7,227 research outputs found
QCD Sum Rules and the Determination of Leading Twist Non-Singlet Operator Matrix Elements
We use QCD sum rules to determine directly the leading-twist non-singlet
operator matrix elements based on calculations of three-point correlator
functions in configuration space. We find a different result from that obtained
by integrating the structure functions' expressions obtained by Belyaev and
Ioffe based on calculations of four-point correlators in momentum space. The
origin of this discrepancy remains unclear.Comment: 9 pages, 5 figure
The derivative of the topological susceptibility at zero momentum and an estimate of mass in the chiral limit
The anomaly-anomaly correlator is studied using QCD sum rules. Using the
matrix elements of anomaly between vacuum and pseudoscalars and
, the derivative of correlator is evaluated and found to be
GeV. Assuming that has no
significant dependence on quark masses, the mass of in the chiral limit
is found to be 723 MeV. The same calculation also yields for the
singlet pseudoscalar decay constant in the chiral limit a value of MeV.Comment: LaTeX, 7 pages, 2 figures, uses cernrep.cls (included
Comment on "Remark on the external-field method in QCD sum rules"
It is proved, that suggested by Jin modified formalism in the external-field
method in QCD sum rules exactly coincides with the formalism used before.
Therefore, unlike the claims of ref.1, this formalism cannot improve the
predictability and reliability of external-field sum rule calculations in
comparison with those, done by the standard approach.
PACS number(s): 12.38.Lg, 11.55.HxComment: 5 pages, RevTe
Quark distributions in QCD sum rules: unexpected features and paradoxes
Some very unusual features of the hadron structure functions, obtained in the
generalized QCD sum rules, like the surprisingly strong difference between
longitudinally and transversally polarized mesons structure functions
and the strong suppression of the gluon sea in longitudinally polarized
mesons are discussed. Also the problem of exact zero contribution of gluon
condensates to pion and longitudinally polarized meson quark
distributions is discussed.Comment: 9 pages, 5 fig
Weak interaction contribution to the inclusive hadron-hadron scattering cross sections at high
It is demonstrated that the strong power-like scaling violation in the
transverse momentum distribution of inclusive hadron production, observed by
CDF Collaboration in collisions at Tevatron is caused by
contribution of weak interaction. The contribution of weak interaction is
increasing with energy at high energies.Comment: Talk presented at Gribov-80 Memorial Workshop, Trieste, May 26-28,
2010 and International seminar Quarks-2010, Colomna, June 6-12, 2010, 6
pages, 3 figures, it is accounted the weak boson formfactor, caused by strong
interactio
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