QCD SUM RULE APPROACH TO THE K→VACUUM WEAK AMPLITUDE

1990 ◽  
Vol 05 (06) ◽  
pp. 1071-1091
Author(s):  
M.A. AHMED ◽  
M.S. RASHEED
Keyword(s):  
Matrix Element ◽  
Sum Rules ◽  
Finite Energy ◽  
The Other ◽  
Sum Rule ◽  
Rule Approach ◽  
The Matrix

We study the kaon-to-vaccum weak matrix element using the method of the QCD duality finite energy sum rules. It is found that the matrix element in question can be expressed as a sum of two terms: one behaving like ms−md and the other like [Formula: see text]. Detailed numerical estimates are also given.

scholarly journals REVIEW ON QCD SUM RULES CALCULATIONS FOR EXOTICS CHARMONIUM

2011 ◽  
Vol 02 ◽  
pp. 36-40
Author(s):  
MARINA NIELSEN
Keyword(s):  
Sum Rules ◽  
Mass Region ◽  
Qcd Sum Rules ◽  
Sum Rule ◽  
Rule Approach ◽  
New States

Many new states in the charmonium mass region were recently discovered by the BaBar, Belle and CDF Collaborations. We use the QCD Sum Rule approach to study the possible structure of some of these states.

LIGHT QUARK MASSES FROM QCD SUM RULES

2013 ◽  
Vol 28 (26) ◽  
pp. 1360016 ◽  
Author(s):  
KARL SCHILCHER
Keyword(s):  
Quark Mass ◽  
Strange Quark ◽  
Sum Rules ◽  
Light Quark ◽  
Finite Energy ◽  
Qcd Sum Rules ◽  
Sum Rule ◽  
Quark Masses ◽  
Strange Quark Mass

Recent QCD sum rule determinations of the light quark masses are reviewed. In the case of the strange quark mass, possible uncertainties are discussed in the framework of finite energy sum rules.

D(1±) AND Ds(1±) MESONS SPECTROSCOPY IN GAUSSIAN SUM RULES

2009 ◽  
Vol 18 (01) ◽  
pp. 161-174
Author(s):  
SHUIGUO WEN ◽  
JUEPING LIU
Keyword(s):  
Experimental Data ◽  
Quantum Chromodynamics ◽  
Sum Rules ◽  
Coupling Constants ◽  
Sum Rule ◽  
Gaussian Sum ◽  
Rule Approach

The Gaussian sum rules (GSRs) for the D(1±) and Ds(1±) mesons current are obtained by means of Laplacian transformation. Based on it, the GSRs for the mass and the coupling constants of D(1±) and Ds(1±) mesons are worked out. Using the standard input of quantum chromodynamics nonperturbative parameters, the corresponding curves and tables are presented. The results are in accordance well with the experimental data, and more well than those from the Borel sum rule approach.

scholarly journals AXIAL VECTOR CURRENT MATRIX ELEMENTS AND QCD SUM RULES

2006 ◽  
Vol 21 (25) ◽  
pp. 5099-5117 ◽  
Author(s):  
J. PASUPATHY ◽  
RITESH K. SINGH
Keyword(s):  
Matrix Element ◽  
External Field ◽  
Axial Vector ◽  
Vector Current ◽  
Axial Vector Current ◽  
Β Decay ◽  
Sum Rule ◽  
Bjorken Sum Rule ◽  
The Matrix ◽  
Hyperon Decays

The matrix element of the isoscalar axial vector current, [Formula: see text], between nucleon states is computed using the external field QCD sum rule method. The external field induced correlator, [Formula: see text], is calculated from the spectrum of the isoscalar axial vector meson states. Since it is difficult to ascertain, from QCD sum rule for hyperons, the accuracy of validity of flavor SU(3) symmetry in hyperon decays when strange quark mass is taken into account, we rely on the empirical validity of Cabbibo theory to determine the matrix element [Formula: see text] between nucleon states. Combining with our calculation of [Formula: see text] and the well-known nucleon β-decay constant allows us to determine [Formula: see text] occurring in the Bjorken sum rule. The result is in reasonable agreement with experiment. We also discuss the role of the anomaly in maintaining flavor symmetry and validity of OZI rule.

TWIST-THREE DISTRIBUTION AMPLITUDES AND OCTET CURRENT DECAY CONSTANTS OF η AND η': A QCD SUM RULE APPROACH

2009 ◽  
Vol 18 (05n06) ◽  
pp. 1318-1323
Author(s):  
J. P. SINGH
Keyword(s):  
Sum Rules ◽  
Light Quark ◽  
Axial Vector ◽  
Vector Current ◽  
Axial Vector Current ◽  
Qcd Sum Rules ◽  
Sum Rule ◽  
Decay Constants ◽  
Current Decay ◽  
Rule Approach

We investigate twist-three distribution amplitudes (DAs) of η and η' using QCD sum rules. Zeroth moments of light quark DAs of η and η' are evaluated and compared with those found in other approaches. The decay constants of the octet axial vector current in the η and η' system are also estimated.

scholarly journals The scalar and pseudoscalar hidden-charm tetraquark states with QCD sum rules

2018 ◽  
Vol 33 (14n15) ◽  
pp. 1850090
Author(s):  
Zun-Yan Di ◽  
Zhi-Gang Wang
Keyword(s):  
Experimental Data ◽  
Correlation Functions ◽  
Sum Rules ◽  
Qcd Sum Rules ◽  
Sum Rule ◽  
Rule Approach ◽  
Point Correlation ◽  
The Masses ◽  
Vacuum Condensates ◽  
Conserved Currents

Based on the diquark configuration, we construct the diquark–antidiquark interpolating tetraquark currents with [Formula: see text] and [Formula: see text], which can couple to the scalar and pseudoscalar tetraquark states, respectively, since they are not conserved currents. Then, we investigate their two-point correlation functions including the contributions of the vacuum condensates up to dimension-10 and extract the masses and pole residues of the tetraquark states with [Formula: see text] and [Formula: see text] through the QCD sum rule approach. The predicted masses can be confronted with the experimental data in the future. Moreover, we briefly discuss the possible decay patterns of the tetraquark states.

scholarly journals PION FORM FACTOR IN QCD SUM RULES WITH NONLOCAL CONDENSATES AND IN THE LOCAL-DUALITY APPROACH

2009 ◽  
Vol 24 (35n37) ◽  
pp. 2848-2857 ◽  
Author(s):  
A. P. BAKULEV ◽  
A. V. PIMIKOV ◽  
N. G. STEFANIS
Keyword(s):  
Form Factor ◽  
Sum Rules ◽  
Pion Form Factor ◽  
Analytic Perturbation Theory ◽  
Continuum Threshold ◽  
Sum Rule ◽  
Local Duality ◽  
Rule Approach ◽  
Duality Approach ◽  
The Continuum

We discuss the QCD sum-rule approach for the spacelike electromagnetic pion form factor in the O(αs) approximation. We show that the nonlocality of the condensates is a key point to include nonperturbative contributions to the pion form factor. We compare our results with the Local-Duality predictions and show that the continuum threshold s0(Q2) parameter is highly underestimated in the Local-Duality approach at Q2 ≳ 2 GeV 2. Using our fit for this parameter, [Formula: see text] and applying the fractional analytic perturbation theory, we estimate with an accuracy of the order of 1% the [Formula: see text] contribution to the pion's form factor.

COUPLING gϕa0γ AND gϕσγ IN LIGHT-CONE SUM-RULES

2010 ◽  
Vol 25 (12) ◽  
pp. 2475-2491 ◽  
Author(s):  
CHANG-QIAO DU ◽  
MING-ZHEN ZHOU
Keyword(s):  
Light Cone ◽  
Sum Rules ◽  
Coupling Constants ◽  
Sum Rule ◽  
Rule Approach

In this paper, we calculate the coupling constants gϕa0γ and gϕσγ by utilizing ω–ϕ mixing scheme and taking into account the contributions of the three-particle twist-4 distribution amplitudes of the photon in the light-cone sum-rule approach. Our results: (1) 0.130 ≤ gϕa0γ ≤ 0.194 is in agreement with the previous estimations of these coupling constants which obtained from phenomenological considerations but less than the experimental value gϕa0γ = 1.64±0.05; (2) 0.055 ≤ gϕσγ ≤ 0.076 is consistent with the phenomenological value and the experimental value gϕσγ = 0.060±0.008.

Pembobotan Berdasarkan Tingkat Kesamaan Semantik pada Metode Fuzzy Semi-Supervised Co-Clustering untuk Pengelompokkan Dokumen Teks

2014 ◽  
Vol 6 (2) ◽  
pp. 46-51
Author(s):  
Galang Amanda Dwi P. ◽  
Gregorius Edwadr ◽  
Agus Zainal Arifin
Keyword(s):  
Supervised Learning ◽  
Semantic Similarity ◽  
The Other ◽  
Classification Result ◽  
Document Similarity ◽  
The Matrix ◽  
Index Terms ◽  
Membership Value ◽  
Degree Of Similarity

Nowadays, a large number of information can not be reached by the reader because of the misclassification of text-based documents. The misclassified data can also make the readers obtain the wrong information. The method which is proposed by this paper is aiming to classify the documents into the correct group.  Each document will have a membership value in several different classes. The method will be used to find the degree of similarity between the two documents is the semantic similarity. In fact, there is no document that doesn’t have a relationship with the other but their relationship might be close to 0. This method calculates the similarity between two documents by taking into account the level of similarity of words and their synonyms. After all inter-document similarity values obtained, a matrix will be created. The matrix is then used as a semi-supervised factor. The output of this method is the value of the membership of each document, which must be one of the greatest membership value for each document which indicates where the documents are grouped. Classification result computed by the method shows a good value which is 90 %. Index Terms - Fuzzy co-clustering, Heuristic, Semantica Similiarity, Semi-supervised learning.

scholarly journals Unitarity in KK-graviton production, a case study in warped extra-dimensions

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
A. de Giorgi ◽  
S. Vogl
Keyword(s):  
Extra Dimensions ◽  
Sum Rules ◽  
Effective Theory ◽  
Higher Dimensional ◽  
Massive Spin ◽  
The Matrix ◽  
Dimensional Gravity ◽  
Warped Extra Dimensions ◽  
Kaluza Klein

Abstract The Kaluza-Klein (KK) decomposition of higher-dimensional gravity gives rise to a tower of KK-gravitons in the effective four-dimensional (4D) theory. Such massive spin-2 fields are known to be connected with unitarity issues and easily lead to a breakdown of the effective theory well below the naive scale of the interaction. However, the breakdown of the effective 4D theory is expected to be controlled by the parameters of the 5D theory. Working in a simplified Randall-Sundrum model we study the matrix elements for matter annihilations into massive gravitons. We find that truncating the KK-tower leads to an early breakdown of perturbative unitarity. However, by considering the full tower we obtain a set of sum rules for the couplings between the different KK-fields that restore unitarity up to the scale of the 5D theory. We prove analytically that these are fulfilled in the model under consideration and present numerical tests of their convergence. This work complements earlier studies that focused on graviton self-interactions and yields additional sum rules that are required if matter fields are incorporated into warped extra-dimensions.

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