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Related papers: QCD sum rules: form factors and wave functions

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We present an analysis of QCD sum rules for pion form factor in next-to-leading order of perturbation theory for the case of axial-vector pion currents. The theoretical predictions for Q^2-dependence of pion form factor are in good…

High Energy Physics - Phenomenology · Physics 2009-11-10 V. V. Braguta , A. I. Onishchenko

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 extend recently developed methods used for determining the electromagnetic charge radius and $a_\mu^{\pi\pi}$ to obtain a determination of the electromagnetic form factor of the pion, $F_\pi^V(t)$, in several significant kinematical…

High Energy Physics - Phenomenology · Physics 2019-01-02 B. Ananthanarayan , Irinel Caprini , Diganta Das

We discuss the status of the pion distribution amplitude (DA) from analyzing the CLEO experimental data in the context of QCD sum-rule techniques and QCD perturbation theory at the NLO accuracy. The constraints extracted this way for the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Alexander P. Bakulev , S. V. Mikhailov , N. G. Stefanis

We investigate a model QCD sum rule for the pion wave function $\varphi_{\pi}(x)$ based on the non-diagonal correlator whose perturbative spectral density vanishes and $\Phi(x,M^2)$, the theoretical side of the sum rule, consists of…

High Energy Physics - Phenomenology · Physics 2007-05-23 Anatoly Radyushkin

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

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 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

We study the $P\to\gamma\,\gamma^*$ ($P=\pi^0,\eta,\eta'$) transition form factors by means of the local-duality (LD) version of QCD sum rules. For the case of $\eta$ and $\eta'$, the conventional LD model provides a good description of the…

High Energy Physics - Phenomenology · Physics 2012-02-23 Wolfgang Lucha , Dmitri Melikhov

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 discuss different QCD approaches to calculate the form factor F^{\gamma^*\gamma\pi}(Q^2) of the \gamma^*\gamma\to\pi^{0} transition giving preference to the light-cone QCD sum rules (LCSR) approach as being the most adequate. In this…

High Energy Physics - Phenomenology · Physics 2009-11-07 A. P. Bakulev , S. V. Mikhailov , N. G. Stefanis

Electromagnetic form factors of the transition $\pi+\gamma_{virt.}\ra A_1$ are calculated by QCD sum rules technique with the description of the pion in terms of the set of wave functions of increasing twist. Obtained results are compared…

High Energy Physics - Phenomenology · Physics 2014-11-17 V. M. Belyaev

We present a quantitative analysis of the electromagnetic pion form factor in the light-cone sum rule approach, including radiative corrections and higher-twist effects. The comparison to the existing data favors the asymptotic profile of…

High Energy Physics - Phenomenology · Physics 2011-05-05 V. M. Braun , A. Khodjamirian , M. Maul

We use dispersive techniques to address the behavior of the pion form factor as $Q^2 \to \infty$ and $Q^2 \to 0$. We perform the matching with the constraints of perturbative QCD and chiral perturbation theory in the high energy and low…

High Energy Physics - Phenomenology · Physics 2011-07-19 John F. Donoghue , Euy Soo Na

The local-duality formulation of QCD sum rules allows for the prediction of hadronic form factors without knowledge of the subtle details of their structure. With the aid of this formalism, we take a fresh look at the behaviours of the…

High Energy Physics - Phenomenology · Physics 2012-05-31 Irina Balakireva , Wolfgang Lucha , Dmitri Melikhov

We provide a theoretical update of the calculations of the pi0-gamma*-gamma form factor in the LCSR framework, including up to six polynomials in the conformal expansion of the pion distribution amplitude and taking into account twist-six…

High Energy Physics - Phenomenology · Physics 2011-03-22 S. S. Agaev , V. M. Braun , N. Offen , F. A. Porkert

We give a short review of QCD sum rule results for B and D mesons and Lambda_Q and Sigma_Q baryons. We focus mainly on recent developments concerning semileptonic B->pion and D->pion transitions, pion couplings to heavy hadrons, decay…

High Energy Physics - Phenomenology · Physics 2007-05-23 O. Yakovlev , R. Rückl , S. Weinzierl

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 present an analysis of QCD sum rules for pion form factor in next-to-leading order of perturbation theory for the case of pseudoscalar pion currents. The essential instanton contribution is reanalysed with account for present more…

High Energy Physics - Phenomenology · Physics 2009-11-10 V. V. Braguta , A. I. Onishchenko

The introduction of partially twisted boundary conditions allows weak and electromagnetic form factors to be evaluated at specified values of the hadronic momenta (and hence momentum transfers) in lattice simulations. We present and…

High Energy Physics - Lattice · Physics 2009-11-13 P. A. Boyle , J. M. Flynn , A. Juttner , C. T. Sachrajda , J. M. Zanotti