Synthesis of DGLAP and total resummation of leading logarithms for the nonsinglet spin str.pdfVIP

authorB.I. Ermolaev Synthesis of DGLAP and total resummation of leading logarithms for the non-singlet spin structure function g1 M. Greco Department of Physics and INFN, University Rome III, Rome, Italy S.I. Troyan St.Petersburg Institute of Nuclear Physics, 188300 Gatchina, Russia The explicit expressions for the non-singlet DIS structure function g1 at small x are obtained by 5 resumming the leading logarithmic contributions. The role played by the fits for the initial parton 0 densities currently used in the DGLAP on the small-x behavior of the non-singlet g1 is discussed. 0 Explicit expressions combining DGLAP with our results are presented. 2 PACS numbers: 12.38.Cy n u J I. INTRODUCTION 9 2 The non-singlet component of the spin structure function g1 have been investigated in great detail in deep inelastic 1 scattering (DIS) experiments. The standard theoretical framework for studying the DIS structure functions is provided NS 2 v by DGLAP[1]. In this approach, g1 (x, Q ) can be represented as a convolution of the coefficient functions and the 2 evolved quark distributions. Combining these results with appropriate fits for the initial quark distributions, provides 0 a good agreement with the available experimental data. 3 However, the DGLAP evolution eqs. were originally applied in a range of large x values, where higher-loop contri- 6 0 butions to the coefficient functions and the anomalous