scholarly journals Large-Nc masses of light mesons from QCD sum rules for nonlinear radial Regge trajectories

2018 ◽  
Vol 33 (12) ◽  
pp. 1850069 ◽  
Author(s):  
S. S. Afonin ◽  
T. D. Solomko
Keyword(s):  
Sum Rules ◽  
Linear Part ◽  
Operator Product ◽  
Regge Trajectories ◽  
Pseudoscalar Mesons ◽  
Light Vector ◽  
Original Analysis ◽  
Point Correlation ◽  
Spectral Sum Rules ◽  
The Given

The large-[Formula: see text] masses of light vector, axial, scalar and pseudoscalar mesons are calculated from QCD spectral sum rules for a particular ansatz interpolating the radial Regge trajectories. The ansatz includes a linear part plus exponentially degreasing corrections to the meson masses and residues. The form of corrections was proposed some time ago for consistency with analytical structure of Operator Product Expansion of the two-point correlation functions. We revised that original analysis and found the second solution for the proposed sum rules. The given solution describes better the spectrum of vector and axial mesons.

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 XYZ-SU3 breakings from Laplace sum rules at higher orders

2018 ◽  
Vol 33 (16) ◽  
pp. 1850082 ◽  
Author(s):  
R. Albuquerque ◽  
S. Narison ◽  
D. Rabetiarivony ◽  
G. Randriamanatrika
Keyword(s):  
Sum Rules ◽  
Chiral Limit ◽  
Axial Vector ◽  
Operator Product ◽  
Leading Order ◽  
Spectral Functions ◽  
Quark State ◽  
Future Data ◽  
The Masses ◽  
Spectral Sum Rules

We present new compact integrated expressions of SU3 breaking corrections to QCD spectral functions of heavy–light molecules and four-quark [Formula: see text]-like states at lowest order (LO) of perturbative (PT) QCD and up to [Formula: see text] condensates of the Operator Product Expansion (OPE). Including next-to-next-to-leading order (N2LO) PT corrections in the chiral limit and next-to-leading order (NLO) SU3 PT corrections, which we have estimated by assuming the factorization of the four-quark spectral functions, we improve previous LO results for the [Formula: see text]-like masses and decay constants from QCD spectral sum rules (QSSR). Systematic errors are estimated from a geometric growth of the higher order PT corrections and from some partially known [Formula: see text] nonperturbative contributions. Our optimal results, based on stability criteria, are summarized in Tables 18–21 while the [Formula: see text] and [Formula: see text] channels are compared with some existing LO results in Table 22. One can note that, in most channels, the SU3 corrections on the meson masses are tiny: [Formula: see text] (respectively [Formula: see text]) for the [Formula: see text] (respectively [Formula: see text])-quark channel but can be large for the couplings ([Formula: see text]). Within the lowest dimension currents, most of the [Formula: see text] and [Formula: see text] states are below the physical thresholds while our predictions cannot discriminate a molecule from a four-quark state. A comparison with the masses of some experimental candidates indicates that the [Formula: see text] [Formula: see text] might have a large [Formula: see text] molecule component while an interpretation of the [Formula: see text] candidates as four-quark ground states is not supported by our findings. The [Formula: see text] [Formula: see text] and [Formula: see text] are compatible with the [Formula: see text], [Formula: see text] molecules and/or with the axial-vector [Formula: see text] four-quark ground state. Our results for the [Formula: see text], [Formula: see text] and for different beauty states can be tested in the future data. Finally, we revisit our previous estimates1 for the [Formula: see text] and [Formula: see text] and present new results for the [Formula: see text].

scholarly journals XYZ-like spectra from Laplace sum rule at N2LO in the chiral limit

2016 ◽  
Vol 31 (36) ◽  
pp. 1650196 ◽  
Author(s):  
R. Albuquerque ◽  
S. Narison ◽  
F. Fanomezana ◽  
A. Rabemananjara ◽  
D. Rabetiarivony ◽  
...  
Keyword(s):  
Sum Rules ◽  
Chiral Limit ◽  
Operator Product ◽  
Theoretical Studies ◽  
Leading Order ◽  
Spectral Functions ◽  
Decay Constants ◽  
Heavy Quark Mass ◽  
The Masses ◽  
Spectral Sum Rules

We present new compact integrated expressions of QCD spectral functions of heavy-light molecules and four-quark [Formula: see text]-like states at lowest order (LO) of perturbative (PT) QCD and up to [Formula: see text] condensates of the Operator Product Expansion (OPE). Then, by including up to next-to-next leading order (N2LO) PT QCD corrections, which we have estimated by assuming the factorization of the four-quark spectral functions, we improve previous LO results from QCD spectral sum rules (QSSR), on the [Formula: see text]-like masses and decay constants which suffer from the ill-defined heavy quark mass. PT N3LO corrections are estimated using a geometric growth of the PT series and are included in the systematic errors. Our optimal results based on stability criteria are summarized in Tables 11–14 and compared, in Sec. 10, with experimental candidates and some LO QSSR results. We conclude that the masses of the [Formula: see text] observed states are compatible with (almost) pure [Formula: see text], [Formula: see text] molecule or/and four-quark states. The ones of the [Formula: see text], [Formula: see text] molecule/four-quark states are about 1.5 GeV above the [Formula: see text] mesons experimental candidates and hadronic thresholds. We also find that the couplings of these exotics to the associated interpolating currents are weaker than that of ordinary [Formula: see text] mesons [Formula: see text] and may behave numerically as [Formula: see text] (respectively [Formula: see text]) for the [Formula: see text], [Formula: see text] (respectively [Formula: see text], [Formula: see text]) states which can stimulate further theoretical studies of these decay constants.

scholarly journals Conformal Regge theory at finite boost

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Simon Caron-Huot ◽  
Joshua Sandor
Keyword(s):  
Field Theory ◽  
Operator Product Expansion ◽  
Operator Product ◽  
Exact Results ◽  
Double Integral ◽  
Regge Theory ◽  
Conformal Field ◽  
Regge Trajectories ◽  
Continuous Spins ◽  
Regge Limit

Abstract The Operator Product Expansion is a useful tool to represent correlation functions. In this note we extend Conformal Regge theory to provide an exact OPE representation of Lorenzian four-point correlators in conformal field theory, valid even away from Regge limit. The representation extends convergence of the OPE by rewriting it as a double integral over continuous spins and dimensions, and features a novel “Regge block”. We test the formula in the conformal fishnet theory, where exact results involving nontrivial Regge trajectories are available.

scholarly journals Determining Fπ from spectral sum rules

2006 ◽  
Vol 643 (3-4) ◽  
pp. 235-239 ◽  
Author(s):  
Magdalena Luz
Keyword(s):  
Sum Rules ◽  
Spectral Sum Rules

Baryons with two heavy quarks from QCD spectral sum rules

1993 ◽  
Vol 306 (3-4) ◽  
pp. 350-356 ◽  
Author(s):  
E. Bagan ◽  
M. Chabab ◽  
S. Narison
Keyword(s):  
Sum Rules ◽  
Heavy Quarks ◽  
Spectral Sum Rules

scholarly journals Sum Rules Based on Khuri Amplitudes and Degeneracy of Regge Trajectories

1969 ◽  
Vol 41 (4) ◽  
pp. 1057-1063 ◽  
Author(s):  
Toshiharu Kawai ◽  
Takesi Saito
Keyword(s):  
Sum Rules ◽  
Regge Trajectories

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.

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