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Related papers: Evaluation of the Nucleon Helicity Flip Form Facto…

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We provide a complete calculation of all leading nucleon form factors at large momentum transfer and in single gauge boson exchange approximation. In order to evaluate the required nucleon transition probability matrix elements, we combine…

High Energy Physics - Phenomenology · Physics 2011-11-04 Thorsten Sachs , Patrick Sturm

We identify quark and gluon helicity-flip distributions defined between nucleon states of unequal momenta. The evolution of these distributions with change of renormalization scale is calculated in the leading-logarithmic approximation. The…

High Energy Physics - Phenomenology · Physics 2009-10-31 Pervez Hoodbhoy , Xiangdong Ji

We compare a recent lattice determination of the nucleon distribution amplitudes with other approaches and models. We study the nucleon distribution amplitudes up to twist 6 in next-to leading conformal spin and we also investigate…

High Energy Physics - Phenomenology · Physics 2009-07-30 Alexander Lenz , Meinulf Göckeler , Thomas Kaltenbrunner , Nikolaus Warkentin

We give a brief overview of the General Parton Distributions(GPDs), including their properties, connections to conventional quantities, and relationships to physical observables. We also perform a systematic analysis on the non-forward…

High Energy Physics - Phenomenology · Physics 2007-05-23 Zhang Chen

We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer $Q^2$. It is shown that the leading two-photon exchange amplitude behaves as $1/Q^4$ relative to the one-photon amplitude, and…

High Energy Physics - Phenomenology · Physics 2009-09-02 Nikolai Kivel , Marc Vanderhaeghen

We derive light-cone sum rules for the electromagnetic nucleon form factors including the next-to-leading-order corrections for the contribution of twist-three and twist-four operators and a consistent treatment of the nucleon mass…

High Energy Physics - Phenomenology · Physics 2013-12-16 I. V. Anikin , V. M. Braun , N. Offen

We perform a systematic analysis on the off-forward matrix elements of the twist-two quark and gluon helicity-flip operators. By matching the allowed quantum numbers and their crossing channel counterparts (a method developed by Ji &…

High Energy Physics - Phenomenology · Physics 2009-11-10 Zhang Chen , Xiangdong Ji

We calculated two--photon exchange effects for elastic electron--proton scattering at high momentum transfers. The corresponding nucleon Compton amplitude is defined by two space--like virtual photons that appear to have significant…

High Energy Physics - Phenomenology · Physics 2017-08-23 Andrei Afanasev , Igor Akushevich , N. P. Merenkov

A two-dimensional Fourier transform of hadron form factors allows to determine their charge density in transverse space. We show that this method can be applied to any virtual photon induced transition, such as \gamma *(q)+N -> \pi N. Only…

High Energy Physics - Phenomenology · Physics 2011-06-13 Paul Hoyer , Samu Kurki

Using the helicity amplitudes formalism, we study deeply virtual exclusive electron photo-production off an unpolarized nucleon target, $ep \rightarrow e' p' \gamma$, through a range of kinematics both in the fixed target setting with…

High Energy Physics - Phenomenology · Physics 2021-11-23 Brandon Kriesten , Simonetta Liuti

We present a unified description of elastic and transition form factors involving the nucleon and its resonances; in particular, the $N(1440)$, $\Delta(1232)$ and $\Delta(1600)$. We compare predictions made using a framework built upon a…

Nuclear Theory · Physics 2020-08-26 J. Segovia , C. Chen , Z. -F. Cui , Y. Lu , C. D. Roberts

We calculate the two-photon exchange corrections to electron-proton scattering with nucleon and $\Delta$ intermediate states. The results show a dependence on the elastic nucleon and nucleon-$\Delta$-transition form factors used as input…

High Energy Physics - Phenomenology · Physics 2015-01-29 I. T. Lorenz , Ulf-G. Meißner , H. -W. Hammer , Y. -B. Dong

We propose possible methods to measure the nucleon electromagnetic form factors in presence of two-photon exchange. Using a general parametrization of the spin structure of the matrix element for elastic $eN$-scattering, in terms of three…

Nuclear Theory · Physics 2009-11-10 M. P. Rekalo , E. Tomasi-Gustafsson

We introduce twist-two quark interference fragmentation functions in helicity density matrix formalism and study their physical implications. We show how the nucleon's transversity distribution can be probed through the final state…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. L. Jaffe , Xuemin Jin , Jian Tang

We computed twist-4 part of the photon spin-flip amplitude in deeply virtual Compton scattering on a nucleon in the Wandzura-Wilczek approximation. We found a factorizable contribution, which arises from photon scattering on quarks with…

High Energy Physics - Phenomenology · Physics 2009-01-07 N. Kivel , L. Mankiewicz

A workable basis of quark configurations $s^3$, $s^2p$ and $sp^2$ at light front has been constructed to describe the high-$Q^2$ behavior of transition form factors and helicity amplitudes in the electroproduction of the lightest nucleon…

High Energy Physics - Phenomenology · Physics 2019-11-20 Igor T. Obukhovsky , Amand Faessler , Dimitry K. Fedorov , Thomas Gutsche , Valery E. Lyubovitskij

We extract the isovector tensor nucleon form factors, which play an important role in understanding the transverse spin structure of the nucleon when related to the quark helicity-flip generalized parton distributions via their first…

High Energy Physics - Phenomenology · Physics 2011-10-10 Guray Erkol , Altug Ozpineci

The three-dimensional structure of nucleons (protons and neutrons) is embedded in so-called generalized parton distributions, which are accessible from deeply virtual Compton scattering. In this process, a high energy electron is scattered…

In this work, we report a novel technique in lattice QCD for studying the high momentum-transfer region of nucleon form factors. These calculations could give important theoretical input to experiments, such as those of JLab's 12-GeV…

High Energy Physics - Lattice · Physics 2010-05-06 Huey-Wen Lin , Saul D. Cohen , Robert G. Edwards , Kostas Orginos , David G. Richards

We perform a perturbative QCD analysis of the gravitational form factors (GFFs) of nucleon at large momentum transfer. We derive the explicit factorization formula of the GFFs in terms of twist-3 and twist-4 light-cone distribution…

High Energy Physics - Phenomenology · Physics 2022-10-26 Xuan-Bo Tong , Jian-Ping Ma , Feng Yuan
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