Related papers: Compared analysis of time-like hyperon form factor…
We update a recent dispersion--theoretical fit to the nucleon electromagnetic form factors by including the existing data in the time--like region. We show that while the time--like data for the proton can be described consistently with the…
Hadron electromagnetic form factors of hadrons in the time-like region at the boundary of the physical region is considered. The energy behaviour of the form factor is shown to be dominantely determined by the strong hadron-antihadron…
The annihilation of a lepton pair into a proton-antiproton pair, and the reverse process, allow for a measurement of the timelike proton form factors. This work aims at studying the corrections due to direct soft interactions between the…
A unified description of spacelike and timelike hadron form factors within a light-front model was successfully applied to the pion. The model is extended to the nucleon to study the role of $q \bar q$ pair production and of nonvalence…
We review the status of baryon form factors with a special focus on the nucleon electromagnetic form factors which are known best. First, we give an introduction into the dispersive analyses and emphasize the role of unitarity and…
Analyticity of nucleon form factors allows to derive sum rules which, using space-like and time-like data as input, can give unique information about behaviors in energy regions not experimentally accessible. Taking advantage from new…
Calculations of form factors in different forms of relativistic kinematics are presented. They involve the instant, front and point forms. In the two first cases, different kinematical conditions are considered while in the latter case,…
Tensor form factors encode essential information about the internal spin structure and tensor dynamics of baryons. In this work, we investigate the tensor form factors of the baryon hyperons $\Omega^-$, $\Sigma^{*+}$, and $\Xi^{*-}$ within…
Baryon form factors can be analyzed in a largely model-independent fashion in terms of two complementary approaches. These are chiral perturbation theory and dispersion relations. I review the status of dispersive calculations of the…
Recent experimental data on space-like and time-like form factors of the nucleon are analyzed in terms of a two-component model with a quark-like intrinsic three-quark structure and quark-antiquark pairs.
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…
The electromagnetic form factors of the $\Lambda$ hyperon in the time-like region are determined precisely through a dispersion-theoretical analysis of the world data for the cross section of the annihilation process $e^+e^-\to…
The electromagnetic form factors of hadrons as measured both in the space like and time like domains provide fundamental information on the nucleon structure and internal dynamics. General expressions, including the lepton mass, for the…
I briefly summarize the application of the Dyson-Schwinger/Faddeev approach to baryon form factors. Recent results for nucleon electromagnetic and axial form factors as well as N-Delta-Gamma electromagnetic transition form factors are…
Predictions for the electromagnetic form factors of the Lambda$, Sigma and Xi hyperons are presented. The numerical calculations are performed within the framework of the fully relativistic constituent-quark model developed by the Bonn…
A symmetry-preserving continuum approach to the calculation of baryon properties in relativistic quantum field theory is used to predict all form factors associated with nucleon-to-$\Delta$ axial and pseudoscalar transition currents,…
Recent experimental data on space- and time-like form factors of the nucleon are analyzed in terms of a two-component model with a quark-like intrinsics structure and a meson cloud. A good overall agreement is found for all electromagnetic…
We present the experimental status of electromagnetic hadron form factors. New and surprising results, based on polarization measurements, have been recently obtained for the electric proton and neutron form factors. In particular, the…
We perform an analysis on the electromagnetic form factors of the $\Lambda$ hyperon in the time-like reaction $e^+e^-\rightarrow \Lambda\bar\Lambda$ by using a modified vector meson dominance model. We consider both the intrinsic structure…
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…