scholarly journals Analysis of the X(3842) as a D-wave charmonium meson

2019 ◽  
Vol 34 (26) ◽  
pp. 1950151
Author(s):  
Guo-Liang Yu ◽  
Zhi-Gang Wang
Keyword(s):  
Experimental Data ◽  
Operator Product Expansion ◽  
Mass Formula ◽  
Decay Constant ◽  
Sum Rules ◽  
Lhcb Collaboration ◽  
Operator Product ◽  
Strong Decay ◽  
State Formula ◽  
Vacuum Condensates

In this paper, we assign the newly reported state [Formula: see text] to be a [Formula: see text]-wave [Formula: see text] meson, and study its mass and decay constant with QCD sum rules by considering the contributions of vacuum condensates up to dimension-6 in the operator product expansion. The predicted mass [Formula: see text] GeV is in agreement with the experimental data [Formula: see text] MeV from the LHCb collaboration. This result supports assigning [Formula: see text] as the [Formula: see text] charmonium meson. In this case, its predicted strong decay width with the [Formula: see text] decay model is compatible with the experimental data.

scholarly journals Analysis of the D̄Σc, D̄Σc∗, D̄∗Σc and D̄∗Σc∗ pentaquark molecular states with QCD sum rules

2019 ◽  
Vol 34 (19) ◽  
pp. 1950097 ◽  
Author(s):  
Zhi-Gang Wang
Keyword(s):  
Operator Product Expansion ◽  
Sum Rules ◽  
Molecular State ◽  
Operator Product ◽  
Qcd Sum Rules ◽  
Dimension Formula ◽  
Vacuum Condensates

In this paper, we study the [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] pentaquark molecular states with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of dimension [Formula: see text] in a consistent way. The present calculations support assigning the [Formula: see text] to be the [Formula: see text] pentaquark molecular state with [Formula: see text], assigning the [Formula: see text] to be the [Formula: see text] pentaquark molecular state with [Formula: see text], assigning the [Formula: see text] to be the [Formula: see text] pentaquark molecular state with [Formula: see text] or the [Formula: see text] pentaquark molecular state with [Formula: see text]. Special attention is paid to the operator product expansion.

scholarly journals Analysis of the Pc(4312), Pc(4440), Pc(4457) and related hidden-charm pentaquark states with QCD sum rules

2020 ◽  
Vol 35 (01) ◽  
pp. 2050003 ◽  
Author(s):  
Zhi-Gang wang
Keyword(s):  
Mass Spectrum ◽  
Ground State ◽  
Operator Product Expansion ◽  
Sum Rules ◽  
Operator Product ◽  
Qcd Sum Rules ◽  
Type Formula ◽  
Vacuum Condensates

In this paper, we restudy the ground state mass spectrum of the diquark–diquark–antiquark-type [Formula: see text] pentaquark states with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of dimension 13 in a consistent way. The predicted masses support assigning the [Formula: see text] to be the hidden-charm pentaquark state with [Formula: see text], assigning the [Formula: see text] to be the hidden-charm pentaquark state with [Formula: see text], [Formula: see text] or [Formula: see text], assigning the [Formula: see text] to be the hidden-charm pentaquark state with [Formula: see text] or [Formula: see text].

BARYONIC SUM RULES IN THE NEXT-TO-LEADING ORDER IN αs

1991 ◽  
Vol 06 (11) ◽  
pp. 2025-2034 ◽  
Author(s):  
A.A. OVCHINNIKOV ◽  
A.A. PIVOVAROV ◽  
L.R. SURGULADZE
Keyword(s):  
Experimental Data ◽  
Operator Product Expansion ◽  
Sum Rules ◽  
Operator Product ◽  
Leading Order ◽  
Perturbative Corrections

The perturbative corrections of order αs to the coefficient functions of the operator product expansion for the baryonic correlator are calculated. These corrections change considerably the numerical values of the mass and residue for the proton extracted from the sum rules and improve the agreement between the theoretical estimates and experimental data.

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].

scholarly journals Does vacuum saturation work for the higher-dimensional vacuum condensates in the QCD sum rules?

2021 ◽  
Author(s):  
Zhi-Gang Wang
Keyword(s):  
Operator Product Expansion ◽  
Sum Rules ◽  
Operator Product ◽  
Qcd Sum Rules ◽  
Text Type ◽  
Factorization Approximation ◽  
Vacuum Saturation ◽  
Higher Dimensional ◽  
Vacuum Condensates ◽  
Saturation Approximation

In the QCD sum rules for the tetraquark (molecular) states, the higher-dimensional vacuum condensates play an important role in extracting the tetraquark masses. We carry out the operator product expansion up to the vacuum condensates of dimension-10 and observe that the vacuum condensates of dimensions 6, 8 and 10 have the same expressions but opposite signs for the [Formula: see text]-type and [Formula: see text]-type four-quark currents, which make their influences distinguishable, and they are excellent channels to examine the vacuum saturation approximation. We introduce a parameter [Formula: see text] to parametrize the derivation from the vacuum saturation or factorization approximation, and choose two sets of parameters to examine the influences on the predicted tetraquark masses, which can be confronted to the experimental data in the future. In all the channels, smaller value of the [Formula: see text] leads to better convergent behavior in the operator product expansion, which favors the vacuum saturation approximation.

scholarly journals The ground states and the first radially excited states of D-wave vector ρ and ϕ mesons

2021 ◽  
Author(s):  
Guo-Liang Yu ◽  
Zhi-Gang Wang ◽  
Xiu-Wu Wang ◽  
Hui-Juan Wang
Keyword(s):  
Excited States ◽  
Wave Vector ◽  
Operator Product Expansion ◽  
Sum Rules ◽  
Ground States ◽  
Operator Product ◽  
Decay Constants ◽  
Vector Formula ◽  
Vacuum Condensates ◽  
D Wave

In this paper, we first derive two QCD sum rules QCDSR I and QCDSR II which are, respectively, used to extract observable quantities of the ground states and the first radially excited states of the D-wave vector [Formula: see text] and [Formula: see text] mesons. In our calculations, we consider the contributions of vacuum condensates up to dimension-7 in the operator product expansion. The predicted masses for [Formula: see text] [Formula: see text] meson and [Formula: see text] [Formula: see text] meson are consistent well with the experimental data of [Formula: see text]([Formula: see text]) and [Formula: see text]([Formula: see text]), respectively. Besides, our analysis indicates that it is reliable to assign the recent reported [Formula: see text]([Formula: see text]) state as the [Formula: see text] [Formula: see text] meson. Finally, we obtain the decay constants of these states with QCDSR I and QCDSR II. These predictions are helpful not only to reveal the structure of the newly observed [Formula: see text]([Formula: see text]) state, but also to establish [Formula: see text] meson and [Formula: see text] meson families.

scholarly journals Tetraquark state candidates: Y(4140), Y(4274) and X(4350)

2015 ◽  
Vol 30 (01) ◽  
pp. 1550004 ◽  
Author(s):  
Zhi-Gang Wang ◽  
Ye-Fan Tian
Keyword(s):  
Operator Product Expansion ◽  
Sum Rules ◽  
Numerical Results ◽  
Operator Product ◽  
Tetraquark State ◽  
Spectral Densities ◽  
Qcd Sum Rules ◽  
Tensor Formula ◽  
Vacuum Condensates

In this paper, we tentatively assign the Y(4140), Y(4274) and X(4350) to be the scalar and tensor [Formula: see text] tetraquark states, respectively, and study them with the QCD sum rules. In the operator product expansion, we take into account the vacuum condensates up to dimension-10. In calculations, we use the formula [Formula: see text] to determine the energy scales of the QCD spectral densities. The numerical results favor assigning the Y(4140) to be the JPC = 2++ diquark–antidiquark type tetraquark state, and disfavor assigning the Y(4274) and X(4350) to be the 0++ or 2++ tetraquark states.

scholarly journals Analysis of the triply heavy baryon states with the QCD sum rules

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Zhi-Gang Wang
Keyword(s):  
Mass Spectrum ◽  
Ground State ◽  
Operator Product Expansion ◽  
Sum Rules ◽  
Heavy Baryon ◽  
Operator Product ◽  
Qcd Sum Rules ◽  
Gluon Condensates ◽  
First Time ◽  
Vacuum Condensates

AbstractIn this article, we reexamine the mass spectrum of the ground state triply heavy baryon states with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of dimension 6 in a consistent way and preforming a novel analysis. It is for the first time to take into account the three-gluon condensates in the QCD sum rules for the triply heavy baryon states.

scholarly journals The lowest hidden charmed tetraquark state from QCD sum rules

2014 ◽  
Vol 29 (39) ◽  
pp. 1450207 ◽  
Author(s):  
Zhi-Gang Wang
Keyword(s):  
Sum Rules ◽  
Coupling Constants ◽  
Operator Product ◽  
Total Width ◽  
Tetraquark State ◽  
Qcd Sum Rules ◽  
Text Type ◽  
State Formula ◽  
Belle Ii ◽  
Vacuum Condensates

In this paper, we study the [Formula: see text] type scalar tetraquark state [Formula: see text] in detail with the QCD sum rules by calculating the contributions of the vacuum condensates up to dimension 10 in the operator product expansion, and obtain the value [Formula: see text], which is the lowest mass for the hidden charmed tetraquark states from the QCD sum rules. Furthermore, we calculate the hadronic coupling constants GZcηcπand GZcDDwith the three-point QCD sum rules, then study the strong decays Zc→ηcπ, DD, and observe that the total width ΓZc≈21 MeV . The present predictions can be confronted with the experimental data in the future at the BESIII, LHCb and Belle-II.

scholarly journals SCALAR NONETS IN POLE-DOMINATED QCD SUM RULES

2008 ◽  
Vol 23 (27n30) ◽  
pp. 2230-2233
Author(s):  
TORU KOJO ◽  
DAISUKE JIDO
Keyword(s):  
Operator Product Expansion ◽  
Quark Mass ◽  
Sum Rules ◽  
Operator Product ◽  
Qcd Sum Rules ◽  
Current Quark Mass ◽  
Pole Dominance ◽  
Light Scalar ◽  
Current Quark

The light scalar nonets are studied using the QCD sum rules for the tetraquark operators. The operator product expansion for the correlators is calculated up to dimension 12 and this enables us to perform analyses retaining sufficient pole-dominance. To classify the light scalar nonets, we investigate the dependence on current quark mass and flavor dynamics. Especially, to examine the latter, we study separately SU(3) singlet and octet states, and show that the number of annihilation diagrams is largely responsible for their differences, which is also the case even after the inclusion of the finite quark mass. Our results support the tetraquark picture for isosinglets, while that for octets is not conclusive yet.

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