\psi$ events collected with the BESIII detector operating at the BEPCII storage ring, a partial wave analysis of the decay $J/\psi \to \gamma \eta {\eta }^{\prime }$ is performed. The first observation of an isoscalar state with exotic quantum numbers $J^{PC}=1^{-+}$, denoted as ${\eta }_1(1855)$, is reported in the process $J/\psi \to \gamma {\eta }_1(1855)$ with ${\eta }_1(1855)\to \eta {\eta }^{\prime }$. Its mass and width are measured to be (1855$\pm$9${}_{-1}^{+6}$)MeV/$c^2$ and (188$\pm$18${}_{-8}^{+3}$)MeV, respectively, where the first uncertainties are statistical and the second are systematic, and its statistical significance is estimated to be larger than 19$\sigma$.

8 pages, 12 figures

References in corpus (9)

• Glueballs, Hybrids, Multiquarks. Experimental facts versus QCD inspired concepts
• Hybrid Mesons
• Number of $J/\psi$ events at BESIII
• Heavy quarkonium hybrids from Coulomb gauge QCD
• Decays of an exotic $1^{-+}$ hybrid meson resonance in QCD
• Scalar isoscalar mesons and the scalar glueball from radiative $J/\psi$ decays
• Partial wave analysis of $J/\psi \to \gamma \eta {\eta }^{\prime }$
• Energy spectrum of the low-lying gluon excitations in the Coulomb gauge
• The Strong Decay Patterns of the $1^{-+}$ Exotic Hybrid Mesons

Cited by in corpus (38)

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• Radiative production and decays of the exotic ${\eta }_1^{\prime }(1855)$ and its siblings
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• Light double-gluon hybrid states from QCD sum rules
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• Kinematical higher-twist corrections in ${\gamma }^{\ast }\to M_1{M}_2\gamma$: Neutral meson production
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