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

Abstract

We apply the method of QCD sum rules to study the s s {bar{s}} {bar{s}} tetraquark states of J^{PC} = 0^{-+}. We construct all the relevant s s {bar{s}} {bar{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} GeV, suggesting that the X(2370) or the X(2500) can be explained as the ss{bar{s}}{bar{s}} tetraquark state of J^{PC} = 0^{-+}. To verify this interpretation, we propose to further study the pi pi /K {bar{K}} invariant mass spectra of the J/psi rightarrow gamma pi pi eta ^prime /gamma K {bar{K}} eta ^prime decays in BESIII to examine whether there exists the f_0(980) resonance.