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Related papers: Low x double $ln^2(1/x)$ resummation effects at th…

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We comment on the uniqueness of t-evolution$(t=log(Q^2/\Lambda^2))$ of non-singlet structure functions at low x obtained fromDGLAP equations.

High Energy Physics - Phenomenology · Physics 2007-05-23 D K Choudhury , Atri Deshamukhya

Total resummation of leading logarithms of x contributing to the spin-dependent structure function g_1 ensures its steep rise at small x. DGLAP lacks such a resummation. Instead, the DGLAP expressions for g_1 are complemented with special…

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

Inspired by recent measurements with the CLAS detector at Jefferson Lab, we perform a self-consistent analysis of world data on the proton structure function g1 in the range 0.17 < Q2 < 30 (GeV/c)**2. We compute for the first time low-order…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Osipenko , S. Simula , W. Melnitchouk , P. Bosted , V. Burkert , E. Christy , K. Griffioen , C. Keppel , S. Kuhn , G. Ricco

The numerical effects of the known all-order leading and next-to-leading logarithmic small-$x$ contributions to the anomalous dimensions and coefficient functions of the unpolarized singlet evolution are discussed for the structure…

High Energy Physics - Phenomenology · Physics 2009-10-30 J. Blümlein , A. Vogt

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

We present generalized evolution equations and factorization in terms of the truncated Mellin moments (TMM) of the parton distributions and structure functions. We illustrate the $x$ and $Q^2$ dependence of TMM in the polarized case. Using…

High Energy Physics - Phenomenology · Physics 2016-12-09 D. Kotlorz , A. Kotlorz

We examine the behaviour of the polarised structure function data for g_1(x) in the region of small x (~0.01 to 0.1) for the various available targets (proton, neutron and deuteron) with the aim of clarifying what may be safely deduced with…

High Energy Physics - Phenomenology · Physics 2007-05-23 Mehrdad Goshtasbpour , Philip G. Ratcliffe

We report a semi-analytical approach for the solution of the nonlinear Gribov-Levin-Ryskin-Mueller-Qiu (GLR-MQ) evolution equation for sea quark distribution and investigate the effect of gluon shadowing on the small-x and moderate-Q^2…

High Energy Physics - Phenomenology · Physics 2018-08-09 Mayuri Devee

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 summarize our recent results on small x resummation in full QCD with n_f quark flavours and discuss their phenomenological impact in the extraction of parton distributions from present day structure function data and their extrapolation…

High Energy Physics - Phenomenology · Physics 2009-04-14 Guido Altarelli , Richard D Ball , Stefano Forte

This is a review of experimental and phenomenological investigations of the nucleon spin dependent structure function $g_1$ at low values of $x$ and $Q^2$.

High Energy Physics - Phenomenology · Physics 2014-11-17 Barbara Badelek

The spin-dependent structure functions g_2 (x, Q^2) are investigated within the framework of the chiral quark soliton model. It turns out that the twist-3 part of g_2 (x, Q^2) gives nonnegligible contributions to the total distributions at…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Wakamatsu

Theoretical predictions for polarized nucleon structure function $g_1(x,Q^2)$ at low $Q^2$ are obtained in the framework of the Generalized Vector Meson Dominance model. Contributions from both light and heavy vector mesons are evaluated.…

High Energy Physics - Phenomenology · Physics 2011-09-13 Barbara Badełek , Jan Kwieciński , Beata Ziaja

A measurement of the derivative (d ln F_2 / d lnx)_(Q^2)= -lambda(x,Q^2) of the proton structure function F_2 is presented in the low x domain of deeply inelastic positron-proton scattering. For 5*10^(-5)<=x<=0.01 and Q^2>=1.5 GeV^2,…

High Energy Physics - Experiment · Physics 2010-03-25 H1 Collaboration , C. Adloff

We present an extraction of the lowest three moments of the proton longitudinal structure function F_L from world data between Q^2 = 0.75 and 45 (GeV/c)^2. The availability of new F_L data at low Bjorken x from HERA and at large x from…

Nuclear Experiment · Physics 2013-10-22 P. Monaghan , A. Accardi , M. E. Christy , C. E. Keppel , W. Melnitchouk , L. Zhu

The proton structure function F2 is studied in the low x regime using BFKL evolution. The next to leading logarithmic (NLL) analysis requires the inclusion of running coupling effects which lead to off-diagonal terms in the evolution…

High Energy Physics - Phenomenology · Physics 2012-06-12 M. Hentschinski , A. Sabio Vera , C. Salas

We present the next-to-next-to-leading order ($\alpha \alpha_s^2$) corrections to the first moment of the polarized virtual photon structure function $g_1^\gamma(x,Q^2,P^2)$ in the kinematical region $Q^2\gg P^2 \gg \Lambda^2$ in QCD. We…

High Energy Physics - Phenomenology · Physics 2007-05-23 T. Ueda , T. Uematsu , K. Sasaki

Power-suppressed corrections to parton evolution may affect the theoretical accuracy of current determinations of parton distributions. We study the role of multigluon-exchange terms in the extraction of the gluon distribution for the Large…

High Energy Physics - Phenomenology · Physics 2008-11-26 F. Hautmann

Explicit expressions for the singlet g_1 at small x and small Q^2 are obtained with the total resummation of the leading logarithmic contributions. It is shown that g_1 practically does not depend on Q^2 in this kinematic region. In…

High Energy Physics - Phenomenology · Physics 2008-11-26 B. I. Ermolaev , M. Greco , S. I. Troyan

We study the effect of absorptive corrections due to parton recombination on the parton distributions of the proton. A more precise version of the GLRMQ equations, which account for non-linear corrections to DGLAP evolution, is derived. An…

High Energy Physics - Phenomenology · Physics 2014-11-18 G. Watt , A. D. Martin , M. G. Ryskin