537 research outputs found
NNLO QCD contributions to the flavor non-singlet sector of
We present the results of our QCD analysis for nonsinglet unpolarized quark
distributions and structure function . New parameterizations are
derived for the nonsinglet quark distributions for the kinematic wide range of
and . The analysis is based on the Jacobi polynomials expansion of the
structure function. The higher twist contributions of proton and deuteron
structure function are obtained in the large region. Our calculations for
nonsinglet unpolarized quark distribution functions based on the Jacobi
polynomials method are in good agreement with the other theoretical models. The
values of and are determined.Comment: 29 pages, 8 figure
Light-quark masses and renormalons
A brief review of the problem of the determination of light-quark masses from
QCD sum rules for the correlators of scalar and pseudoscalar currents is given.
Special attention is paid to the description of the large- results,
obtained in collaboration with Broadhurst and Maxwell, for the scalar
correlator, and estimates of its higher-order perturbative uncertainties within
the renormalon-inspired large- expansion in the
scheme are given. Brief discussion is presented of the results of calculations
of higher-order perturbative QCD corrections to the relation between pole and
-scheme running-quark masses. Their comparison with the
different estimates is also given.Comment: 14 pages, Contributed to the Proceedings of Quarks-2000 International
Seminar, May 2000, Pushkin, Russia; minor typos are removed, 2 referencies
are adde
Neutrino deep-inelastic scattering: new experimental and theoretical results
A review of recent experimental and theoretical studies of characteristics of
neutrino deep-inelastic scattering is presented. Special attentition is paid to
the determination of and non-perturbative effects from QCD
fits to data at different orders of perturbation theory, with the help
of several theoretical methods.Comment: 17 pages, 3 figures; Contributed to the Proceedings of Les Recontre
de la Vallee d'Aosta, La Thuile, Italy, March 4-10, 2001; more careful
estimates of theoretical uncertainties of alpha_s(N_Z) with 3 significant
digits is presented
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