Renormalization scheme invariant analysis of the DIS structure functionsF 2 andF L

A renormalization scheme invariant analysis of the deep inelastic scattering structure functionF ₂ andF _L is performed. Expressions for the moments are given in this approach. We find a significant improvement of the agreement withR=σ _L /σ _T -SLAC data with respect to the conventional perturvative \((\overline {MS} )\) analysis. Higher twist corrections are also required confirming previous evidence.     

The property of maximal transcendentality for the universal anomalous dimension in the N = 4 SYM

We show the results for the universal anomalous dimension γ _uni(j) of Wilson twist-2 operators in the N = 4 Supersymmetric Yang-Mills theory.     

Small <Emphasis Type="Italic">x</Emphasis> behavior of parton distributions: a study of higher twist effects

We review the double asymptotic scaling phenomenon for the structure functions of the deepinelastic scattering process. We present an analytical parameterization of the contributions from the twist-two operators of the Wilson operator product expansion and power suppressed terms. Higher twist corrections to F ₂ at small x are studied for the case of a flat initial condition for the twist-two QCD evolution in the next-to-leading order approximation. Higher twist terms are estimated using two different approaches: one motivated by BFKL and the other motivated by the renormalon formalism. The results of the latter approach are in very good agreement with deep inelastic scattering data from HERA. The text was submitted by the authors in English.     

Gluon Evolution for the Berger-Block-Tan Form of the Structure Function F2

JETP Letters - We present a nonlinear modification of the evolution of the gluon density, obtained at small x from the Berger-Block-Tan form of the deep inelastic structure function F2 in the...     

Qcd-parameterization of quark and gluon distributions in the nucleon. The case of “hard” gluons

A new parameterization of quark and gluon distributions in the nucleon is suggested. In contrast to known parameterizations, it is compatible with the predictions of asymptotic-free theories and is, therefore, suitable for carrying out a comparison between QCD and experimental data. The case of “hard” gluons is investigated. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 111, No. 1, pp. 63–76, April, 1997.     

Q 2 dependence of the measured asymmetry A 1: A test of the Bjorken sum rule

We analyze the proton and deutron data on the spin-dependent asymmetry A ₁(x, Q ²), supposing that the DIS structure functions g ₁(x, Q ²) and F ₃(x, Q ²) have a similar Q ² dependence. As a result, we have found that Λ ₁ ^p −Λ ₁ ⁿ =0.190±0.038 at Q ²=10 GeV² and Λ ₁ ^p −Λ ₁ ⁿ =0.165±0.026 at Q ²=3 GeV²; these values are in the best agreement with the Bjorken sum rule predictions. Pis’ma Zh. éksp. Teor. Fiz. 65, No. 1, 9–14 (10 January 1997) Published in English in the original Russian journal. Edited by Steve Torstveit.