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Related papers: Timelike nucleon electromagnetic form factors: All…

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We investigate the nonmonotonic behavior observed in the time-like nucleon electromagnetic form factors. Using a phenomenological extending vector meson dominance model, where the ground states $\rho$ and $\omega$ and their excited states…

Nuclear Theory · Physics 2024-03-01 Bing Yan , Cheng Chen , Xia Li , Ju-Jun Xie

The electromagnetic form factors of the proton and the neutron in the timelike region are investigated. Electron-positron annihilation into antinucleon-nucleon ($\bar NN$) pairs is treated in distorted wave Born approximation, including the…

Nuclear Theory · Physics 2023-12-06 Qin-He Yang , Ling-Yun Dai , Di Guo , Johann Haidenbauer , Xian-Wei Kang , Ulf-G. Meißner

The electromagnetic form factors of the proton and the neutron in the timelike region are reviewed. In view of the forthcoming experimental projects devoted to investigate these observables, we present the current status of the field and we…

High Energy Physics - Experiment · Physics 2012-10-18 Achim Denig , Giovanni Salme`

The electromagnetic form factors $G_{\rm E}$ and $G_{\rm M}$ of the proton and neutron in the timelike region are extracted in a study of the processes $e^+ e^-\to \bar{p}p$ and $e^+ e^-\to \bar{n}n$. The reaction amplitude is evaluated…

Nuclear Theory · Physics 2024-04-22 Qin-He Yang , Di Guo , Ming-Yan Li , Ling-Yun Dai , Johann Haidenbauer , Ulf-G. Meißner

For the first time, a phenomenological analysis of the experimental electromagnetic form factors of the nucleon, both in the timelike and spacelike regions, is performed by taking into account the effects of nonvalence components in the…

High Energy Physics - Phenomenology · Physics 2009-02-16 J. P. B. C. de Melo , T. Frederico , E. Pace , S. Pisano , G. Salmè

Recent experimental data on space- and time-like form factors of the nucleon are analyzed in terms of a two-component model with a quark-like intrinsics structure and a meson cloud. A good overall agreement is found for all electromagnetic…

Nuclear Theory · Physics 2017-11-02 R. Bijker

The data on the proton form factors in the time-like region from the BaBar, BESIII and CMD-3 Collaborations are examined to have coherent pieces of information on the proton structure. Oscillations in the annihilation cross section,…

High Energy Physics - Phenomenology · Physics 2021-03-24 Egle Tomasi-Gustafsson , Andrea Bianconi , Simone Pacetti

We present an analysis of the recent near threshold BESIII data for the nucleon time-like effective form factors. The damped oscillation emerging from the subtraction of the dipole formula is treated in non-perturbative-QCD, making use of…

High Energy Physics - Phenomenology · Physics 2024-07-12 Francesco Rosini , Simone Pacetti , Olga Shekhovtsova , Egle Tomasi-Gustafsson

Elastic electromagnetic nucleon form factors have long provided vital information about the structure and composition of these most basic elements of nuclear physics. The form factors are a measurable and physical manifestation of the…

Nuclear Theory · Physics 2008-11-26 J. Arrington , C. D. Roberts , J. M. Zanotti

Based on the recently precise measurements of the electron-positron annihilation reactions into a neutron and anti-neutron pair by BESIII collaboration, the effective form factor of neutron was determined in the time like region, and it was…

High Energy Physics - Phenomenology · Physics 2022-07-13 An-Xin Dai , Zhong-Yi Li , Lei Chang , Ju-Jun Xie

An intriguing and elusive feature of the timelike hadron form factor is the possible presence of an imaginary part associated to rescattering processes. We find evidence of that in the recent and precise data on the proton timelike form…

Nuclear Theory · Physics 2015-06-17 Andrea Bianconi , Egle Tomasi-Gustafsson

Form factors are Lorentz invariant functions describing the internal structure of a system. In particular, they encode how physical properties like, e.g., charge, energy, momentum, and pressure are spatially distributed. While nucleon…

High Energy Physics - Phenomenology · Physics 2024-02-02 Cédric Lorcé

We present a combined analysis of the electromagnetic form factors of the nucleon in the space- and timelike regions using dispersion theory. Our framework provides a consistent description of the experimental data over the full range of…

High Energy Physics - Phenomenology · Physics 2022-02-16 Yong-Hui Lin , Hans-Werner Hammer , Ulf-G. Meißner

We examine isospin breaking in the nucleon wave functions due to the $u - d$ quark mass difference and the Coulomb interaction among the quarks, and their consequences on the nucleon electroweak form factors in a nonrelativistic constituent…

High Energy Physics - Phenomenology · Physics 2008-11-26 V. Dmitrasinovic , S. J. Pollock

Analyticity of nucleon form factors allows to derive sum rules which, using space-like and time-like data as input, can give unique information about behaviors in energy regions not experimentally accessible. Taking advantage from new…

High Energy Physics - Phenomenology · Physics 2011-09-28 S. Pacetti

We review the dispersion-theoretical analysis of the electromagnetic form factors of the nucleon. We emphasize in particular the role of unitarity and analyticity in the construction of the isoscalar and isovector spectral functions. We…

High Energy Physics - Phenomenology · Physics 2021-08-27 Yong-Hui Lin , Hans-Werner Hammer , Ulf-G. Meißner

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

The measurements of the nucleon electromagnetic form factors in the time-like region are reviewed. Several unexpected features deserving new high precision, high statistics measurements are emphasised.

High Energy Physics - Experiment · Physics 2007-05-23 Alessandro De Falco

Dispersion relations provide a powerful tool to describe the electromagnetic form factors of the nucleon both in the spacelike and timelike regions with constraints from unitarity and perturbative QCD. We give a brief introduction into…

High Energy Physics - Phenomenology · Physics 2014-11-17 H. -W. Hammer

We perform a global analysis of the experimental data of the electromagnetic nucleon form factors, in space-like and time-like regions. We give the expressions of the observables in annihilation processes, such as $p+\bar{p}\to \ell^+…

Nuclear Theory · Physics 2014-11-18 Egle Tomasi-Gustafsson , F. Lacroix , C. Duterte , G. I. Gakh
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