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Related papers: Determining the Meson Cloud Contribution of Nucleo…

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The nucleon isovector electromagnetic form factors are calculated up to next-to-next-to-leading order by combining relativistic chiral perturbation theory (ChPT) of pion, nucleon, and $\Delta$(1232) with dispersion theory. We specifically…

High Energy Physics - Phenomenology · Physics 2023-12-18 Fernando Alvarado , Di An , Luis Alvarez-Ruso , Stefan Leupold

Models based on $SU(6)$ symmetry breaking and large $N_c$ limit provide relations between the pion cloud contributions to the $\gamma^\ast N \to \Delta(1232)$ quadrupole form factors, electric ($G_E$) and Coulomb ($G_C$), and the neutron…

High Energy Physics - Phenomenology · Physics 2019-03-11 G. Ramalho

Pion-nucleon elastic scattering in the dominant $P_{33}$ channel is examined in the model in which the interaction is of the form $\pi + N\leftrightarrow N, \Delta(1232)$. New expressions are found for the elastic pion-nucleon scattering…

Nuclear Theory · Physics 2014-11-18 D. J. Ernst

Recent experimental data on space-like and time-like form factors of the nucleon are reviewed in light of a model of the nucleon with an intrinsic (quark-like) structure and a meson cloud. The analysis points to the astonishing result that…

Nuclear Theory · Physics 2011-08-17 F. Iachello

Experimental observables of the elastic eD-scattering in the region of intermediate energies are discussed. We offer the analysis of the available experimental data, which reproduces the results of the calculations with popular…

High Energy Physics - Phenomenology · Physics 2009-09-25 A. P. Kobushkin , A. I. Syamtomov

A simple statistical model in terms of light-front kinematic variables is used to explain the nuclear EMC effect in the range $x \in [0.2,~0.7]$, which was constructed by us previously to calculate the parton distribution functions (PDFs)…

Nuclear Theory · Physics 2010-11-02 Yunhua Zhang , Lijing Shao , Bo-Qiang Ma

We have evaluated the Drell-Yan cross section in nuclei paying special attention to the meson cloud contribution from pion and rho-meson, for which an accurate calculation using the meson nuclear spectral functions is used. Similarly, the…

Nuclear Theory · Physics 2009-10-30 E. Marco , E. Oset

The electromagnetic form factors provide important hints for the internal structure of the nucleon and continue to be of major interest for experimentalists. For an intermediate range of momentum transfers the form factors can be calculated…

We present selected results from a calculation of meson and nucleon observables in a Green-function approach. A rainbow-ladder truncation of QCD's Dyson-Schwinger equations is used to solve the respective meson, diquark and quark-diquark…

High Energy Physics - Phenomenology · Physics 2009-06-25 Gernot Eichmann , Reinhard Alkofer , Andreas Krassnigg , Diana Nicmorus

We determine the nucleon electromagnetic form factors and their uncertainties from world electron scattering data. The analysis incorporates two-photon exchange corrections, constraints on the low-Q2 and high-Q2 behavior, and additional…

Nuclear Experiment · Physics 2017-12-12 Zhihong Ye , John Arrington , Richard J. Hill , Gabriel Lee

We update a recent dispersion--theoretical fit to the nucleon electromagnetic form factors by including the existing data in the time--like region. We show that while the time--like data for the proton can be described consistently with the…

High Energy Physics - Phenomenology · Physics 2009-10-28 H. -W. Hammer , Ulf-G. Meißner , D. Drechsel

A joint fit to neutrino-nucleon scattering and pion electroproduction data is performed to evaluate the nucleon axial form factor in the two-component model consisting of a three-quark intrinsic structure surrounded by a meson cloud.…

High Energy Physics - Phenomenology · Physics 2021-04-28 G. D. Megias , S. Bolognesi , M. B. Barbaro , E. Tomasi-Gustafsson

The recent investigation on various form factors of the nucleon is reviewed in the framework of the SU(3) chiral quark-soliton model. The results for the electromagnetic and scalar form factors are in remarkable agreement with experimental…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hyun-Chul Kim

We use the available information on the ratio between the electric and magnetic proton form factors coming from recently published space-like data and from the few available time-like data. We apply a dispersive procedure on these data to…

High Energy Physics - Phenomenology · Physics 2009-01-07 R. Baldini , C. Bini , P. Gauzzi , M. Mirazita , M. Negrini , S. Pacetti

Meson decays are considered within the constituent quark model, making use of the dispersion formulation of the model: Starting with spacelike momentum transfers $q$, meson transition form factors are expressed as relativistic invariant…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Melikhov

Parton convolution models have been used extensively in describing the sea quarks in the nucleon and explaining quark distributions in nuclei (the EMC effect). From effective field theory point of view, we construct the parton convolution…

High Energy Physics - Phenomenology · Physics 2009-11-07 Jiunn-Wei Chen , Xiangdong Ji

The structure of the nucleon and the first radial excitation of the nucleon, the Roper, $N(1440)$, is studied within the formalism of Light-Front holography. The nucleon elastic form factors and $\gamma^\ast N \to N(1440)$ transition form…

High Energy Physics - Phenomenology · Physics 2018-03-07 G. Ramalho , D. Melnikov

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

The contribution of the box and crossed two-pion-exchange diagrams to proton-proton scattering at 90$^{\circ}_{c.m.}$ is calculated in the laboratory momentum range up to 12 GeV/c. Relativistic form factors related to the nucleon and pion…

Nuclear Theory · Physics 2008-11-26 W. R. Gibbs , B. Loiseau

The reactions of electron-positron to nucleon-antinucleon pair at energy threshold are studied in a non-perturbative quark model. The puzzling experimental result that the ratio of the cross section of electron-positron to proton-antiproton…

High Energy Physics - Phenomenology · Physics 2009-07-03 Y. Yan , K. Khosonthongkee , C. Kobdaj , P. Suebka