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Related papers: The pion electromagnetic form-factor in a QCD-insp…

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We present a brief survey of some results on electroweak properties of composite systems that are obtained in the frameworks of our version of the instant form of relativistic quantum mechanics (RQM). Our approach describes well the $\pi$-…

High Energy Physics - Phenomenology · Physics 2017-01-17 A. F. Krutov , R. G. Polezhaev , V. E. Troitsky

Almost 50 years after the discovery of gluons & quarks, we are only just beginning to understand how QCD builds the basic bricks for nuclei: neutrons, protons, and the pions that bind them. QCD is characterised by two emergent phenomena:…

Nuclear Theory · Physics 2016-06-22 Tanja Horn , Craig D. Roberts

The kaon electromagnetic form factor is calculated within a light-front constituent quark model (LFCQM). The electromagnetic components of the current are extracted from the Feynman triangle diagram within the light-front approach. We also…

High Energy Physics - Phenomenology · Physics 2015-06-11 Edson O. da Silva , J. P. B. C. de Melo , Victo S. Filho , Bruno El-Bennich

The space-like electromagnetic form factor is expressed in terms of the overlap integral of the initial and final meson wave functions written as Lorentz covariant distributions of internal momenta. The meson constituents are assumed to be…

High Energy Physics - Phenomenology · Physics 2007-05-23 L. Micu

We present results of a calculation of the electromagnetic pion form factor within the framework of QCD Sum Rules with nonlocal condensates, using a perturbative spectral density which includes $O(\alpha_s)$ contributions.

High Energy Physics - Phenomenology · Physics 2014-11-18 Alexander P. Bakulev , A. V. Pimikov , N. G. Stefanis

We analyze the electromagnetic pion and kaon form factor by including radiative and higher-twist effects within the framework of resummed pQCD in the space-like region. We focus on the transition from the perturbative to non-perturbative…

High Energy Physics - Phenomenology · Physics 2009-03-02 Udit Raha , Andreas Aste

We obtain the light meson mass spectroscopy from the light-front quantum chromodynamics (QCD) Hamiltonian, determined for their constituent quark-antiquark and quark-antiquark-gluon Fock components, together with a three-dimensional…

High Energy Physics - Phenomenology · Physics 2022-01-17 Jiangshan Lan , Kaiyu Fu , Chandan Mondal , Xingbo Zhao , james P. Vary

We consider a model with $\rho\pi\pi$, $\rho KK$, and gauge-invariant $\rho\gamma$ couplings and obtain the pion form factor $F_\pi$ at timelike momentum transfers by resummation of pion and kaon loops. We use a dispersion representation…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Melikhov , O. Nachtmann , T. Paulus

The electric dipole form factor of the nucleon stemming from the QCD $\bar{\theta}$ term is calculated in chiral perturbation theory in leading order. To this order, the form factor originates from the pion cloud. Its momentum-dependence is…

Nuclear Theory · Physics 2009-11-11 W. H. Hockings , U. van Kolck

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

The pion electromagnetic form factor is calculated within the QCD light-cone sum rule method and using a renormalon model for the higher twist distribution amplitudes (DAs). The theoretical predictions are compared with the experimental…

High Energy Physics - Phenomenology · Physics 2009-11-11 S. S. Agaev

The suggestion of momentum dependence in the amplitude for rho-omega mixing has generated concern over related implications for vector meson dominance and the photon-rho coupling. We discuss two established representations of vector meson…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. B. O'Connell , B. C. Pearce , A. W. Thomas , A. G. Williams

The $\gamma^\ast \gamma \to \pi^0$ transition form factor, $G(Q^2)$, is computed on the entire domain of spacelike momenta using a continuum approach to the two valence-body bound-state problem in relativistic quantum field theory: the…

We review the current status of rho-omega mixing and discuss its implication for our understanding of charge-symmetry breaking. In order to place this work in context we also review the photon-hadron coupling within the framework of vector…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. B. O'Connell , B. C. Pearce , A. W. Thomas , A. G. Williams

We compute the electromagnetic form factor of the pion using non-perturbatively O(a) improved Wilson fermions. The calculations are done for a wide range of pion masses and lattice spacings. We check for finite size effects by repeating…

Detailed predictions for the scaled pion-photon transition form factor are given, derived with the method of light-cone sum rules and using pion distribution amplitudes with two and three Gegenbauer coefficients obtained from QCD sum rules…

High Energy Physics - Phenomenology · Physics 2014-03-03 S. V. Mikhailov , A. V. Pimikov , N. G. Stefanis

The transition form factor, decay width and charge form factor of pion are calculated within the model of induced nonlocal quark currents based on the assumption that the nonperturbative QCD vacuum can be characterized by a homogeneous…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ja. V. Burdanov , G. V. Efimov , S. N. Nedelko

We compute the Form Factors of both neutral and charged pion using a non-perturbative running of the strong coupling constant $\alpha_s$ obtained using a double-dilaton Holographic QCD model. These form factors remain poorly understood in…

High Energy Physics - Phenomenology · Physics 2026-04-13 Héctor Cancio , Pere Masjuan

In this work, we investigate the time-like pion form factor from lattice QCD in the isosymmetric limit, a quantity that plays an important role in understanding hadron physics with substantial phenomenological applications. This observable…

High Energy Physics - Lattice · Physics 2026-03-05 Gabriele Morandi , Mattia Bruno , Francesca Argia Bresciani , Christoph Lehner , Julian Parrino

We study the pion electromagnetic and $\gamma^* + \pi^0 \to \gamma$ transition form factors at intermediate momentum transfer. We calculate soft, nonperturbative corrections to the leading perturbative amplitudes which arise from the $q\bar…

High Energy Physics - Phenomenology · Physics 2010-03-04 A. Szczepaniak , A. G. Williams