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Related papers: Pion form factor from an AdS deformed background

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The pion electromagnetic form factor is calculated at lower and higher momentum transfer in order to explore constituent quark models and the differences among those models. In particular, the light-front constituent quark model is utilized…

High Energy Physics - Phenomenology · Physics 2016-10-19 J. P. B. C. de Melo , Rômulo Moreira Moita , Kazuo Tsushima

The pion electromagnetic form factor is calculated in the space- and time-like regions from -10 $(GeV/c)^2$ up to 10 $(GeV/c)^2$, within a front-form model. The dressed photon vertex where a photon decays in a quark-antiquark pair is…

High Energy Physics - Phenomenology · Physics 2009-11-10 J. P. B. C. de Melo , T. Frederico , E. Pace , G. Salme`

We account for dynamical spin effects in the holographic light-front wavefunction of the pion in order to predict its mean charge radius, decay constant, spacelike electromagnetic form factor, twist-2 Distribution Amplitude and the…

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

We study the decays $\pi^{+}\to l^{+}\nu_{l}$ in the presence of a background electromagnetic plane wave with circular polarization. We find that, in the presence of this background, the number of hadronic form factors required to describe…

High Energy Physics - Phenomenology · Physics 2025-09-25 D. Gomez Dumm , S. Noguera , N. N. Scoccola

We extend a recent numerical calculation of the pion electromagnetic form factor F_\pi (Q^2) in holographic QCD to study two important issues regarding the behavior of fields in the bulk. First, we show that using a chiral symmetry-breaking…

High Energy Physics - Phenomenology · Physics 2008-11-26 Herry J. Kwee , Richard F. Lebed

We present a lattice calculation of the electromagnetic form factor of the pion obtained using the tree-level Symanzik improved gauge action with two flavors of dynamical twisted Wilson quarks. The simulated pion masses range approximately…

High Energy Physics - Lattice · Physics 2009-11-06 R. Frezzotti , V. Lubicz , S. Simula

We study a model-independent parameterization of the vector pion form factor that arises from the constraints of analyticity and unitarity. Our description should be suitable up to s^(1/2) ~ 1.2 GeV and allows a model-independent…

High Energy Physics - Phenomenology · Physics 2009-11-07 A. Pich , J. Portoles

The H(e,e'pi+)n cross section was measured at four-momentum transfers of Q2=1.60 and 2.45 GeV2 at an invariant mass of the photon nucleon system of W=2.22 GeV. The charged pion form factor (F_pi) was extracted from the data by comparing the…

Separated longitudinal and transverse structure functions for the reaction 1H(e,eprime pi+)n were measured in the momentum transfer region Q2=0.6-1.6 (GeV/c)**2 at a value of the invariant mass W=1.95 GeV. New values for the pion charge…

Nuclear Experiment · Physics 2009-04-15 J. Volmer

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

We study the pion electromagnetic form factor in the modulus squared dispersion relation, and do the model independent extraction of the most important nonperturbative parameters in pion light-cone distribution amplitude. The motivation of…

High Energy Physics - Phenomenology · Physics 2023-07-26 Jian Chai , Shan Cheng , Jun Hua

The light-front approach is applied to calculate the electromagnetic current for quark-antiquark bound states for the pion. The pion electromagnetic form factor is obtnaide from the "+" and "-" components of the electromagnetic current in…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. P. B. C. de Melo

We present a lattice calculation of the vector form factor of the pion for two flavours of non-perturbatively O(a) improved Wilson fermions. For the measurements we utilise the CLS ensembles which include various lattice spacings and pion…

High Energy Physics - Lattice · Physics 2011-09-02 Bastian B. Brandt , Andreas Juttner , Hartmut Wittig

Within the framework provided by quantum chromodynamics's Schwinger-Dyson equations (SDEs), the pion's electromagnetic form factor is computed using solutions of the Bethe-Salpeter equation (BSE) that have finite spacial momentum, and…

High Energy Physics - Phenomenology · Physics 2024-02-27 Shaoyang Jia , Ian Cloët

Pion transition form factor for the process $\gamma*\gamma*\to \pi^0$ at space-like values of photon momenta is calculated within the effective quark-meson model with the interaction induced by instanton exchange. The leading and…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. E. Dorokhov

We present a comprehensive study of the electromagnetic form factor, the decay constant and the mass of the pion computed in lattice QCD with two degenerate O(a)-improved Wilson quarks at three different lattice spacings in the range…

High Energy Physics - Lattice · Physics 2015-06-16 Bastian B. Brandt , Andreas Juttner , Hartmut Wittig

We propose an extension of the hard-wall AdS/QCD model by including the Chern-Simons term required to reproduce the chiral anomaly of QCD. In the framework of this holographic model, we study the vertex function F_{\pi \gamma^*…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. R. Grigoryan , A. V. Radyushkin

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

We obtain the distribution amplitude (DA) of the pion from its light-front wave functions in the basis light-front quantization framework. This light-front wave function of the pion is given by the lowest eigenvector of a light-front…

High Energy Physics - Phenomenology · Physics 2021-11-24 Chandan Mondal , Sreeraj Nair , Shaoyang Jia , Xingbo Zhao , James P. Vary

The electromagnetic form factor of the pion is obtained using a particular realization of QCD in the large $N_c$ limit, which sums up the infinite number of zero-width resonances to yield an Euler's Beta function of the Veneziano type. This…

High Energy Physics - Phenomenology · Physics 2009-11-07 C. A. Dominguez