The Z_b(10610) and Z_b(10650) as axial-vector tetraquark states in the QCD sum rules

2013/12/31 by Zhi-Gang Wang, Tao Huang · 2 citations
Physics and Astronomy · #hep-ph #hep-ex

paper · pdf · doi:10.1016/j.nuclphysa.2014.08.084

published as Nucl.Phys.A930(2014)63-85 · 21 pages, 15 figures. arXiv admin note: substantial text overlap with arXiv:1312.1537, arXiv:1311.1046

arxiv created 2014/09/19 · arxiv updated 2014/09/22

Abstract

In this article, we study the axial-vector mesons Z_b(10610) and Z_b(10650) with the Cγ_μ-Cγ₅ type and Cγ_μ-Cγ_ν type interpolating currents respectively by carrying out the operator product expansion to the vacuum condensates up to dimension-10. In calculations, we explore the energy scale dependence of the QCD spectral densities of the hidden bottom tetraquark states in details for the first time, and suggest a formula μ=√M²_X/Y/Z-(2\mathbbM_b)² with the effective mass \mathbbM_b=5.13 \rmGeV to determine the energy scales. The numerical results favor assigning the Z_b(10610) and Z_b(10650) as the Cγ_μ-Cγ₅ type and Cγ_μ-Cγ_ν type hidden bottom tetraquark states, respectively. We obtain the mass of the J^PC=1⁺⁺ hidden bottom tetraquark state as a byproduct, which can be compared to the experimental data in the futures. Furthermore, we study the strong decays Z_b^±(10610)→Υπ^± , η_bρ^± with the three-point QCD sum rules, the decay widths also support assigning the Z_b(10610) as the Cγ_μ-Cγ₅ type hidden bottom tetraquark state.

Citations

• Analysis of the Z_c(4020), Z_c(4025), Y(4360) and Y(4660) as vector tetraquark states with QCD sum rules

Cited by

• The lowest hidden charmed tetraquark state from QCD sum rules
• Reanalysis of the Z_c(4020), Z_c(4025), Z(4050) and Z(4250) as tetraquark states with QCD sum rules