QCD sum rule studies on the $$s s {\bar{s}} {\bar{s}}$$ tetraquark states of $$J^{PC} = 0^{-+}$$

Abstract

AbstractWe apply the method of QCD sum rules to study the $$s s {\bar{s}} {\bar{s}}$$sss¯s¯ tetraquark states of $$J^{PC} = 0^{-+}$$JPC=0-+. We construct all the relevant $$s s {\bar{s}} {\bar{s}}$$sss¯s¯ tetraquark currents, and find that there are only two independent ones. We use them to further construct two weakly-correlated mixed currents. One of them leads to reliable QCD sum rule results and the mass is extracted to be $$2.51^{+0.15}_{-0.12}$$2.51-0.12+0.15 GeV, suggesting that the X(2370) or the X(2500) can be explained as the $$ss{\bar{s}}{\bar{s}}$$sss¯s¯ tetraquark state of $$J^{PC} = 0^{-+}$$JPC=0-+. To verify this interpretation, we propose to further study the $$\pi \pi /K {\bar{K}}$$ππ/KK¯ invariant mass spectra of the $$J/\psi \rightarrow \gamma \pi \pi \eta ^\prime /\gamma K {\bar{K}} \eta ^\prime $$J/ψ→γππη′/γKK¯η′ decays in BESIII to examine whether there exists the $$f_0(980)$$f0(980) resonance.