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Related papers: Pion form factor in the QCD sum-rule approach with…

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We apply the perturbative chiral quark model at one loop to analyze the electromagnetic form factors of the baryon octet. The analytic expressions for baryon form factors, which are given in terms of fundamental parameters of low-energy…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Cheedket , V. E. Lyubovitskij , Th. Gutsche , Amand Faessler , K. Pumsa-ard , Y. Yan

We perform a nonperturbative lattice calculation of the complex phase and modulus of the pion form factor in the timelike momentum region using the finite-volume technique. We use two ensembles of 2+1-flavor overlap fermion at pion masses…

High Energy Physics - Lattice · Physics 2015-03-18 Xu Feng , Sinya Aoki , Shoji Hashimoto , Takashi Kaneko

Using QCD sum rules with nonlocal condensates the twist-2 pion distribution amplitude is determined by means of its moments and their confidence intervals, including also radiative corrections. An admissible set of pion distribution…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. P. Bakulev , S. V. Mikhailov , N. G. Stefanis

We combine the constraints on the pion quark structure available from perturbative QCD, nonperturbative QCD (nonlocal QCD sum rules and light cone sum rules) with the analysis of current data on F_{\pi\gamma\gamma^*}(Q^2), including recent…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. P. Bakulev , S. V. Mikhailov , N. G. Stefanis

We analyze the accuracy of the pion elastic form factor predicted by a local-duality (LD) version of dispersive sum rules. To probe the precision of this theoretical approach, we adopt potential models with interactions that involve both…

High Energy Physics - Phenomenology · Physics 2015-03-19 Irina Balakireva , Wolfgang Lucha , Dmitri Melikhov

We calculate the scalar form factor of the pion using two dynamical flavors of non-perturbatively $\mathcal{O}(a)$-improved Wilson fermions, including both the connected and the disconnected contribution to the relevant correlation…

High Energy Physics - Lattice · Physics 2014-05-14 Vera Gülpers , Georg von Hippel , Hartmut Wittig

We consider a bottom-up AdS/QCD model with a conformal exponential deformation $e^{k\,z^2}$ on a Lorentz invariant AdS background. In this model, we assume the conformal dimension associated with the operator that creates pions at the…

High Energy Physics - Phenomenology · Physics 2022-03-29 Miguel Angel Martin Contreras , Eduardo Folco Capossoli , Danning Li , Alfredo Vega , Henrique Boschi-Filho

We analyse the perturbative contributions from the higher helicity ($\lambda_{1}+\lambda_{1}=\pm 1$) components, which should be naturally contained in the light-cone wave function for the pion as a consequence of the Wigner rotation, in…

High Energy Physics - Phenomenology · Physics 2009-10-28 Bo-Qiang Ma , Tao Huang

We study the constraints arising on the expansion parameters c and d of the Pion electromagnetic form factor from the inclusion of pure space-like data and the phase of time-like data along with one space-like datum, using as input the…

High Energy Physics - Phenomenology · Physics 2009-07-22 Gauhar Abbas , B. Ananthanarayan , S. Ramanan

This talk presents issues pertaining to the quark structure of the pion within QCD, both from the theoretical and from the experimental point of view. We review and discuss the pion-photon transition form factor and the pion's…

High Energy Physics - Phenomenology · Physics 2008-11-07 N. G. Stefanis

The pion form factor at very large $Q^2$ is obtained by using a new pion wave function. It shows that when $Q^2>>(1.8GeV)^2$ the pion form factor reaches the asymptotic limit ${\alpha_s(Q^2)\over Q^2}$

High Energy Physics - Phenomenology · Physics 2007-05-23 Bing An Li

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 apply the method of QCD sum rules in the presence of external electromagnetic fields $F_{\mu\nu}$ to the problem of the electromagnetic decays of various vector mesons, such as $\rho\to\pi\gamma$, $K^\ast\to K\gamma$ and…

Nuclear Theory · Physics 2009-10-31 Shi-lin Zhu , W. -Y. P. Hwang , Ze-sen Yang

We formulate the nonlocal NJL model with a momentum dependent constituent quark mass and calculate pion light cone wave functions of twist 2 and 3. The leading twist wave function is not asymptotic and agrees well with the new CLEO data.…

High Energy Physics - Phenomenology · Physics 2007-05-23 Michal Praszalowicz , Andrzej Rostworowski

The electromagnetic and gravitational form factors of the nucleon are studied simultaneously using a covariant quark-diquark approach, and the pion cloud effect on the form factors is explicitly discussed. In this study, the electromagnetic…

High Energy Physics - Phenomenology · Physics 2025-08-14 Jiaqi Wang , Dongyan Fu , Yubing Dong

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 propose a new approach to construct QCD sum rules for the pi NN coupling constant, g, starting from the vacuum-to-pion correlation function of the interpolating fields of two nucleons and taking its matrix element with respect to nucleon…

Nuclear Theory · Physics 2009-11-07 Yoshihiko Kondo , Osamu Morimatsu

A continuum approach to quark-antiquark bound-states is used to determine the electromagnetic form factors of pion-like mesons with masses $m_{0^-}/{\rm GeV}=0.14$, $0.47$, $0.69$, $0.83$ on a spacelike domain that extends to $Q^2 \lesssim…

Nuclear Theory · Physics 2018-12-05 Muyang Chen , Minghui Ding , Lei Chang , Craig D. Roberts

We use chiral perturbation theory to study the extraction of pion electromagnetic polarizabilities from lattice QCD. Chiral extrapolation formulae are derived for partially quenched QCD, and quenched QCD simulations. On a torus, volume…

High Energy Physics - Lattice · Physics 2008-11-26 Jie Hu , Fu-Jiun Jiang , Brian C. Tiburzi

Content : 1) The leading twist pion wave function, 2) "Improved" QCD sum rules with non-local condensates, 3) Pion and kaon form factors and charmonium decays: theory vs experiment, 4) \gamma^{*}\gamma\pi^{o} - form factor, 5) The new…

High Energy Physics - Phenomenology · Physics 2009-11-11 Victor L. Chernyak
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