2026/07/22 by BESIII Collaboration · 1 voice
#hep-ex
With 10 billion J/ψ events collected at BESIII, the decay of X(2370)→ K*(892)0K0+c.c. is searched for via the J/ψ→γKS0KS0π0 process. No evidence of this decay mode is found, with B[J/ψ→γX(2370)] × B[ X(2370) → K*(892)0K0+c.c. → K0SK0Sπ0] < 2.7× 10-6 at the 90% confidence level. The suppression of the K*(892)K mode indicates the X(2370) as a flavor-singlet state. It is the first flavor-singlet light hadron observed above 1~\textrmGeV/c2. All BESIII measurements on the X(2370) are summarized. A dominant component of the lightest 0-+ glueball is essential for a natural and complete explanation of the properties of the X(2370)~\textemdash~the mass, spin-parity, high production rate in J/ψ radiative decays, decay pattern similarities to that of ηc, flavor-singlet property, narrow partial decay width, and suppression of radiative decays to ω and ϕ, since these properties are all consistent with the features of the lightest 0-+ glueball while other interpretations at present are disfavored. This supports that the lightest 0-+ glueball is the dominant constituent of the X(2370).