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 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 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 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].

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 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 Decay constants and masses of light tensor mesons (JP = 2+)

2015 ◽  
Vol 30 (18n19) ◽  
pp. 1550106
Author(s):  
R. Khosravi ◽  
D. Hatami
Keyword(s):  
Standard Model ◽  
Operator Product Expansion ◽  
Sum Rules ◽  
Operator Product ◽  
Qcd Sum Rules ◽  
Decay Constants ◽  
Quantum Numbers ◽  
The Standard Model ◽  
The Masses

The masses and decay constants of the light tensor mesons were calculated with quantum numbers [Formula: see text] in the framework of the QCD sum rules in the standard model. The non perturbative contributions up to dimension-5 are considered as important terms of the operator product expansion.

scholarly journals The large-Nc limit of borelized spectral sum rules and the slope of radial Regge trajectories

2018 ◽  
Vol 33 (18n19) ◽  
pp. 1850115 ◽  
Author(s):  
S. S. Afonin ◽  
T. D. Solomko
Keyword(s):  
Ground State ◽  
Sum Rules ◽  
Ground States ◽  
Phenomenological Method ◽  
Scalar Mesons ◽  
Regge Trajectories ◽  
Spectral Sum Rules ◽  
The Given ◽  
Vacuum Condensates

We put forward a new phenomenological method for calculating the slope of radial trajectories from values of ground states and vacuum condensates. The method is based on a large-[Formula: see text] extension of borelized spectral sum rules. The approach is applied to the light nonstrange vector, axial and scalar mesons. The extracted values of slopes proved to be approximately universal and are in the interval [Formula: see text] GeV2. As a by-product, the given method leads to prediction of the second radial trajectory with ground state mass lying near 0.6 GeV.

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.

AN OPERATOR PRODUCT EXPANSION ANALYSIS OF e+e-ANNIHILATION DATA

2013 ◽  
Vol 28 (25) ◽  
pp. 1360009 ◽  
Author(s):  
HUBERT SPIESBERGER
Keyword(s):  
Quantum Chromodynamics ◽  
Cross Section ◽  
Operator Product Expansion ◽  
Operator Product ◽  
Perturbative Quantum Chromodynamics ◽  
Power Corrections ◽  
Perturbative Quantum ◽  
Vacuum Condensates

Perturbative Quantum Chromodynamics combined with the operator product expansion is expected to provide a framework for the description of phenomena in hadron interactions including contributions of nonperturbative origin. Applied to the correlator of two electromagnetic currents, this framework can be confronted with e+e-annihilation into hadrons. Data from the total hadronic e+e-cross-section have become much more precise in recent years and the power corrections in the operator product expansion, i.e. the vacuum condensates are expected to be determined with higher precision than previously. We present an analysis of the condensates of dimensions d = 2, 4 and 6 and find reasonably stable results, though still within rather large errors. Our results are in agreement with values obtained from τ-decay. It also appears that the separation into isovector and isoscalar pieces introduces additional uncertainties and errors.

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