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Related papers: Pion Form Factors in Holographic QCD

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We investigate the pion electromagnetic half off-shell form factors, which parametrize the matrix element of the charged pion electromagnetic current with one leg off-mass-shell and the other leg on-mass-shell, using an exactly solvable…

High Energy Physics - Phenomenology · Physics 2020-01-01 Ho-Meoyng Choi , T. Frederico , Chueng-Ryong Ji , J. P. B. C. de Melo

We compute the Kl3 and pion form factors using partially twisted boundary conditions. The twists are chosen so that the Kl3 form factors are calculated directly at zero momentum transfer (q^2=0), removing the need for a q^2 interpolation,…

High Energy Physics - Lattice · Physics 2010-01-21 P. A. Boyle , J. M. Flynn , A. Jüttner , C. Kelly , H. Pedroso de Lima , C. M. Maynard , C. T. Sachrajda , J. M. Zanotti

We present preliminary results from the first calculation of the pion electromagnetic form factor at physical light quark masses. This form factor parameterises the deviations from the behaviour of a point-like particle when a photon hits…

High Energy Physics - Lattice · Physics 2013-11-15 Jonna Koponen , Francis Bursa , Christine Davies , Gordon Donald , Rachel Dowdall

We study pion in the holographic model of Hirn and Sanz which contains two Yang-Mills fields defined in the background of the sliced AdS space. The infrared boundary conditions imposed on these fields generate the spontaneous breaking of…

High Energy Physics - Phenomenology · Physics 2008-12-15 Hovhannes R. Grigoryan , Anatoly V. Radyushkin

The pionic contribution to the g-2 of the muon involves a certain integral over the the modulus squared of F_\pi(t), the pion electromagnetic form factor. We extend techniques that use cut-plane analyticity properties of F_\pi(t) in order…

High Energy Physics - Phenomenology · Physics 2008-11-26 B. Ananthanarayan , S. Ramanan

In the framework of Dyson-Schwinger equations (DSE), we compute the $\gamma^*\gamma\to\pi^0$ transition form factor, $G(Q^2)$. For the first time, in a continuum approach to quantun chromodynamics (QCD), it was possible to compute $G(Q^2)$…

Nuclear Theory · Physics 2016-11-23 Khépani Raya

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

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

The data analysis for the reaction H(e,e' pi^+)n, which was used to determine values for the charged pion form factor Fpi for values of Q^2=0.6-1.6 GeV^2, has been repeated with careful inspection of all steps and special attention to…

We consider the electromagnetic form factors of strange vector, axial vector and pseudoscalar mesons in a holographic QCD model. We find the charge radius of charged kaon agrees with the experiment, while the charge radius of charged pion…

High Energy Physics - Phenomenology · Physics 2010-04-27 H. Z. Sang , Xiao-Hong Wu

The QCD evolution of the pion distribution amplitude (DA) $\phi_\pi(x,Q^2)$ is computed for several commonly used models. Our analysis includes the nonperturbative form predicted by light-front holographic QCD, thus combining the…

High Energy Physics - Phenomenology · Physics 2011-08-12 Stanley J. Brodsky , Fu-Guang Cao , Guy F. de Teramond

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

Employing the standard hard-scattering approach and the running coupling method we calculate a class of power-suppressed corrections $\sim 1/Q^{2n},n=1,2,3,...$ to the electromagnetic $\pi^0\gamma$ transition form factor (FF)…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. S. Agaev

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

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

Following Polchinski and Strassler [1] and our previous work [2], we study high-energy pion scattering in the holographic QCD hard-wall model. In particular, we focus on comparing our predictions for the angular dependence of $\pi^{+}…

High Energy Physics - Phenomenology · Physics 2026-04-08 Adi Armoni , Dorin Weissman

We calculate electromagnetic pion form factors with an analytic model for $\alpha_{\rm s}(Q^2)$ which is infrared (IR) finite without invoking a ``freezing'' hypothesis. We show that for the asymptotic pion distribution amplitude, $F_{\pi…

High Energy Physics - Phenomenology · Physics 2009-10-31 N. G. Stefanis , W. Schroers , H. -Ch. Kim

We use the recently measured accurate BaBaR data on the modulus of the pion electromagnetic form factor, $F_\pi(t)$, up to an energy of 3 GeV, the I=1 $P$-wave phase of the $\pi\pi$ scattering amplitude up to the $\omega-\pi$ threshold, the…

High Energy Physics - Phenomenology · Physics 2012-06-20 I. Sentitemsu Imsong , B. Ananthanarayan , Irinel Caprini

We discuss a novel and simple parametrisation of the pion vector form factor that transparently connects spacelike and timelike regions of the momentum transfer $q^2$. Our parametrisation employs the framework of conformal mapping and…

High Energy Physics - Phenomenology · Physics 2025-02-12 Matthew Kirk , Bastian Kubis , Méril Reboud , Danny van Dyk

The $^{1}$H($e,e^\prime \pi^+$)n cross section was measured for a range of four-momentum transfer up to $Q^2$=3.91 GeV$^2$ at values of the invariant mass, $W$, above the resonance region. The $Q^2$-dependence of the longitudinal component…

Nuclear Experiment · Physics 2009-11-13 T. Horn