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Related papers: Proton structure from a light-front Hamiltonian

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New results about the electromagnetic form factors of the nucleon are obtained with a semirelativistic version of the hypercentral constituent quark model (hCQM) and a relativistic current. The complex structure of the constituent quarks is…

Nuclear Theory · Physics 2015-07-21 M. De Sanctis , M. M. Giannini , E. Santopinto , A. Vassallo

We investigate the electroweak form factors and semileptonic decay rates of mesons using the constituent quark model based on the light-front degrees of freedom. Our results demonstrate the broader applicability of light-front approach…

High Energy Physics - Phenomenology · Physics 2007-05-23 Chueng-Ryong Ji , Ho-Meoyng Choi

This work presents the first calculation in lattice QCD of three moments of spin-averaged and spin-polarized generalized parton distributions in the proton. It is shown that the slope of the associated generalized form factors decreases…

High Energy Physics - Lattice · Physics 2012-08-27 LHPC , SESAM Collaborations , : , Ph. Hagler , J. W. Negele , D. B. Renner , W. Schroers , Th. Lippert , K. Schilling

Continuing with our analysis of parton distributions in the nucleon, we extend our light-front quark model in order to obtain both the helicity independent and helicity dependent parton distributions, analytically matching the results of…

High Energy Physics - Phenomenology · Physics 2017-03-08 Thomas Gutsche , Valery E. Lyubovitskij , Ivan Schmidt

We investigate the internal structure of the ground ($1S$) and the first two radially excited ($2S,3S$) states of the pion within the light-front quark model. The valence Fock sector is described using pure harmonic-oscillator eigenstates…

High Energy Physics - Phenomenology · Physics 2026-01-13 Ashutosh Dwibedi , Satyajit Puhan , Sabyasachi Ghosh , Harleen Dahiya

We present a recent calculation of the gravitational form factors (GFFs) of proton using the light-front quark-diquark model constructed by the soft-wall AdS/QCD. The four GFFs $~A(Q^2)$ , $B(Q^2)$ , $C(Q^2)$ and $\bar{C}(Q^2)$ are…

High Energy Physics - Phenomenology · Physics 2021-08-10 Dipankar Chakrabarti , Chandan Mondal , Asmita Mukherjee , Sreeraj Nair , Xingbo Zhao

The $\rho$ meson gravitational form factors are studied based on a light-front constituent quark model which has been successfully employed to calculate its generalized parton distributions and some low-energy observables. The distributions…

High Energy Physics - Phenomenology · Physics 2020-05-20 Bao-Dong Sun , Yu-Bing Dong

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

The electromagnetic elastic form factors of pseudoscalar and vector mesons are analyzed for space-like momentum transfers in terms of relativistic quark models based on the Hamiltonian light-front formalism elaborated in different reference…

Nuclear Theory · Physics 2009-11-07 Silvano Simula

We discuss the recent experimental results on the ratio bertween the electric and magnetic proton form factors and how they can be described by the hypercentral Constituent Quark Model.

Nuclear Theory · Physics 2015-06-30 M. De Sanctis , M. M. Giannini , E. Santopinto , A. Vassallo

In this work, we perform a detailed study of transition form factors for axial-vector meson production via the two-photon fusion process $\gamma^* \gamma^* \to 1^{++}$, with space-like virtual photons in the initial state and a $P$-wave…

High Energy Physics - Phenomenology · Physics 2022-10-19 Izabela Babiarz , Roman Pasechnik , Wolfgang Schäfer , Antoni Szczurek

A new picture is given of generalized parton distributions probed in experiments in which the probe scale $Q^{2}$ and the momentum transfer $\DD^{2}$ are well separated. Application of this picture to the $Q^{2}$ dependence of the form…

High Energy Physics - Phenomenology · Physics 2015-06-25 John P. Ralston , Roman V. Buniy , Pankaj Jain

We present a quark-parton model to describe polarized and unpolarized nucleon structure functions. The twist-two matrix elements for the QCD evolution analysis of lepton-hadron scattering are calculated within a light-front covariant quark…

High Energy Physics - Phenomenology · Physics 2011-04-15 Marco Traini , Pietro Faccioli , Vicente Vento

Longitudinal and transverse parton distributions for pion and nucleon are calculated from hadron vertexes obtained by a study of form factors within relativistic quark models. The relevance of the one-gluon-exchange dominance at short range…

High Energy Physics - Phenomenology · Physics 2011-07-21 T. Frederico , E. Pace , B. Pasquini , G. Salmé

The deuteron electromagnetic form factors, $A(Q^2)$ and $B(Q^2)$, and the tensor polarization $T_{20}(Q^2)$, are unambiguously calculated within the front-form relativistic Hamiltonian dynamics, by using a novel current, built up from…

Nuclear Theory · Physics 2011-07-19 F. M. Lev , E. Pace , G. Salme`

We propose a phenomenological light-front wave function for hadrons with arbitrary twist-dimension (mesons, baryons and multiquark states), which gives the correct scaling behavior of structure functions (parton distributions) and form…

High Energy Physics - Phenomenology · Physics 2014-04-02 Thomas Gutsche , Valery E. Lyubovitskij , Ivan Schmidt , Alfredo Vega

The spin fractions and deep inelastic structure functions of the proton are analyzed using chiral field theory involving Goldstone bosons. A detailed comparison with recent chiral models sheds light on their successful description of the…

High Energy Physics - Phenomenology · Physics 2009-10-31 H. J. Weber

Light-Front Quantization -- Dirac's "Front Form" -- provides a physical, frame-independent formalism for hadron dynamics and structure. Observables such as structure functions, transverse momentum distributions, and distribution amplitudes…

High Energy Physics - Phenomenology · Physics 2015-12-22 Stanley J. Brodsky

We have evaluated nucleon and pion electromagnetic form factors using for the first time eigenfunctions of a light-front mass operator, reproducing a large set of energy levels, and constituent quark form factors in the one-body current.…

Nuclear Theory · Physics 2016-08-15 F. Cardarelli , E. Pace , G. Salmè , S. Simula

We investigate the twist-$3$ transverse-momentum-dependent parton distribution functions (TMDs) of the pion with basis light-front quantization. The twist-3 TMDs are not independent and can be decomposed into twist-$2$ and genuine twist-$3$…

High Energy Physics - Phenomenology · Physics 2023-04-12 Zhimin Zhu , Zhi Hu , Jiangshan Lan , Chandan Mondal , Xingbo Zhao , James P. Vary , BLFQ Collaboration