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Related papers: The Small-x Behaviour of the Singlet Polarized Str…

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We perform a full next-to-leading analysis of the the available experimental data on the polarized structure function g_1 of the nucleon, and give a precise determination of its singlet axial charge together with a thorough assessment of…

High Energy Physics - Phenomenology · Physics 2009-10-28 R. D. Ball , S. Forte , G. Ridolfi

The small $x$ behaviour of polarized parton distributions is related to non-leading reggeons in the framework of the high-energy effective action. Double-logarithmic contributions to the reggeon interaction beyond the ones included in the…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. Kirschner

The impact of the resummation of leading small-$x$ terms in the anomalous dimensions is briefly summarized for the evolution of non--singlet and singlet polarized structure functions.

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Blümlein , A. Vogt

We present the results of our QCD analysis for polarized quark distribution and structure function $xg_1 (x,Q^2)$. We use very recently experimental data to parameterize our model. New parameterizations are derived for the quark and gluon…

High Energy Physics - Phenomenology · Physics 2009-04-22 S. Atashbar Tehrani , Ali N. Khorramian

We obtain a pair of second order differential equations in two variables $x$ and $t$ from the coupled DGLAP QCD evolution equations at small $x$ using the standard Taylor series expansion method.To that end we keep terms upto $O(x^2 )$.We…

High Energy Physics - Phenomenology · Physics 2016-12-28 Luxmi Machahari , D. K. Choudhury , P. K. Sahariah

The double parton distribution functions are investigated in the region of small longitudinal momentum fractions in the leading logarithm approximation of perturbative QCD. It is shown that these functions have the factorization property in…

High Energy Physics - Phenomenology · Physics 2011-03-23 A. M. Snigirev

In the present paper we summarize our results on the structure function g_1 and present explicit expressions for the non-singlet and singlet components of g_1 which can be used at arbitrary x and Q^2. These expressions combine the…

High Energy Physics - Phenomenology · Physics 2014-11-18 B. I. Ermolaev , M. Greco , S. I. Troyan

We show that simple parametrisations at small x of the proton structure function work so well in limited regions of the $(x,Q^2)$ plane because they are approximately "self-consistent" solutions of the QCD evolution equation. For a class of…

High Energy Physics - Phenomenology · Physics 2022-03-02 L. L. Jenkovszky , A. Lengyel , F. Paccanoni

Nucleon resonance contributions to the polarized proton $g_1$ and $g_2$ structure functions are computed from resonance electroexcitation amplitudes extracted from CLAS exclusive meson electroproduction data. Including resonances in the…

High Energy Physics - Phenomenology · Physics 2023-03-21 A. N. Hiller Blin , V. I. Mokeev , W. Melnitchouk

A brief survey is given of recent results on the resummation of leading small-x terms for unpolarized and polarized non--singlet and singlet structure function evolution.

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Blümlein , S. Riemersma , A. Vogt

I present some comments on the relationship between the small-$x$ behaviour of the parton (quark and gluon) densities and the scaling violation of the proton structure function $F_{2}(x,Q^{2})$.

High Energy Physics - Phenomenology · Physics 2007-05-23 Stefano Catani

We review the theory of polarized structure functions measured in deep-inelastic lepton-nucleon scattering, focusing on the most recent developments. We concentrate on the structure function $g_1$, emphasizing the phenomenological problems…

High Energy Physics - Phenomenology · Physics 2009-09-25 Stefano Forte

The $Q^2$ evolution of polarised parton distributions at small $x$ is studied. Various analytic approximations are critically discussed. We compare the full evolution with that obtained from the leading-pole approximation to the splitting…

High Energy Physics - Phenomenology · Physics 2014-11-17 T. Gehrmann , W. J. Stirling

We discuss the quantitative consequences of the resummation of the small-x contributions to the anomalous dimensions beyond next-to-leading order in alpha_s and up to next order in ln(1/x) (NLx) in a framework based on the renormalization…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Blümlein , V. Ravindran , W. L. van Neerven , A. Vogt

Using an analytical parameterization for the behavior of the x slope of the structure function F_2 at small x in perturbative QCD, at the leading twist approximation of the Wilson operator product expansion, and applying a flat initial…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. V. Kotikov , G. Parente

We demonstrate how to calculate perturbative components of the structure functions F_1 (for unpolarized DIS) and g_1 (spin-dependent DIS) in Double-Logarithmic Approximation, studying separately the cases of fixed and running QCD coupling.…

High Energy Physics - Phenomenology · Physics 2020-01-29 B. I. Ermolaev , S. I. Troyan

The perturbative QCD predictions concerning deep inelastic scattering at low $x$ are summarized. The theoretical framework based on the leading log $1/x$ resummation and $k_t$ factorization theorem is described and some recent developments…

High Energy Physics - Phenomenology · Physics 2010-03-25 J. Kwiecinski

We perform an extensive study of the scale dependence of flavor-singlet contributions to the structure function g_2(x,Q^2) in polarized deep-inelastic scattering. We find that the mixing between quark-antiquark-gluon and three-gluon twist-3…

High Energy Physics - Phenomenology · Physics 2014-11-17 V. M. Braun , G. P. Korchemsky , A. N. Manashov

The small x behaviour of the non-singlet structure function is studied within the double logarithmic approximation (DLA) of perturbative QCD. Since there is neither $k_T$ nor $\theta$ ordering in the ladder Feynman graphs, the predicted…

High Energy Physics - Phenomenology · Physics 2016-09-01 B. I. Ermolaev , S. I. Manayenkov , M. G. Ryskin

We derive a unitarity relationship between the spin structure function $g_{LT}(x,Q^{2})=g_{1}(x,Q^{2})+g_{2}(x,Q^{2})$, the LT interference diffractive structure function and the spin-flip coupling of the pomeron to nucleons. Our…

High Energy Physics - Phenomenology · Physics 2009-10-31 I. P. Ivanov , N. N. Nikolaev , A. V. Pronyaev , W. Schäfer