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Related papers: Polarized Parton Distributiions and Light-Front Dy…

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We relate ordinary and skewed parton distributions to soft overlap contributions to elastic form factors and large angle Compton scattering, using light-cone wave functions in a Fock state expansion of the nucleon. With a simple ansatz for…

High Energy Physics - Phenomenology · Physics 2011-09-13 M. Diehl , T. Feldmann , R. Jakob , P. Kroll

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 present the generalized parton distributions (GPDs) for the valence quarks of the pion and the kaon in both momentum space and position space within the basis light-front quantization framework. These GPDs are obtained from the…

High Energy Physics - Phenomenology · Physics 2021-12-16 Lekha Adhikari , Chandan Mondal , Sreeraj Nair , Siqi Xu , Shaoyang Jia , Xingbo Zhao , James P. Vary

Light-Front Quantization provides a physical, frame-independent formalism for hadron dynamics and structure. Observables such as structure functions, transverse momentum distributions, and distribution amplitudes are defined from the…

High Energy Physics - Phenomenology · Physics 2016-04-20 Stanley J. Brodsky

We present a systematic study of the proton spin structure in terms of measurable parton distributions. For a transversely-polarizedproton, we derive a polarization sum rule from the leading generalized parton distributions appearing in…

High Energy Physics - Phenomenology · Physics 2012-10-18 Xiangdong Ji , Xiaonu Xiong , Feng Yuan

Light strongly interacting supersymmetric particles may be treated as partonic constituents of nucleons in high energy scattering processes. We construct parton distribution functions for protons in which a light gluino is included along…

High Energy Physics - Phenomenology · Physics 2008-11-26 Edmond L. Berger , Pavel M. Nadolsky , Fredrick I. Olness , Jon Pumplin

Spin-dependent parton distributions in the polarized virtual photon are investigated in QCD up to the next-to-leading order (NLO). In the case $\Lambda^2 \ll P^2 \ll Q^2$, where $-Q^2$ ($-P^2$) is the mass squared of the probe (target)…

High Energy Physics - Phenomenology · Physics 2009-10-31 Ken Sasaki , Tsuneo Uematsu

At large N_c the nucleon can be viewed as a soliton of the effective chiral lagrangian. This picture of nucleons allows a consistent nonperturbative calculation of the leading-twist parton distributions at a low normalization point. We…

High Energy Physics - Phenomenology · Physics 2009-10-28 P. V. Pobylitsa , M. V. Polyakov

We present results on the quark unpolarized, helicity and transversity parton distributions functions of the nucleon. We use the quasi-parton distribution approach within the lattice QCD framework and perform the computation using an…

High Energy Physics - Lattice · Physics 2021-09-22 Constantia Alexandrou , Martha Constantinou , Kyriakos Hadjiyiannakou , Karl Jansen , Floriano Manigrasso

Generalized parton distributions provide information on the longitudinal and transverse distribution of partons in the fast moving nucleon. Furthermore, they contain information on the spin structure of the nucleon. First results of a…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Göckeler , T. R. Hemmert , R. Horsley , D. Pleiter , P. E. L. Rakow , A. Schäfer , G. Schierholz , W. Schroers

Using ideas from Light Front Holography, we discuss the calculation of hadronic properties. In this talk I will pay special attention to hadronic masses and the nucleon helicity-independent generalized parton distributions of quarks in the…

High Energy Physics - Phenomenology · Physics 2015-05-28 Alfredo Vega , Ivan Schmidt , Thomas Gutsche , Valery E. Lyubovitskij

The calculation of hadronic polarizability contribution of the nucleus to hyperfine structure of muonic hydrogen and helium is carried out within the unitary isobar model and experimental data on the polarized structure functions of deep…

High Energy Physics - Phenomenology · Physics 2017-11-03 A. V. Eskin , A. P. Martynenko , E. N. Elekina

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 perform a global leading-order QCD fit to recent polarized structure function data in order to extract a consistent set of spin-dependent parton distributions. Assuming that there is no significant intrinsic polarization of the quark…

High Energy Physics - Phenomenology · Physics 2007-05-23 T. Gehrmann , W. J. Stirling

We develop simple analytic representations of the polarized quark and gluon distributions in the nucleon at low $Q^2$ which incorporate general constraints obtained from the requirements of color coherence of gluon couplings at $x \sim 0$…

High Energy Physics - Phenomenology · Physics 2009-09-25 Stanley J. Brodsky , Matthias Burkardt , Ivan Schmidt

Significant differences between transverse and longitudinal polarized parton distributions are found at low energies within a light-front covariant quark model of the nucleon. These differences are due to relativistic spin effects…

High Energy Physics - Phenomenology · Physics 2009-10-31 F. Cano , P. Faccioli , M. Traini

We discuss some recent developments concerning the nucleon's helicity parton distribution functions: New preliminary data from jet production at RHIC suggest for the first time a non-vanishing polarization of gluons in the nucleon. SIDIS…

High Energy Physics - Phenomenology · Physics 2015-06-03 D. de Florian , R. Sassot , M. Stratmann , W. Vogelsang

Results for the proton and neutron electric and magnetic form factors as well asthe nucleon axial and induced pseudoscalar form factors are presented for the chiral constituent quark model based on Goldstone-boson-exchange dynamics. The…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Boffi , L. Ya. Glozman , W. Klink , W. Plessas , M. Radici , R. F. Wagenbrunn

We study the covariant version of the quark-parton model, in which the general rules of the angular momentum composition are accurately taken into account. We demonstrate how these rules affect the relativistic interplay between the quark…

High Energy Physics - Phenomenology · Physics 2014-04-07 Petr Zavada

We determine the quark distributions and structure functions for both unpolarized and polarized DIS of leptons on nucleons and nuclei. The scalar and vector mean fields in the nucleus modify the motion of the quarks inside the nucleons. By…

Nuclear Theory · Physics 2008-11-26 W. Bentz , I. C. Cloët , T. Ito , A. W. Thomas , K. Yazaki