22,958 research outputs found
coupling constant in light cone QCD sum rules
We employ the light cone QCD sum rules to calculate coupling
constant by studying the two point correlation function between the vacuum and
the pion state. Our result is consistent with the traditional QCD sum rules
calculations and it is in agreement with the experimental value.Comment: 8 pages, latex, 2 figure
Nucleons on the light-cone: Theory and phenomenology of baryon distribution amplitudes
This is a short review of the theory and phenomenology of baryon distribution
amplitudes, including recent applications to the studies of nucleon form
factors at intermediate momentum transfers using the light-cone sum rule
approach.Comment: 16 pages, talk at CAQCD2006, Minneapoli
Ultraviolet dominance of power corrections in QCD?
I explain current theoretical ideas on higher-twist (hadronization)
corrections to physical observables in QCD.Comment: 7 pages, LATEX, no figures; Presented at 5th International Conference
on Physics Beyond the Standard Model, Balholm, Norway, 29 Apr - 4May 199
Deep Inelastic Scattering Beyond Perturbation Theory
I discuss possibilities to observe the instanton-induced contributions to
deep inelastic scattering which correspond to nonperturbative exponential
corrections to the coefficient functions in front of parton distributions of
the leading twist.Comment: Talk given at the Leipzig workshop on High Energy Physics,
Kyffhaeuser, September 20-24,1993, LATEX, 12 pages, 3 figures included as
uu-encoded file, MPI-Ph/93-7
Electroproduction of Resonances at Large Momentum Transfers
Measurements of transition form factors for the electro-excitation of nucleon
resonances in the Q^2=5-14 GeV^2 region can provide one with the information on
quark wave functions at small transverse separations. In particular a
comparison of form factors for the states of opposite parity can give insight
in the mechanisms of chiral symmetry breaking. I discuss perspectives of the
theoretical description of such reactions using a combination of lattice
calculations and light-cone sum rulesComment: 10 pages, 5 figures. Contribution to the Proceedings of the 4th
Workshop on Exclusive Reactions at High Momentum Transfer, May 18-21, 2010
Thomas Jefferson National Accelerator Facility Newport News, Virginia US
Renormalons and Power Corrections
Even for short-distance dominated observables the QCD perturbation expansion
is never complete. The divergence of the expansion through infrared renormalons
provides formal evidence of this fact. In this article we review how this
apparent failure can be turned into a useful tool to investigate power
corrections to hard processes in QCD.Comment: 56 pages, LaTeX, sprocl.sty. To be published in the Boris Ioffe
Festschrift ``At the Frontier of Particle Physics/Handbook of QCD'', edited
by M. Shifman (World Scientific, Singapore, 2001
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