scholarly journals Extraction of light quark masses from sum rule analyses of axial vector and vector current Ward identities

1998 ◽  
Vol 57 (9) ◽  
pp. 5455-5467 ◽  
Author(s):  
Tanmoy Bhattacharya ◽  
Rajan Gupta ◽  
Kim Maltman
Keyword(s):  
Light Quark ◽  
Axial Vector ◽  
Vector Current ◽  
Ward Identities ◽  
Sum Rule ◽  
Quark Masses

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.

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.

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.

Problems with conventional sum rule analyses for the light quark masses and a new analysis of m

1998 ◽  
Vol 631 ◽  
pp. 497-501
Author(s):  
K. Maltman ◽  
R. Gupta ◽  
T. Bhattacharya
Keyword(s):  
Light Quark ◽  
Sum Rule ◽  
Quark Masses

scholarly journals Hölder Inequalities and QCD Sum-Rule Bounds on the Masses of Light Quarks

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 582-584
Author(s):  
T. G. Steele
Keyword(s):  
Lower Bound ◽  
Spectral Function ◽  
Sum Rules ◽  
Light Quark ◽  
Hölder Inequality ◽  
Sum Rule ◽  
Quark Masses ◽  
The Masses

QCD Laplace Sum-Rules must satisfy a fundamental Hölder inequality if they are to consistently represent an integrated hadronic spectral function. The Laplace sum-rules of pion currents is shown to violate this inequality unless the u and d quark masses are sufficiently large, placing a lower bound on mu+md, the SU(2)-invariant combination of the light-quark masses.

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