scholarly journals Analysis of the X0(2900) as the scalar tetraquark state via the QCD sum rules

2020 ◽  
Vol 35 (30) ◽  
pp. 2050187 ◽  
Author(s):  
Zhi-Gang Wang
Keyword(s):  
Sum Rules ◽  
Tetraquark State ◽  
Qcd Sum Rules ◽  
Spin Parity ◽  
Scalar Diquark

In this article, we study the axialvector-diquark–axialvector-antidiquark (AA)-type and scalar-diquark–scalar-antidiquark (SS) type fully open flavor [Formula: see text] tetraquark states with the spin-parity [Formula: see text] via the QCD sum rules. The predicted masses [Formula: see text] GeV and [Formula: see text] GeV support assigning the [Formula: see text] to be the AA-type scalar [Formula: see text] tetraquark state.

scholarly journals Assignments of the X 4140 , X 4500 , X 4630 , and X 4685 Based on the QCD Sum Rules

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhi-Gang Wang
Keyword(s):  
Excited State ◽  
Sum Rules ◽  
Molecular State ◽  
Tetraquark State ◽  
Qcd Sum Rules ◽  
Scattering States ◽  
Scattering State ◽  
Good Agreement

In this article, we take into account our previous calculations based on the QCD sum rules, and tentatively assign the X 4630 as the D s ∗ D ¯ s 1 − D s 1 D ¯ s ∗ tetraquark molecular state or c s P c ¯ s ¯ A + c s A c ¯ s ¯ P tetraquark state with the J P C = 1 − + , and assign the X 3915 and X 4500 as the 1S and 2S c s A c ¯ s ¯ A tetraquark states, respectively, with the J P C = 0 + + . Then, we extend our previous works to investigate the LHCb’s new tetraquark candidate X 4685 as the first radial excited state of the X 4140 with the QCD sum rules and obtain the mass M X = 4.70 ± 0.12   GeV , which is in very good agreement with the experimental value 4684 ± 7 − 16 + 13   MeV . Furthermore, we investigate the two-meson scattering state contributions in details and observe that the two-meson scattering states alone cannot saturate the QCD sum rules, the contributions of the tetraquark states play an unsubstitutable role, and we can saturate the QCD sum rules with or without the two-meson scattering states.

scholarly journals Analysis of strong decays of the Zc(4600) with the QCD sum rules

2019 ◽  
Vol 34 (20) ◽  
pp. 1950110 ◽  
Author(s):  
Zhi-Gang wang
Keyword(s):  
Experimental Data ◽  
Sum Rules ◽  
Tetraquark State ◽  
Qcd Sum Rules ◽  
Text Type ◽  
Decay Widths ◽  
The Future ◽  
Hadron Duality

In this paper, we tentatively assign the [Formula: see text] to be the [Formula: see text] type vector tetraquark state and study its two-body strong decays with the QCD sum rules based on solid quark–hadron duality, the predictions for the partial decay widths [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] can be compared to the experimental data in the future to diagnose the nature of the [Formula: see text].

QCD SUM RULES FOR THE $Z_c^+(3900)$ STATE

2014 ◽  
Vol 26 ◽  
pp. 1460069 ◽  
Author(s):  
F. S. NAVARRA ◽  
J. M. DIAS ◽  
M. NIELSEN ◽  
C. M. ZANETTI
Keyword(s):  
Experimental Data ◽  
Sum Rules ◽  
Coupling Constants ◽  
Tetraquark State ◽  
Point Function ◽  
Qcd Sum Rules ◽  
Decay Widths ◽  
Structure Formula ◽  
Good Agreement

We use the QCD sum rules to study the recently observed charmonium-like structure [Formula: see text] as a tetraquark state. We evaluate the three-point function and extract the coupling constants of the [Formula: see text] and [Formula: see text] vertices and the corresponding decay widths in these channels. The results obtained are in good agreement with the experimental data and supports to the tetraquark picture of this state.

scholarly journals Scalar fully-heavy tetraquark states $$QQ^\prime {\bar{Q}} \bar{Q^\prime }$$ in QCD sum rules

2021 ◽  
Vol 81 (4) ◽  
Author(s):  
Bo-Cheng Yang ◽  
Liang Tang ◽  
Cong-Feng Qiao
Keyword(s):  
Sum Rules ◽  
Lhcb Collaboration ◽  
Tetraquark State ◽  
Qcd Sum Rules ◽  
Quark Sector ◽  
The Masses ◽  
B Quark ◽  
Broad Structure ◽  
Narrow Structure ◽  
Formula Type

AbstractVery recently, the LHCb Collaboration observed distinct structures with the $$cc{\bar{c}}{\bar{c}}$$ c c c ¯ c ¯ in the $$J/\Psi $$ J / Ψ -pair mass spectrum. In this work, we construct four scalar ($$J^{PC} = 0^{++}$$ J PC = 0 + + ) $$[8_c]_{Q\bar{Q^\prime }}\otimes [8_c]_{Q^\prime {\bar{Q}}}$$ [ 8 c ] Q Q ′ ¯ ⊗ [ 8 c ] Q ′ Q ¯ type currents to investigate the fully-heavy tetraquark state $$Q Q^\prime {\bar{Q}} \bar{Q^\prime }$$ Q Q ′ Q ¯ Q ′ ¯ in the framework of QCD sum rules, where $$Q=c, b$$ Q = c , b and $$Q^\prime = c, b$$ Q ′ = c , b . Our results suggest that the broad structure around 6.2-6.8 GeV can be interpreted as the $$0^{++}$$ 0 + + octet–octet tetraquark states with masses $$6.44\pm 0.11$$ 6.44 ± 0.11 GeV and $$6.52\pm 0.10$$ 6.52 ± 0.10 GeV, and the narrow structure around 6.9 GeV can be interpreted as the $$0^{++}$$ 0 + + octet–octet tetraquark states with masses $$6.87\pm 0.11$$ 6.87 ± 0.11 GeV and $$6.96\pm 0.11$$ 6.96 ± 0.11 GeV, respectively. Extending to the b-quark sector,the masses of their fully-bottom partners are found to be around 18.38-18.59 GeV. Additionally, we also analyze the spectra of the $$[8_c]_{c{\bar{c}}}\otimes [8_c]_{b {\bar{b}}}$$ [ 8 c ] c c ¯ ⊗ [ 8 c ] b b ¯ and $$[8_c]_{c{\bar{b}}}\otimes [8_c]_{b {\bar{c}}}$$ [ 8 c ] c b ¯ ⊗ [ 8 c ] b c ¯ tetraquark states, which lie in the range of 12.51–12.74 GeV and 12.49–12.81 GeV, respectively.

scholarly journals Analysis of the Pcs(4459) as the hidden-charm pentaquark state with QCD sum rules

2021 ◽  
Vol 36 (10) ◽  
pp. 2150071
Author(s):  
Zhi-Gang Wang
Keyword(s):  
Experimental Data ◽  
Mass Spectrum ◽  
Excellent Agreement ◽  
Mass Formula ◽  
Sum Rules ◽  
Lhcb Collaboration ◽  
Qcd Sum Rules ◽  
Breaking Effect ◽  
Type Formula ◽  
Scalar Diquark

In this paper, we study the scalar-diquark–scalar-diquark–antiquark-type [Formula: see text] pentaquark state with the QCD sum rules, the predicted mass [Formula: see text] is in excellent agreement with the experimental data [Formula: see text] from the LHCb collaboration, and supports assigning the [Formula: see text] to be the hidden-charm pentaquark state with the spin-parity [Formula: see text]. We take into account the flavor [Formula: see text] mass-breaking effect, and estimate the mass spectrum of the diquark–diquark–antiquark-type [Formula: see text] pentaquark states with the strangeness [Formula: see text].

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