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We discuss the status of the pion distribution amplitude (DA) in connection with QCD sum rules and experimental data on the $\gamma^*\gamma^\to \pi^0$ transition form factor. Contents: (a) Pion DA in generalized QCD Sum Rules (SRs); (b)…

High Energy Physics - Phenomenology · Physics 2010-12-17 Alexander P. Bakulev , S. V. Mikhailov , N. G. Stefanis

We discuss the QCD sum-rule approach for the spacelike electromagnetic pion form factor in the $O(\alpha_s)$ approximation. We show that the nonlocality of the condensates is a key point to include nonperturbative contributions to the pion…

High Energy Physics - Phenomenology · Physics 2010-02-18 Alexander P. Bakulev , A. V. Pimikov , N. G. Stefanis

We generalize a recent model-independent form factor parameterization derived from rigorous dispersion relations to include constraints from data in the timelike region. These constraints dictate the convergence properties of the…

High Energy Physics - Phenomenology · Physics 2014-11-17 W. W. Buck , Richard F. Lebed

The electromagnetic form factor of the pion in the space-like region, and at finite temperature, $F_{\pi}(Q^{2},T)$, is obtained from a QCD Finite Energy Sum Rule. The form factor decreases with increasing T, and vanishes at some critical…

High Energy Physics - Phenomenology · Physics 2009-10-28 C. A. Dominguez , M. Loewe , J. S. Rozowsky

The pion form factor plays a crucial role in the determination of the contribution of the hadronic vacuum polarisation to the muon anomalous magnetic moment. In order to measure this quantity, energy-scan experiments rely on Monte Carlo…

High Energy Physics - Phenomenology · Physics 2025-12-23 Francesco P. Ucci

We investigate the scalar K pi form factor at low energies by the method of unitarity bounds adapted so as to include information on the phase and modulus along the elastic region of the unitarity cut. Using at input the values of the form…

High Energy Physics - Phenomenology · Physics 2014-11-20 Gauhar Abbas , B. Ananthanarayan , I. Caprini , I. Sentitemsu Imsong , S. Ramanan

We study the pion form factor in a broad range of spacelike momentum transfers within the local-duality version of QCD sum rules. We make use of the recently calculated two-loop double spectral density of the $<AVA>$ correlator including…

High Energy Physics - Phenomenology · Physics 2008-11-26 Victor Braguta , Wolfgang Lucha , Dmitri Melikhov

The electromagnetic form factor of the pion is calculated in the "point-form" of relativistic quantum mechanics using simple, phenomenological wave functions. It is found that the squared charge radius of the pion is predicted one order of…

High Energy Physics - Phenomenology · Physics 2015-06-25 A. Amghar , B. Desplanques , L. Theussl

We present our recent results for the pion elastic form factor [1] obtained within a local-duality three-point sum rule (a Borel sum rule in the limit of an infinite Borel parameter). Our analysis includes the O(1) and O(\alpha_s)…

High Energy Physics - Phenomenology · Physics 2009-06-25 Wolfgang Lucha , Dmitri Melikhov

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

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

We present a calculation of the electromagnetic form factor of the pion in $N_f=2+1$ flavor lattice QCD. Calculations are made on the PACS-CS gauge field configurations generated using Iwasaki gauge action and Wilson-clover quark action on…

High Energy Physics - Lattice · Physics 2011-05-09 Oanh Hoang Nguyen , Ken-Ichi Ishikawa , Akira Ukawa , Naoya Ukita

We use rigorous QCD dispersion relations to derive model-independent bounds on the B -> pi l nu, D -> pi l nu and D -> K l nu form factors. These bounds are particularly restrictive when the value of the observable form factor at one or…

High Energy Physics - Phenomenology · Physics 2010-11-01 C. Glenn Boyd , Benjamin Grinstein , Richard F. Lebed

We use recent data on K^+ -> pi^+e^+e^-, together with known values for the pion form factor, to derive the kaon electromagnetic form factor for 0 <q^2 <0.125 (GeV/c)^2. The results are then compared with predictions of the Linear sigma…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Lowe , M. D. Scadron

We suggest to probe the pion light-cone distribution amplitude, applying a dispersion relation for the pion electromagnetic form factor. Instead of the standard dispersion relation, we use the equation between the spacelike form factor…

High Energy Physics - Phenomenology · Physics 2020-11-04 Shan Cheng , Alexander Khodjamirian , Aleksey V. Rusov

An exploratory study of the time-like pion electromagnetic form factor in a Poincar\'e-covariant bound state formalism in the isospin symmetric limit is presented. Starting from a quark interaction kernel representing gluon-intermediated…

High Energy Physics - Phenomenology · Physics 2021-06-16 Ángel S. Miramontes López , Hèlios Sanchis-Alepuz , Reinhard Alkofer

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 originated 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 2007-05-23 A. P. Bakulev

We show that we are able to extract the pion electromagnetic form factor by using the recent charged pion electroproduction data from JLab and a simple t-channel diagram. For this purpose we have performed the Q2-independent and dependent…

High Energy Physics - Phenomenology · Physics 2009-01-22 T. Mart

Using the results on the electromagnetic pion Form Factor (FF) obtained in the $O(\alpha_s)$ QCD sum rules with non-local condensates \cite{BPS09} we determine the effective continuum threshold for the local duality approach. Then we apply…

High Energy Physics - Phenomenology · Physics 2010-04-22 Alexander P. Bakulev