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Predictions for the spin dependent structure function $g_1$ of the nucleon are presented. We use an unified approach incorporating the LO DGLAP evolution and the resummation of double logarithmic terms $ln^2(x)$. We show, that the singular…

High Energy Physics - Phenomenology · Physics 2008-10-06 Dorota Kotlorz , Andrzej Kotlorz

We incorporate the next-to-leading order (NLO) and the next-to-next-to-leading order (NNLO) effects in the models of the Singlet Structure function F_2^S(x,t) and the gluon distribution G(x,t) using DGLAP equations approximated at small x.…

High Energy Physics - Phenomenology · Physics 2024-11-28 Luxmi Machahari , D. K. Choudhury

We calculate the perturbative component of the DIS structure function F_1 singlet in the Double-Logarithmic Approximation (DLA) and account at the same time for the running QCD coupling effects. By constructing and solving evolution…

High Energy Physics - Phenomenology · Physics 2018-03-06 B. I. Ermolaev , S. I. Troyan

A generalization of the leading-order DGLAP evolution at small x is performed for the non-singlet structure function by resumming the leading-order DGLAP anomalous dimension to all orders in the QCD coupling. Explicit expressions are…

High Energy Physics - Phenomenology · Physics 2010-03-25 B. I. Ermolaev , M. Greco , S. I. Troyan

A unified equation for the non-singlet spin dependent structure function $g_1^{ns}(x,Q^2)$ which incorporates the complete leading order Altarelli-Parisi evolution at finite $x$ and double logarithmic $ ln^2(1/x)$ effects at $x \to 0$ is…

High Energy Physics - Phenomenology · Physics 2014-11-17 B. Badełek , J. Kwieciński

The explicit expressions for the non-singlet DIS structure function g_1 at small $x$ are obtained by resumming the leading logarithmic contributions. The role played by the fits for the initial parton densities currently used in the DGLAP…

High Energy Physics - Phenomenology · Physics 2009-11-11 B. I. Ermolaev , M. Greco , S. I. Troyan

We show that it is possible to use hard-Pomeron behavior to the gluon distribution and singlet structure function at low $x$. We derive a second-order independent differential equation for the gluon distribution and the singlet structure…

High Energy Physics - Phenomenology · Physics 2014-02-05 B. Rezaei , G. R. Boroun

Spin dependent structure function $g_1^{\gamma}(x,Q^2)$ of the polarised photon is analysed within the formalism based upon the unintegrated spin dependent parton distributions incorporating the LO Altarelli-Parisi evolution and the double…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. Kwiecinski , B. Ziaja

We present a formalism and explicit results for two-loop flavor singlet evolution kernels of skewed parton distributions in the minimal subtraction scheme. This approach avoids explicit multiloop calculations in QCD and is based on the…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. V. Belitsky , A. Freund , D. Müller

A semi-numerical solution to Dokshitzer- Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations at leading order (LO), next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) in the small-x limit is presented. Here we have…

High Energy Physics - Phenomenology · Physics 2012-10-10 Mayuri Devee , R. Baishya , J. K. Sarma

The proton spin dependent structure function $g_1^p$ is analysed using the unified scheme incorporating both Altarelli-Parisi evolution and the double $ln^2(1/x)$ effects at low $x$. The latter are found to be very important in the region…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Kwiecinski , B. Ziaja

We review the perturbative evolution of the polarized structure functions g_1 and their associated parton distribution functions, with particular emphasis on the anomalous coupling of the first moment of the polarized gluon distribution. We…

High Energy Physics - Phenomenology · Physics 2008-02-03 R. D. Ball

We discuss perturbative evolution of the polarized structure function g_1 in the (x,Q^2) plane, with special regard to the small-x region. We determine g_1 in terms of polarized quark and gluon distributions using coefficient functions to…

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

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

The explicit expressions for the non-singlet and singlet components of the DIS structure function g_1 comprising the DGLAP -expressions for the coefficient functions and the anomalous dimensions, and accounting for the total resummation of…

High Energy Physics - Phenomenology · Physics 2017-08-23 B. I. Ermolaev , M. Greco , S. I. Troyan

The impact of the resummed next-to-leading logarithmic small-$x$ contributions to the anomalous dimension $\gamma_{gg}$ is evaluated for the unpolarized parton densities and structure functions of the nucleon. These new terms diminish the…

High Energy Physics - Phenomenology · Physics 2016-09-06 J. Blümlein , A. Vogt

The Standard Approach (SA) for description of the structure function g_1 combines the DGLAP evolution equations and Standard Fits for the initial parton densities. The DGLAP equations describe the region of large Q^2 and large x, so there…

High Energy Physics - Phenomenology · Physics 2007-07-13 B. I. Ermolaev , M. Greco , S. I. Troyan

First results of a non--singlet QCD analysis of the structure function $F_2(x,Q^2)$ in 3--loop order based on the non--singlet world data are presented. Correlated errors are determined and their propagation through the evolution equations…

High Energy Physics - Phenomenology · Physics 2009-11-10 J. Blümlein , H. Böttcher , A. Guffanti

Accounting for double-logarithms of x and running QCD coupling leads to expressions for both the non-singlet and singlet components of $g_1$. These expressions manifest the Regge asymptotics when x ->0 and differ considerably from the DGLAP…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. I. Ermolaev , M. Greco , S. I. Troyan

We study the small $x$ diffractive contribution to the spin--dependent proton structure function $g_1(x)$. We find that the $x\to 0$ behaviour of $ g_1(x)$ has a singular form like $1/(x^\alpha \ln^2(x))$ with $\alpha \sim 0.2-0.3$.

High Energy Physics - Phenomenology · Physics 2008-02-03 S. V. Goloskokov