Exotic fully heavy QQ¯QQ¯ tetraquark states in 8[QQ¯]⊗8[QQ¯] color configuration

Qi-Nan Wang,Wei Chen,Zi-Yan Yang

doi:10.1103/physrevd.104.114037

Qi-Nan Wang, Wei Chen + Show 1 more

Open Access

https://doi.org/10.1103/physrevd.104.114037

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Abstract

We have systematically calculated the mass spectra for S-wave and P-wave fully-charm $c\bar{c}c\bar{c}$ and fully-bottom $b\bar{b}b\bar{b}$ tetraquark states in the $\mathbf{8}_{[Q\bar{Q}]}\otimes \mathbf{8}_{[Q\bar{Q}]}$ color configuration, by using the moment QCD sum rule method. The masses for the fully-charm $c\bar cc\bar c$ tetraquark states are predicted about $6.3-6.5$ GeV for S-wave channels and $7.0-7.2$ GeV for P-wave channels. These results suggest the possibility that there are some $\mathbf{8}_{[c\bar{c}]}\otimes \mathbf{8}_{[c\bar{c}]}$ components in LHCb's di-$J/\psi$ structures. For the fully-bottom $b\bar{b}b\bar{b}$ system, their masses are calculated around 18.2 GeV for S-wave tetraquark states while 18.4-18.8 GeV for P-wave ones, which are below the $\eta_b\eta_b$ and $\Upsilon(1S)\Upsilon(1S)$ two-meson decay thresholds.

Highlights

The existence of multiquark states was first suggested by Gell-Mann and Zweig at the birth of the quark model [1,2]
To understand the nature of these new resonances, many exotic hadron configurations have been proposed such as hadron molecules, compact multiquarks, hybrid mesons, and so on [13,14,15,16,17,18]
In our previous works in Refs. [23,79,80], we have studied the fully heavy tetraquark states in diquark-antidiquark configuration with both 61⁄2QQ ⊗ 6 ̄1⁄2Q Q and 3 ̄1⁄2QQ ⊗ 31⁄2Q Q color structures

Summary

INTRODUCTION

The existence of multiquark states was first suggested by Gell-Mann and Zweig at the birth of the quark model [1,2]. In 2019, the ANDY Collaboration at RHIC reported evidence of a significance peak at around 18.12 GeV [20] These structures were not confirmed by some other experiments [21,22], their observations still attracted a lot of research interest in fully heavy tetraquark states [23,24,25,26,27,28,29,30,31,32]. One should note that these tetraquark interpolating currents with 81⁄2QQ ⊗ 81⁄2QQ color structure can be written as combinations of the diquarkantidiquark operators through the Fierz transformation and the color rearrangement Their decay properties should be the same with the 1⁄2QQ1⁄2Q Q tetraquark states as discussed in Refs. We shall not discuss the decay behaviors for these 1⁄2QQ 1⁄2QQ tetraquarks in this work

INTERPOLATING CURRENTS

QCD SUM RULES

NUMERICAL ANALYSIS

CONCLUSION AND DISCUSSION