Observation and Spin-Parity Determination of the $X(1835)$ in $J/\psi \to \gamma K_S^0{K}_S^0\eta$

Abstract

We report an observation of the process $J/\psi \to \gamma X(1835)\to \gamma K_S^0{K}_S^0\eta$ at low $K_S^0{K}_S^0$ mass with a statistical significance larger than 12.9$\sigma$ using a data sample of $1.31\times 10^9$ $J/\psi$ events collected with the BESIII detector. In this region of phase space the $K_S^0{K}_S^0$ system is dominantly produced through the $f_0(980)$. By performing a partial wave analysis, we determine the spin-parity of the $X(1835)$ to be $J^{PC}=0^{-+}$. The mass and width of the observed $X(1835)$ are $1844\pm 9(\text{stat}{)}_{-25}^{+16}(\text{syst})$~\MeV~and $192_{-17}^{+20}(\text{stat}{)}_{-43}^{+62}(\text{syst})$~MeV, respectively, which are consistent with the results obtained by BESIII in the channel $J/\psi \to \gamma {\pi }^{+}{\pi }^{-}{\eta }^{\prime }$.

Final version published in PRL

References in corpus (2)

• Study of psi(2S) Decays to gamma p bar{p}, pi^0 p bar{p} and eta p bar{p} and Search for p bar{p} Threshold Enhancements
• Baryonium, tetra-quark state and glue-ball in large N_c QCD

Cited by in corpus (17)

• An updated review of the new hadron states
• Observation of an anomalous line shape of the ${\eta }^{\prime }{\pi }^{+}{\pi }^{-}$ mass spectrum near the $p\bar{p}$ mass threshold in $J/\psi \to \gamma {\eta }^{\prime }{\pi }^{+}{\pi }^{-}$
• Determination of spin-parity quantum numbers of X(2370) as $0^{-+}$ from $J/\psi \to \gamma K_S^0{K}_S^0{\eta }^{\prime }$
• Observation of a state $X(2600)$ in the ${\pi }^{+}{\pi }^{-}{\eta }^{\prime }$ system in the process $J/\psi \to \gamma {\pi }^{+}{\pi }^{-}{\eta }^{\prime }$
• Study of $\eta (1475)$ and $X(1835)$ in radiative $J/\psi$ decays to $\gamma \varphi$
• Observation of the Anomalous Shape of $X(1840)$ in $J/\psi \to \gamma 3({\pi }^{+}{\pi }^{-})$ Indicating a Second Resonance Near $p\bar{p}$ Threshold
• Physics Accomplishments and Future Prospects of the BES Experiments at the BEPC Collider
• $J/\psi \to \gamma {\eta }^{\prime }{\pi }^{+}{\pi }^{-}$ and the structure observed around the $\bar{p}p$ threshold
• Observation of $J/\psi$ Electromagnetic Dalitz Decays to $X(1835)$, $X(2120)$ and $X(2370)$
• Study of light tetraquark spectroscopy
• Structure around $p\bar{p}$ threshold in $J/\psi$ radiative decays
• Measurement of the branching fraction of $J/\psi \to \omega {\eta }^{\prime }{\pi }^{+}{\pi }^{-}$ and search for $J/\psi \to \omega X(1835),X(1835)\to {\eta }^{\prime }{\pi }^{+}{\pi }^{-}$ decay
• Looking for bound states and resonances in the ${\eta }^{\prime }K\bar{K}$ system
• Highlights of recent BESIII results
• Coupled-channel analysis of the near-threshold $e^{+}{e}^{-}\to N\bar{N}$ cross sections
• Testing B-violating signatures from Exotic Instantons in future colliders
• Recent Results on Hadron Spectroscopy from BESIII