Related papers: Asymptotic behavior of pion form factors
We consider the electromagnetic and transition pion form factors. Using dispersion relations we simultaneously describe both the hadronic, time-like region and the asymptotic region of large energy-momentum transfer. For the latter we…
The structure of hadronic form factors at high energies and their deviations from perturbative quantum chromodynamics provide insight on nonperturbative dynamics. Using an approach that is consistent with dispersion relations, we construct…
We compare the existing data about electromagnetic form factors of the proton in the time-like region of momentum transfer (up to $q^2\simeq$ 14 (GeV/c)$^2$), with the corresponding data in the space-like region. From the constrains given…
Form factors of nucleons and mesons with timelike momentum transfers are discussed. New experimental results for protons, pions, and kaons at large momentum transfers are presented, and the inadequacy of existing theoretical ideas about…
We present our calculations of the electromagnetic form factor of pions. We explore the properties of pion form factor at momentum transfer larger than previous studies by including more combinations of source and sink momenta and using…
We present a construction of the pion electromagnetic form factor where the transition from large-Nc Regge vector meson dominance models with infinitely many resonances to perturbative QCD is built in explicitly. The construction is based…
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…
We extend a recent analysis of the pion electromagnetic form factor constrained by the conformal symmetry to explore the time-like region. We show explicitly that the time-like form factor obtained by the analytic continuation of the…
The pion electromagnetic form factor and two-pion production in electron-positron collisions are simultaneously fitted by a vector dominance model evolving to perturbative QCD at large momentum transfer. This model was previously successful…
The asymptotics of pion charge form factor is obtained in the framework of relativistic Hamiltonian dynamics for the infinite value limit of momentum transfer and zero value limit of constituent--quark mass. It is shown that this…
We analyze the pion transition form factor using dispersion theory. We calculate the singly-virtual form factor in the time-like region based on data for the $e^+e^-\to 3\pi$ cross section, generalizing previous studies on…
The electromagnetic form factors of hadrons at large momentum transfer have been the subject of intense theoretical and experimental scrutiny over the past two decades, yet there is still not a universally-accepted framework for their…
Recent improvements of the hard scattering picture for the large $p_{\perp}$ behaviour of electromagnetic form factors, namely the inclusion of both Sudakov corrections and intrinsic transverse momentum dependence of the hadronic wave…
New, accurate measurements of the pion and kaon electromagnetic form factors are expected in the near future from experiments at electron-positron colliders,using the radiative return method. We construct a model for the timelike pion…
We consider the electromagnetic transition form factors of the Roper resonance in the framework of an effective field theory of pions, nucleons and delta and Roper resonances as explicit degrees of freedom. Due to the lack experimental data…
An approach for describing the electromagnetic form factors of hadrons, in the space- and time-like regions, within a constituent quark model on the light front is shortly illustrated and calculations for the pion case are reported. Three…
The behaviour of the pion transition form factor for the process $\gamma^\star\gamma \to \pi^0$ and $\gamma^\star\gamma^\star\to \pi^0$ at space-like values of photon momenta is estimated within the nonlocal covariant quark-meson model. The…
The pion electromagnetic form factor is investigated by using the dispersion relation with the superconvergence condition, which was proposed to synthesize the vector meson dominance model and QCD. The absorptive part is given as an…
We employ a dispersion relation that allows to recover the phase of the electromagnetic form factor of the pion from its absolute value above threshold. Compared to alternative approaches building on the phase, this approach builds on…
We extend our relativistic theory of gravitational structure of composite hadrons to obtain the pion gravitational form factors at large momentum transfers. The approach was used in the case of intermediate region of the variable in our…