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Related papers: New type of parametrizations for parton distributi…

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We describe how to calculate the parton distributions $f_a(x, k_t^2, \mu^2)$, unintegrated over the parton transverse momentum $k_t$, from auxiliary functions $h_a(x, k_t^2)$, which satisfy single-scale evolution equations. The formalism…

High Energy Physics - Phenomenology · Physics 2014-11-17 M. A. Kimber , A. D. Martin , M. G. Ryskin

Quantum statistical distributions for the partons provide a fair description of deep inelastic scattering data at $Q^2 = 3$ and $10 (GeV/c)^2$. The study of the polarized structure functions seems to suggest an alternative possible solution…

High Energy Physics - Phenomenology · Physics 2009-10-28 F. Buccella , G. Miele , N. Tancredi

By describing a large class of deep inelastic processes with standard parameterization for the different parton species, we check the characteristic relationship dictated by Pauli principle: broader shapes for higher first moments. Indeed,…

High Energy Physics - Phenomenology · Physics 2009-10-30 F. Buccella , I. Dorsner , O. Pisanti , L. Rosa , P. Santorelli

We discuss the statistical properties of parton distributions within the framework of the NNPDF methodology. We present various tests of statistical consistency, in particular that the distribution of results does not depend on the…

Using realistic quark propagators and meson Bethe-Salpeter amplitudes based on the Dyson-Schwinger equations, we calculate the pion and kaon's valence parton distribution functions (PDF) through the modified impulse approximation. The PDFs…

Nuclear Theory · Physics 2018-10-03 Chao Shi , Cedric Mezrag , Hong-shi Zong

A model for the parton distributions in hadrons is derived from simple physical arguments leading to an analytical expression for the valence distributions. The sea parton distributions arise mainly from pions in hadronic fluctuations.…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Edin , G. Ingelman , K. Torokoff

Generalized parton distributions (GPDs) are studied at the hadronic (nonperturbative) scale within different assumptions based on a relativistic constituent quark model. In particular, by means of a meson-cloud model we investigate the role…

High Energy Physics - Phenomenology · Physics 2009-11-11 S. Boffi , B. Pasquini , M. Traini

Nuclear parton distributions are studied in a parton model with rescaling and recombination mechanisms. Parton x distributions are first calculated at Q^2=1 GeV^2 by the model, and they are evolved to larger Q^2 in order to be compared with…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Kumano , K. Umekawa

We recently derived an explicit expression for the gluon distribution function G(x, Q^2) = xg(x, Q^2) in terms of the proton structure function F_2^{\gamma p} (x, Q^2) in leading-order (LO) QCD by solving the the LO DGLAP equation for the…

High Energy Physics - Phenomenology · Physics 2010-03-25 Martin M. Block , Loyal Durand , Douglas W. McKay

An analytical solution based on the Laplace transformation technique for the DGLAP evolution equations is presented at next-to-leading order accuracy in perturbative QCD. This technique is also applied to extract the analytical solution for…

High Energy Physics - Phenomenology · Physics 2017-03-09 Hamzeh Khanpour , Abolfazl Mirjalili , S. Atashbar Tehrani

We present a factorization formula for valence quark distributions in a hadron in x-->1 limit. For the example of pion, we arrive at the form of factorization by analyzing momentum flow in the leading and high-order Feynman diagrams. The…

High Energy Physics - Phenomenology · Physics 2010-04-05 Xiangdong Ji , Jian-Ping Ma , Feng Yuan

In this paper we make predictions for nondiagonal parton distributions in a proton in the LLA. We calculate the DGLAP-type evolution kernels in the LLA, solve the nondiagonal GLAP evolution equations with a modified version of the…

High Energy Physics - Phenomenology · Physics 2014-11-17 L. L. Frankfurt , A. Freund , V. Guzey , M. Strikman

Based on a field theoretically inspired model of light-cone wave functions, we derive valence-like generalized parton distributions and their double distributions from the wave function overlap in the parton number conserved s-channel. The…

High Energy Physics - Phenomenology · Physics 2008-11-26 D. S. Hwang , D. Mueller

We study the Q^2 evolution of parton distributions at small x values, obtained in the case of flat initial conditions. The contributions of twist-two and (renormalon-type) higher-twist operators of the Wilson operator product expansion are…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. V. Kotikov , G. Parente

In this paper t and x-evolutions of gluon distribution function from Dokshitzer-Gribov-Lipatov-Altarelli-Parisi(DGLAP) evolution equation in leading order(LO) at low-x, assuming the Regge behaviour of quark and gluon at this limit, are…

High Energy Physics - Phenomenology · Physics 2014-11-18 U. Jamil , J. K. Sarma

Generalized parton distributions describe the distribution of partons in the transverse plane. For transversely polarized quarks and/or nucleons, these impact parameter dependent parton distributions are not axially symmetric. These…

High Energy Physics - Phenomenology · Physics 2008-11-26 Matthias Burkardt

In our previous work we established a formalism which allows one to determine the small-$x$ asymptotics of any transverse momentum-dependent parton distribution function (TMD PDF) of the proton at small values of strong coupling. In this…

High Energy Physics - Phenomenology · Physics 2019-04-03 Yuri V. Kovchegov , Matthew D. Sievert

The generalized parton distributions, introduced nearly a decade ago, have emerged as a universal tool to describe hadrons in terms of quark and gluonic degrees of freedom. They combine the features of form factors, parton densities and…

High Energy Physics - Phenomenology · Physics 2009-09-29 A. V. Belitsky , A. V. Radyushkin

Using constituent quark model constraints we calculate the gluon and sea-quark content of pions solely in terms of their valence density (fixed by \pi N Drell-Yan data) and the known sea and gluon distributions of the nucleon, using the…

High Energy Physics - Phenomenology · Physics 2010-04-06 M. Gluck , E. Reya , I. Schienbein

Recent developments showed that hadron light-cone parton distributions could be directly extracted from spacelike correlators, known as quasi parton distributions, in the large hadron momentum limit. Unlike the normal light-cone parton…

High Energy Physics - Phenomenology · Physics 2017-01-04 Jiunn-Wei Chen , Xiangdong Ji , Jian-Hui Zhang