Related papers: Pion form factor from a contact interaction
We present our results on the electromagnetic form factor of pion over a wide range of $Q^2$ using lattice QCD simulations with Wilson-clover valence quarks and HISQ sea quarks. We study the form factor at the physical point with a lattice…
We extract constraints on the pion distribution amplitude from available data on the pion-photon transition form factor in the framework of light-cone sum rules. A pronounced discrepancy $(2.7-3)\sigma$ between the Gegenbauer expansion…
A global fit to the data from different collaborations (CELLO, CLEO, BaBar) on the pion-photon transition form factor is carried out using light-cone sum rules. The analysis includes the next-to-leading QCD radiative corrections and the…
Confronted with some surprising claims about experimentally measured or theoretically expected dependencies on the involved momentum transfer of various form factors of pseudoscalar mesons, we reassess the present status of these quantities…
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 illustrate the progress of covariant QCD phenomenology for the description of meson coupling constants and form factors. As examples, we discuss the $\rho\pi\pi$ and $\gamma \pi\rho$ interactions, the $\rho$ contribution to the pion…
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…
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…
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 ${\alpha_s(Q^2)\over Q^2}$
We study the pion form factor F^{\pi \gamma\gamma^*}(Q^2) in the light-cone sum rule approach, accounting for radiative corrections and higher twist effects. Comparing the results to the CLEO experimental data on F^{\pi…
We calculate the electromagnetic pion form factor at intermediate space-like momentum transfer from the QCD sum rule for the correlation function of two {\it pseudoscalar } interpolating fields and the electromagnetic current. This…
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…
A state-of-the-art analysis of the pion-photon transition form factor is presented based on an improved theoretical calculation that includes the effect of a finite virtuality of the quasi-real photon in the method of light-cone sum rules.…
We study the form factors of the low energy anomalous pion-2-photon and photon-3-pion processes in the nonlocal chiral quark model which incorporates the momentum dependence of the dynamical quark mass and realizes correctly the chiral…
We obtain the distribution amplitude (DA) of the pion from its light-front wave functions in the basis light-front quantization framework. This light-front wave function of the pion is given by the lowest eigenvector of a light-front…
We investigate the form factors for pseudoscalar-meson-photon transitions by means of dispersive QCD sum rules and demonstrate that most of the measurements done so far (in particular, those by BaBar for $\eta,$ $\eta',$ and $\eta_c$ and…
The pion charge and scalar form factors, $F_1(Q^2)$ and $F_0(Q^2)$, are first calculated in different forms of relativistic quantum mechanics. This is done using the solution of a mass operator that contains both confinement and…
A shape of invariant differential cross section for charged hadron production as function of transverse momentum measured in various collider experiments is analyzed. Contrary to the behavior of produced charged kaons, protons and…
We improve the description of pion-photon interactions in the radiative return process $e^+e^-\to \pi^+\pi^-\gamma$ at the next-to-leading order by including the pion form factor in the Feynman rules. We present a general calculation of the…
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…