Analysis of the hidden-bottom tetraquark mass spectrum with the QCD sum rules

Zhi-Gang Wang

doi:10.1140/epjc/s10052-019-7019-6

Abstract

In this article, we extend our previous work to study the mass spectrum of the ground state hidden-bottom tetraquark states with the QCD sum rules in a systematic way. The predicted hidden-bottom tetraquark masses can be confronted to the experimental data in the future to diagnose the nature of the Z_b states. In calculations, we observe that the scalar diquark states, the axialvector diquark states and the axialvector components of the tensor diquark state are all good diquarks in building the lowest tetraquark states.

Highlights

Introduction[7,31,32,33], we assign the Zb(10610), Zb(10650), Zc(3900) and Zc(4020) to be the diquark-antidiquark type axialvector tetraquark states, and study their masses with the QCD sum rules in details
Iannd2Z01b±1(,10th6e50B)eilnlethceoπll±abΥor(a1t,io2n, 3oSb)saenrvdeπd±thheb(1Z,b±2(P1)0m61a0ss) spectrum for the first time, the favored quantum numbers (Isospin, G-parity, Spin, Parity) are I G (J P ) = 1+(1+)[1]
The Belle collaboration updated the values of the masses and widths MZb(10610) = (10607.2 ± 2.0) MeV, MZb(10650) = (10652.2 ± 1.5) MeV, Zb(10610) = (18.4 ± 2.4) MeV and Zb(10650) = (11.5 ± 2.2) MeV [2], which are adopted in the Review of Particle Physics by the Particle Data Group [3]

Summary

Introduction

[7,31,32,33], we assign the Zb(10610), Zb(10650), Zc(3900) and Zc(4020) to be the diquark-antidiquark type axialvector tetraquark states, and study their masses with the QCD sum rules in details. We extend our previous work to study the mass spectrum of the hidden-bottom tetraquark states in a systematic way Those hidden-bottom tetraquark states may be observed at the LHCb, Belle II, CEPC (Circular Electron Positron Collider), FCC We take the scalar (S), axialvector (A, A), vector (V , V ) diquark operators and antidiquark operators as the basic building blocks to construct the tetraquark operators to study the mass spectrum of the hidden-bottom tetraquark states with the QCD sum rules in a systematic way. The article is arranged as follows: we derive the QCD sum rules for the masses and pole residues of the hiddenbottom tetraquark states in Sect. 2; in Sect. 3, we present the numerical results and discussions; Sect. 4 is reserved for our conclusion

QCD sum rules for the hidden-bottom tetraquark states

Numerical results and discussions

Conclusion