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

Rui-Rui Dong,Er-Liang Cui,Niu Su,Zhi-Yong Zhou,Hua-Xing Chen

doi:10.1140/epjc/s10052-020-8340-9

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.

Highlights

In the past 20 years there were a lot of exotic hadrons observed in particle experiments [1], which can not be well explained in the traditional quark model [2,3,4,5,6,7,8,9,10]
We have used the same approach in Refs. [20,21,22] to study the sssstetraquark states of J pole contribution (PC) = 1±−, where we found that there are only two independent sssstetraquark currents of J PC = 1−− as well as two of J PC = 1+−
Taking η1 as an example, first we investigate the convergence of the operator product expansion (CVG) by requiring the D = 10 terms to be less than 5%: CVG ≡

Summary

Introduction

In the past 20 years there were a lot of exotic hadrons observed in particle experiments [1], which can not be well explained in the traditional quark model [2,3,4,5,6,7,8,9,10]. In this paper we shall study the sssstetraquark states of. In the present study we shall find that there are only two independent ssssinterpolating currents of J PC = 0−+. This makes it possible to perform a rather complete. We shall use them to perform QCD sum rule analyses, and the obtained. The X (2500) is explained as the 51 S0 ssstate using the 3 P0 model in Refs. [29,30] and using the flux-tube model in Ref. More Lattice QCD studies can be found in Refs. We use them to perform QCD sum rule analyses, and calculate both their diagonal and off-diagonal two-point correlation functions.

Interpolating currents

QCD sum rule analysis

Single currents η1 and η2

Mixed currents J1 and J2

Summary and discussions