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We present a combined next-to-leading order QCD analysis to data on both inclusive and semi-inclusive polarized deep inelastic scattering asymmetries. Performing NLO QCD global fits with different sets of observables, we evaluate the impact…

High Energy Physics - Phenomenology · Physics 2009-10-30 D. de Florian , O. Sampayo , R. Sassot

Analytical solutions for the non-singlet polarized parton distribution are obtained by solving the DGLAP equation by two analytical methods: Lagranges Method and Method of Characteristics.The relative merits of the two methods are discussed…

High Energy Physics - Phenomenology · Physics 2014-04-04 Neelakshi N. K. Borah , Dilip K. Choudhury , P. K. Sahariah

In this thesis we consider the polarized deep inelastic scattering in the region of low values of Bjorken variable, $x$. We formulate the evolution equations for the unintegrated parton distributions which include a complete resummation of…

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

We present the first simultaneous global QCD analysis of spin-dependent parton distribution functions alongside their spin-averaged counterparts and pion, kaon, and unidentified hadron fragmentation functions. This analysis includes all…

High Energy Physics - Phenomenology · Physics 2023-09-08 C. Cocuzza , W. Melnitchouk , A. Metz , N. Sato

We have made next to leading order QCD fit to the deep inelastic spin asymmetries on nucleons and we determined polarised quark and gluon densities. The functional form for such distributions was inspired by the Martin, Roberts and Stirling…

High Energy Physics - Phenomenology · Physics 2007-05-23 Stanislaw Tatur , Jan Bartelski , Miroslaw Kurzela

We calculated the polarized parton distributions in leading order approximation in QCD from valon model. Polarized structure function of the nucleon are analyzed in the polarized valon model in which a nucleon is assumed to be a bound state…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Atashbar Tehrani , Ali N. Khorramian

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

A method of obtaining parton distributions directly from data is revealed in this series. In the process, the first step would be developing appropriate matrix solutions of the evolution equations in $x$ space. A division into commuting and…

High Energy Physics - Phenomenology · Physics 2013-03-19 Mehrdad Goshtasbpour , Seyed Ali Shafiei

Analytic formulae are given for QCD corrections to the lepton spectra in decays of polarised up and down type heavy quarks. These formulae are much simpler than the published ones for the corrections to the spectra of charged leptons…

High Energy Physics - Phenomenology · Physics 2010-11-01 A. Czarnecki , M. Jeżabek

Renormalization group evolution equations describing the scale dependence of quantities in quantum chromodynamics (QCD) play a central role in the interpretation of experimental data. Arguably the most important evolution equations for…

High Energy Physics - Phenomenology · Physics 2022-10-20 Hao Chen , Max Jaarsma , Yibei Li , Ian Moult , Wouter J. Waalewijn , Hua Xing Zhu

We investigate the radiative quantum electrodynamic (QED) corrections to the lepton ($L=e, ~\mu $ and $\tau$) anomalous magnetic moment due to the contributions of diagrams with insertions of the photon vacuum polarisation operator…

High Energy Physics - Phenomenology · Physics 2023-10-19 O. P. Solovtsova , V. I. Lashkevich , L. P. Kaptari

We present an efficient numerical solution of the DGLAP equations for single and double parton distribution functions (PDFs and DPDs), based on the Chebyshev interpolation of these functions. For PDF evolution, our method allows for a…

High Energy Physics - Phenomenology · Physics 2019-06-25 Riccardo Nagar

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

Iterative solution of QED evolution equations for non-singlet electron structure functions is considered. Analytical expressions in the fourth and fifth orders are presented in terms of splitting functions. Relation to the existing…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. B. Arbuzov

In processes taking place at energies much higher than the weak scale, electroweak corrections can be taken into account by using electroweak evolution equations, that are analogous to the DGLAP equations in QCD. We show that weak isospin…

High Energy Physics - Phenomenology · Physics 2024-03-26 Paolo Ciafaloni , Giampaolo Co' , Dimitri Colferai , Denis Comelli

In this paper we use the experimental data to obtain the polarized parton distribution functions (PPDFs) in the LO and NLO approximations. The analysis is based on the Jacobi polynomials expansion of the polarized structure function (PSF).…

High Energy Physics - Phenomenology · Physics 2007-12-17 Ali N. Khorramian , S. Atashbar Tehrani

We evaluate nucleon four-point functions in the framework of lattice QCD in order to extract the first Mellin moment of double parton distributions (DPDs) in the unpolarized proton. In this first study, we employ an nf = 2 + 1 ensemble with…

High Energy Physics - Lattice · Physics 2021-09-24 Gunnar S. Bali , Markus Diehl , Benjamin Gläßle , Andreas Schäfer , Christian Zimmermann

Efficient algorithms for the solution of partial differential equations on parallel computers are often based on domain decomposition methods. Schwarz preconditioners combined with standard Krylov space solvers are widely used in this…

High Energy Physics - Lattice · Physics 2009-11-10 Martin Lüscher

We present a new NLO QCD analysis of the world data on inclusive polarized deep inelastic scattering. Comparing to our previous analysis: i) the values of g_A and a_8=3F-D are updated ii) the MRST'99 instead of the MRST'98 parametrization…

High Energy Physics - Phenomenology · Physics 2015-06-25 Elliot Leader , Aleksander V. Sidorov , Dimiter B. Stamenov

We investigate a numerical solution of the flavor-nonsinglet Altarelli-Parisi equation with next-to-leading-order $\alpha_s$ corrections by using Laguerre polynomials. Expanding a structure function (or a quark distribution) and a splitting…

High Energy Physics - Phenomenology · Physics 2014-11-17 R. Kobayashi , M. Konuma , S. Kumano