English
Related papers

Related papers: The Pion Form Factor in AdS/QCD

200 papers

We present a study of the flavor form factors in the framework of a hard-wall AdS/QCD model and compare with the available experimental data. We obtain the flavor form factors by decomposing the Dirac and Pauli form factors for the nucleons…

High Energy Physics - Phenomenology · Physics 2016-10-25 Chandan Mondal

The pion form factor is computed using quenched twisted mass QCD and the GMRES-DR matrix inverter. The momentum averaging procedure of Frezzotti and Rossi is used to remove leading lattice spacing artifacts, and numerical results for the…

High Energy Physics - Lattice · Physics 2009-11-10 Abdou M. Abdel-Rehim , Randy Lewis

The elastic and $\gamma \to \pi$ transition form factors of the pion along with its usual static observables are calculated within a light-front field approach to the constituent quark model. The focus of this exercise in a simple model is…

Nuclear Theory · Physics 2015-06-18 J. P. B. C. de Melo , B. El-Bennich , T. Frederico

Soft-wall models in AdS/QCD generally have dilaton and scalar fields that vary with the fifth-dimension coordinate. These fields can be parameterized to yield hadron mass spectra with linear radial trajectories and to incorporate…

High Energy Physics - Phenomenology · Physics 2010-06-01 J. I. Kapusta , T. Springer

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 report that the inclusion of dynamical spin effects in the pion holographic light-front wavefunction leads to a remarkable improvement in describing pion observables (pion mean charge radius, decay constant, spacelike electromagnetic…

High Energy Physics - Phenomenology · Physics 2017-12-04 Mohammad Ahmady , Farrukh Chishtie , Ruben Sandapen

We use light-cone QCD sum rules to calculate the pion-photon transition form factor, taking into account radiative corrections up to the next-to-next-to-leading order of perturbation theory. We compare the obtained predictions with all…

High Energy Physics - Phenomenology · Physics 2015-05-14 S. V. Mikhailov , N. G. Stefanis

We present an improved study of the electromagnetic form factors of the nucleon and of the Roper-nucleon transition using an extended version of the effective action of soft-wall AdS/QCD. We include novel contribution from additional…

High Energy Physics - Phenomenology · Physics 2018-03-21 Thomas Gutsche , Valery E. Lyubovitskij , Ivan Schmidt

We study consistently the pion's static observables and the elastic and \gamma*\gamma -> \pi^0 transition form factors within a light-front model. Consistency requires that all calculations are performed within a given model with the same…

Nuclear Theory · Physics 2013-01-30 B. El-Bennich , J. P. B. C. de Melo , T. Frederico

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

It may be possible to approximate the full pion wave function in light-front QCD using only $q \qbar$ and $q \qbar g$ Fock space components. Removing zero modes and using invariant-mass cutoffs that make a constituent approximation possible…

High Energy Physics - Phenomenology · Physics 2009-10-31 Robert J. Perry

We analyze the higher-twist effects and the SU(3)-flavour symmetry breaking in the correlation functions used to calculate form factors of pseudoscalar mesons in the QCD light-cone sum rule approach. It is shown that the Ward identities for…

High Energy Physics - Phenomenology · Physics 2011-09-13 Johan Bijnens , Alexander Khodjamirian

In this talk, results are presented of determinations of electromagnetic form factors of hadrons (pion, proton, and $\Delta(1236)$) in the framework of Dual-Large $N_c$ QCD (Dual-$QCD_\infty$). This framework improves considerably…

High Energy Physics - Phenomenology · Physics 2015-05-18 C. A. Dominguez

Chiral symmetry is an essential concept in understanding QCD at low energy. We treat the chiral condensate, which measures the spontaneous breaking of chiral symmetry, as a free parameter to investigate the effect of partially restored…

High Energy Physics - Phenomenology · Physics 2008-11-26 Youngman Kim , Hyun Kyu Lee

The vector form factor of the pion is calculated in the framework of chiral effective field theory with vector mesons included as dynamical degrees of freedom. To construct an effective field theory with a consistent power counting, the…

High Energy Physics - Phenomenology · Physics 2015-06-23 D. Djukanovic , J. Gegelia , A. Keller , S. Scherer , L. Tiator

We summarize recent progress in soft QCD modeling based on the set of Dyson--Schwinger equations truncated to ladder-rainbow level. We pay particular attention to electromagnetic elastic and transition form factors of the pion. This…

Nuclear Theory · Physics 2017-08-23 Peter C. Tandy

NNLO QCD corrections for the pion electromagnetic form factor at large momentum transfer have been recently performed in [Phys. Rev. Lett. 132, 201901 (2024); Phys. Rev. Lett. 134, 221901 (2025)], revealing that the NLO and NNLO…

High Energy Physics - Phenomenology · Physics 2025-12-29 Sheng-Quan Wang , Zuo-Fen Liao , Jian-Ming Shen , Hua Zhou , Jia-Wei Zhang , Jiang Yan , Xing-Gang Wu , Leonardo Di Giustino

Recent developments in the QCD description of the pion structure are reviewed. The CLEO pion-photon transition data analysis favors a distribution amplitude for the pion that is double-humped but endpoint-suppressed. After a short outline…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. P. Bakulev , S. V. Mikhailov , N. G. Stefanis

We consider the pion structure in the region of low and moderately high momentum transfers: at low $Q^2$, the pion is treated as a composite system of constituent quarks; at moderately high momentum transfers, $Q^2=10\div25\;GeV^2$, the…

High Energy Physics - Phenomenology · Physics 2009-10-28 V. Anisovich , D. Melikhov , V. Nikonov

We perform the potential analysis for the holographic Schwinger effect in a deformed $AdS_5$ model with conformal invariance broken by a background dilaton. We evaluate the static potential by analyzing the classical action of a string…

High Energy Physics - Theory · Physics 2021-02-03 Yue Ding , Zi-qiang Zhang