scholarly journals THE SECOND MOMENT OF THE STRUCTURE FUNCTION FOR PSEUDOSCALAR MESONS IN QCD SUM RULES

1996 ◽  
Vol 05 (01) ◽  
pp. 121-129
Author(s):  
YOSHINORI NISHINO
Keyword(s):  
Structure Function ◽  
Sum Rules ◽  
Qcd Sum Rules ◽  
Sum Rule ◽  
Second Moment ◽  
Flavor Structure ◽  
Pseudoscalar Mesons

We calculate the second moment [Formula: see text] of the flavor-singlet structure function [Formula: see text] for the pion and the kaon in the framework of the QCD sum rule, and investigate how the results depend on their flavor structure (quark contents). Our calculations give similar values of [Formula: see text] for these two mesons as a result of the cancellation among several non-small factors.

scholarly journals PION QUARK STRUCTURE IN QCD

2007 ◽  
Vol 22 (02n03) ◽  
pp. 654-658 ◽  
Author(s):  
A. P. BAKULEV ◽  
A. V. PIMIKOV
Keyword(s):  
High Precision ◽  
Present Status ◽  
Sum Rules ◽  
Distribution Amplitude ◽  
Qcd Sum Rules ◽  
Second Moment ◽  
Lattice Calculations ◽  
Quark Structure ◽  
Qcd Analysis

We describe the present status of the pion distribution amplitude as it originated from two sources: (i) a nonperturbative approach, based on QCD sum rules with nonlocal condensates and (ii) a NLO QCD analysis of the CLEO data on Fγγ*π(Q2), supplemented by the recent high-precision lattice calculations of the second moment of the pion distribution amplitude.

COMMENTS ON QCD SUM-RULE CALCULATIONS OF EXCLUSIVE TWO-BODY DECAYS OF CHARMED MESONS

1989 ◽  
Vol 04 (09) ◽  
pp. 877-883 ◽  
Author(s):  
LING-LIE CHAU ◽  
HAI-YANG CHENG
Keyword(s):  
Experimental Data ◽  
Sum Rules ◽  
Theoretical Calculations ◽  
Charmed Mesons ◽  
Qcd Sum Rules ◽  
Generic Structure ◽  
Sum Rule ◽  
Quark Diagram ◽  
Model Independent ◽  
Decays Of Charmed Mesons

Exclusive two-body decay amplitudes of charmed mesons evaluated by Blok and Shifman (BS) using QCD sum rules are analyzed using the model-independent quark-diagram scheme, which helps to pin point the generic structure of the BS calculations, and their difficulties when compared with the experimental data. We also point out what experimental improvements on the data and which new data are most helpful in sharpening these comparisons. Some comments on possible ways of further improving the theoretical calculations are 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.

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 QCD SUM RULES: INTERCROSSED RELATIONS FOR THE Σ0–Λ MASS SPLITTING

2005 ◽  
Vol 20 (04) ◽  
pp. 243-249 ◽  
Author(s):  
A. ÖZPINECI ◽  
S. B. YAKOVLEV ◽  
V. S. ZAMIRALOV
Keyword(s):  
Sum Rules ◽  
Mass Splitting ◽  
Qcd Sum Rules ◽  
Sum Rule

New relations between QCD Borel sum rules for masses of Σ0 and Λ hyperons are constructed. It is shown that starting from the sum rule for the Σ0 hyperon mass it is straightforward to obtain the corresponding sum rule for the Λ hyperon mass and vice versa.

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.

THE CHARMED PENTAQUARK Θc(3250) FROM QCD SUM RULES

2014 ◽  
Vol 26 ◽  
pp. 1460109
Author(s):  
MARINA NIELSEN ◽  
RAPHAEL M. ALBUQUERQUE ◽  
SU HOUNG LEE
Keyword(s):  
Sum Rules ◽  
Decay Channel ◽  
Babar Collaboration ◽  
Leading Order ◽  
Qcd Sum Rules ◽  
Sum Rule

We study, using the QCD sum rule framework, the possible existence of a charmed pentaquark that we call Θc(3250). In the QCD side we work at leading order in αs and consider condensates up to dimension 10. The mass obtained: mΘc = (3.21±0.13) GeV, is compatible with the mass of the structure seen by BaBar Collaboration in the decay channel [Formula: see text].

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