Fully strange tetraquark states via QCD sum rules

In this paper, we have systematically explored the mass spectrum of fully strange tetraquark candidates within the framework of QCD sum rules, focusing on states with quantum numbers $J^{PC}=0^{++}$, $0^{-+}$, $0^{–}$, $1^{–}$, $1^{+-}$, and $1^{++}$. The analysis reveals the existence of fully strange tetraquark states with masses ranging from approximately $2.07$ to $3.12$ GeV. These predictions are confronted with existing experimental observations of potential fully strange tetraquark resonances, notably the $X(2300)$ recently reported by the BESIII Collaboration, which may be interpreted as a fully strange tetraquark state. Furthermore, the possible decay modes of these fully strange tetraquark states are analyzed, providing guidance for their identification in current and future high energy experiments such as BESIII, Belle II, and LHCb.

💡 Research Summary

In this work the authors perform a systematic QCD‑sum‑rule investigation of fully strange tetraquark states composed of two strange quarks and two strange antiquarks ($ss\bar s\bar s$). The study focuses on six $J^{PC}$ quantum numbers: $0^{++}$, $0^{-+}$, $0^{–}$, $1^{–}$, $1^{+-}$ and $1^{++}$. For each quantum number a set of interpolating currents is constructed in a molecular configuration, i.e. as products of two colour‑singlet meson‑like bilinears $