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Related papers: Pion Form Factor in the NLC QCD SR approach

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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 present detailed numerical results for the pion space-like electromagnetic form factor obtained within a recently proposed model of the pion electromagnetic current in a confining light-front QCD-inspired model. The model incorporates…

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

We describe the present status of the pion distribution amplitude (DA) as it originates from several sources: (i) a nonperturbative approach based on QCD sum rules with nonlocal condensates, (ii) an $O(\alpha_s)$ QCD analysis of the CLEO…

High Energy Physics - Phenomenology · Physics 2009-04-17 A. P. Bakulev , S. V. Mikhailov , A. V. Pimikov , N. G. Stefanis

The pion form factor is calculated using quenched twisted mass QCD with beta=6.0 and maximal twisting angle omega=pi/2. Two pion masses and several values of momentum transfer are considered. The momentum averaging procedure of Frezzotti…

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

The holographic QCD prediction for the pion distribution amplitude (DA) $\phi_{hol}(u)$ is used to compute the pion spacelike electromagnetic form factor $F_{\pi}(Q^2)$ within the QCD light-cone sum rule method. In calculations the pion's…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. S. Agaev , M. A. Gomshi Nobary

We calculate the electromagnetic form factor of the pion in lattice gauge theory. The non-perturbatively improved Sheikoleslami-Wohlert lattice action is used together with the O(a) improved current. The form factor is compared to results…

High Energy Physics - Lattice · Physics 2009-11-10 J. van der Heide , J. H. Koch , E. Laermann , M. Lutterot

We calculate the leading twist valence quark distribution in the pion in the framework of QCD sum rules with nonlocal condensates. Particular attention has been paid to the correct account for the bilocal power corrections.

High Energy Physics - Phenomenology · Physics 2009-10-28 A. V. Belitsky

We present the current status of our lattice calculation of the electromagnetic form factor of the pion with two flavours of non-perturbatively O(a)-improved Wilson fermions. Using twisted boundary conditions and stochastic sources we…

High Energy Physics - Lattice · Physics 2013-01-17 Bastian B. Brandt , Andreas Juttner , Hartmut Wittig

The pion and kaon electromagnetic form factors $F_M(Q^2)$ are calculated at the leading order of pQCD using the running coupling constant method. In calculations the leading and next-to-leading order terms in $\alpha_S((1-x)(1-y)Q^2)$…

High Energy Physics - Phenomenology · Physics 2009-10-31 Shahin S. Agaev

We recalculate the pion electromagnetic form factor based on the perturbative QCD formalism that includes the Sudakov resummation. We take into account the evolution of the pion wave function in $b$, which represents the transverse extent…

High Energy Physics - Phenomenology · Physics 2007-05-23 David Tung , Hsiang-nan Li

We discuss a constraint of conformal symmetry in the analysis of the pion form factor. The usual power-law behavior of the form factor obtained in the perturbative QCD analysis can also be attained by taking negligible quark masses in the…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. -M. Choi , C. -R. Ji

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 calculate the electromagnetic form factor of the pion in quenched lattice QCD. The non-perturbatively improved Sheikoleslami-Wohlert lattice action is used together with the consistently O(a) improved current. We calculate the pion form…

High Energy Physics - Lattice · Physics 2009-11-10 J. van der Heide , J. H. Koch , E. Laermann

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

We consider the pion-photon transition form factor at low to intermediate spacelike momenta within the theoretical framework of light-cone sum rules. We derive predictions which take into account all currently known contributions stemming…

High Energy Physics - Phenomenology · Physics 2017-03-24 S. V. Mikhailov , A. V. Pimikov , N. G. Stefanis

We discuss the evaluation of the transition form factor (TFF) $F^{\gamma*\gamma\pi^0}(Q^2)$ by means of QCD theory and by state-space reconstruction from topological data analysis. We first calculate this quantity in terms of quark-gluon…

High Energy Physics - Phenomenology · Physics 2019-06-21 N. G. Stefanis

We present an investigation of the electromagnetic pion form factor, $F_\pi(Q^2)$, at small values of the four-momentum transfer $Q^2$ ($\lesssim 0.25$ GeV$^2$), based on the gauge configurations generated by European Twisted Mass…

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

Results on the electromagnetic form factors of the nucleon using twisted mass fermion configurations are presented. These include a gauge field ensemble simulated with two degenerate light quarks yielding a pion mass of around 130 MeV, as…

We report on a program to compute the electromagnetic form factors of mesons. We discuss the techniques used to compute the pion form factor and present results computed with domain wall valence fermions on MILC asqtad lattices, as well as…

High Energy Physics - Lattice · Physics 2014-11-17 LHP Collaboration , Frederic D. R. Bonnet , Robert G. Edwards , George T. Fleming , Randy Lewis , David G. Richards