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 Light Tetraquark State Candidates

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Zhi-Gang Wang
Keyword(s):  
Excellent Agreement ◽  
Sum Rules ◽  
Tetraquark State ◽  
Qcd Sum Rules ◽  
The Masses

In this article, we study the axialvector-diquark-axialvector-antidiquark type scalar, axialvector, tensor, and vector sss¯s¯ tetraquark states with the QCD sum rules. The predicted mass mX=2.08±0.12 GeV for the axialvector tetraquark state is in excellent agreement with the experimental value 2062.8±13.1±4.2 MeV from the BESIII collaboration and supports assigning the new X state to be a sss¯s¯ tetraquark state with JPC=1+−. The predicted mass mX=3.08±0.11 GeV disfavors assigning ϕ2170 or Y2175 to be the vector partner of the new X state. As a byproduct, we obtain the masses of the corresponding qqq¯q¯ tetraquark states. The light tetraquark states lie in the region about 2 GeV rather than 1 GeV.

scholarly journals Masses of fully heavy tetraquarks $$QQ {\bar{Q}} {\bar{Q}}$$ in an extended relativized quark model

2020 ◽  
Vol 80 (9) ◽  
Author(s):  
Qi-Fang Lü ◽  
Dian-Yong Chen ◽  
Yu-Bing Dong
Keyword(s):  
Quark Model ◽  
Mass Spectra ◽  
Ground States ◽  
Lhcb Collaboration ◽  
Wave Functions ◽  
Recent Measurement ◽  
Heavy Quarkonium ◽  
Radial Excitation ◽  
Broad Structure ◽  
Narrow Structure

AbstractInspired by recent measurement of possible fully charmed tetraquarks in LHCb Collaboration, we investigate the mass spectra of fully heavy tetraquarks $$QQ {\bar{Q}} {\bar{Q}}$$ Q Q Q ¯ Q ¯ in an extended relativized quark model. Our estimations indicate that the broad structure around 6.4 GeV should contain one or more ground states for $$cc {\bar{c}} {\bar{c}}$$ c c c ¯ c ¯ tetraquarks, while the narrow structure near 6.9 GeV can be categorized as the first radial excitation of $$cc {\bar{c}} {\bar{c}}$$ c c c ¯ c ¯ system. Moreover, with the wave functions of the tetraquarks and mesons, the strong decays of tetraquarks into heavy quarkonium pair are qualitatively discussed, which can be further checked by the LHCb and CMS Collaborations.

scholarly journals Thermal Properties of Light Tensor Mesons via QCD Sum Rules

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
K. Azizi ◽  
A. Türkan ◽  
E. Veli Veliev ◽  
H. Sundu
Keyword(s):  
Thermal Properties ◽  
Finite Temperature ◽  
Sum Rules ◽  
Temperature Dependent ◽  
Qcd Sum Rules ◽  
Continuum Threshold ◽  
Decay Constants ◽  
Good Consistency ◽  
Theoretical Predictions ◽  
The Masses

The thermal properties off2(1270),a2(1320), andK2*(1430) light tensor mesons are investigated in the framework of QCD sum rules at finite temperature. In particular, the masses and decay constants of the light tensor mesons are calculated taking into account the new operators appearing at finite temperature. The numerical results show that, at the point at which the temperature-dependent continuum threshold vanishes, the decay constants decrease with amount of (70–85)% compared to their vacuum values, while the masses diminish about (60–72)% depending on the kinds of the mesons under consideration. The results obtained at zero temperature are in good consistency with the experimental data as well as the existing theoretical predictions.

scholarly journals Analysis of the heavy quarkonium states hc and hb with QCD sum rules

2014 ◽  
Vol 29 ◽  
pp. 1460233
Author(s):  
Zhi-Gang Wang ◽  
Shu-Yuan Guo
Keyword(s):  
Experimental Data ◽  
Sum Rules ◽  
P Wave ◽  
Heavy Quarkonium ◽  
Qcd Sum Rules ◽  
Decay Constants ◽  
Spin Singlet ◽  
Structure Formula ◽  
Quark Structure ◽  
The Masses

In this article, we take the tensor currents [Formula: see text] to interpolate the P-wave spin-singlet heavy quarkonium states hQ, and study the masses and decay constants with the Borel sum rules and moments sum rules. The masses and decay constants from the Borel sum rules and moments sum rules are consistent with each other, the masses are also consistent with the experimental data. The heavy quarkonium states hQ couple potentially to the tensor currents [Formula: see text], and have the quark structure ϵijkξ†σkζ besides the quark structure [Formula: see text].

scholarly journals Analysis of Radial Excitations of Octet Baryons in QCD Sum Rules

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
T. M. Aliev ◽  
S. Bilmis
Keyword(s):  
Ground State ◽  
Sum Rules ◽  
Qcd Sum Rules ◽  
Linear Combinations ◽  
The Masses ◽  
Good Agreement ◽  
Octet Baryons

Using the QCD sum rules method, we estimate the mass and residues of the first radial excitations of octet baryons. The contributions coming from the ground state baryons are eliminated by constructing the linear combinations of the sum rules corresponding to different Lorentz structures. Our predictions of the masses of the first radial excitations of octet baryons are in good agreement with the data.

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.

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