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Related papers: Nucleon form factors: the space-time connection

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We analyze the basic hard exclusive processes: \pi\gamma*\gamma - transition, pion and nucleon electromagnetic form factors, and discuss the analytic continuation of QCD formulas from the spacelike q^2<0 to the timelike region q^2 >0 of the…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. P. Bakulev , A. V. Radyushkin , N. G. Stefanis

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

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 the nucleon strange electromagnetic form factors using four lattice QCD ensembles with $N_f=2+1+1$ twisted mass clover-improved fermions and quark masses tuned to approximately their physical values. The four ensembles have…

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

Precise proton and neutron form factor measurements at Jefferson Lab, using spin observables, have recently made a significant contribution to the unraveling of the internal structure of the nucleon. Accurate experimental measurements of…

Nuclear Experiment · Physics 2015-06-02 V. Punjabi , C. F. Perdrisat , M. K. Jones , E. J. Brash , C. E. Carlson

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

The present-day experimental situation concerning nucleon form factors in the space-like region shows a substantial discrepancy between measurements via the Rosenbluth method and the recoil polarisation technique. More information about…

High Energy Physics - Phenomenology · Physics 2007-05-23 E. Nowak

The study of the electromagnetic form factors of the nucleon in both the space-like and time-like domains plays a key role for the understanding of the internal structure and dynamics of this basic building block of the matter. Form factors…

High Energy Physics - Experiment · Physics 2007-05-23 P. Rossi

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

We present a detailed study of the nucleon electromagnetic form factors in the spacelike region by combining three complementary approaches: two GPD-based contributions and a vector-meson exchange component. By fitting experimental data, we…

High Energy Physics - Phenomenology · Physics 2026-04-13 Hossein Vaziri , Mohammad Reza Shojaei , Pere Masjuan

By means of the 10-resonance unitary and analytic model of nucleon electromagnetic structure it is demonstrated that the JLab proton polarization data on the ratio $\mu_p G_{Ep}(Q^2)/G_{Mp}(Q^2)$ are consistent with all form factor…

High Energy Physics - Phenomenology · Physics 2007-08-02 A. Z. Dubnickova , S. Dubnicka

We compute the nucleon axial and induced pseudoscalar form factors using three ensembles of gauge configurations, generated with dynamical light quarks with mass tuned to approximately their physical value. One of the ensembles also…

We present the strange electromagnetic form factors of the nucleon using lattice QCD simulations with degenerate light, a strange, and a charm quark in the sea with masses tuned to their physical values. For the first time, the strange…

The electromagnetic form factors of the proton are obtained using a particular realization of QCD in the large $N_c$ limit (${QCD}_{\infty}$), which sums up the infinite number of zero-width resonances to yield an Euler's Beta function…

High Energy Physics - Phenomenology · Physics 2010-02-03 C. A. Dominguez , T. Thapedi

Results for the proton and neutron electric and magnetic form factors as well as the nucleon axial form factor are presented for constituent quark models, based on either one-gluon-exchange and Goldstone-boson-exchange dynamics. The…

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

We present a comprehensive analysis of the spacelike nucleon electromagnetic form factors and their flavor decomposition within the framework of light-front holographic QCD. We show that the inclusion of the higher Fock components $\ket…

High Energy Physics - Phenomenology · Physics 2017-02-03 Raza Sabbir Sufian , Guy F. de Téramond , Stanley J. Brodsky , Alexandre Deur , Hans Günter Dosch

We use the energy-momentum tensor (EMT) current to compute the EMT form factors of the nucleon in the framework of the light cone QCD sum rule formalism. In the calculations, we employ the most general form of the nucleon's interpolating…

High Energy Physics - Phenomenology · Physics 2020-03-18 K. Azizi , U. Ozdem

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

Lattice simulations of QCD have produced precise estimates for the masses of the lowest-lying hadrons which show excellent agreement with experiment. By contrast, lattice results for the vector and axial vector form factors of the nucleon…

High Energy Physics - Lattice · Physics 2011-09-23 B. B. Brandt , S. Capitani , M. Della Morte , D. Djukanovic , J. Gegelia , G. von Hippel , A. Juttner , B. Knippschild , H. B. Meyer , H. Wittig