Related papers: Compared analysis of time-like hyperon form factor…
New possibilities of high precision measurements of hadron form factors in annihilation and scattering reactions over an unexplored kinematical region suggest a compared analysis, in view of a global description of the nucleon structure.
Based on the experimental measurements of the electron-positron annihilation reactions into a baryon ($B$) and anti-baryon ($\bar{B}$) pair, the electromagnetic form factors of hyperons in the time-like region can be investigated within the…
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…
The latest BABAR results on the proton and kaon timelike form factors (FF) are presented. The special emphasize is made on comparison of the spacelike and timelike FFs and the rise of the proton FF near threshold. The behavior of the cross…
An overview of recent data on electromagnetic hadron form factors is presented and discussed in terms of selected nucleon models in space-like and time-like regions. Model independent properties connecting scattering and annihilation…
Data on electromagnetic form factors of proton, neutron, and $\Lambda$ from annihilation and scattering reactions are collected and interpreted in the frame of a generalized picture of the internal structure of baryons which holds in…
There has been considerable progress in the study of the electromagnetic form factors of baryons in the timelike region, through electron-positron scattering reactions ($e^+ e^- \to B \bar B$), in the last two decades. Timelike experiments…
The data on the proton form factors in the time-like region from the BaBar, BESIII and CMD-3 Collaborations are examined to have coherent pieces of information on the proton structure. Oscillations in the annihilation cross section,…
In the last few years there has been considerable progress in the study of the electromagnetic form factors of baryons in the timelike region, through electron-positron scattering, with increasing squared transfer momentum $q^2$. The…
We use the available information on the ratio between the electric and magnetic proton form factors coming from recently published space-like data and from the few available time-like data. We apply a dispersive procedure on these data to…
We perform a global analysis of the experimental data of the electromagnetic nucleon form factors, in space-like and time-like regions. We give the expressions of the observables in annihilation processes, such as $p+\bar{p}\to \ell^+…
The proton form factor, two-photon annihilations into $p\bar{p}$ as well as exclusive charmonium decays are critically examined. It will be argued that the standard perturbative QCD analysis of these reactions fails, i.e. the need for…
Form factors of the proton, pion, and kaon for large timelike momentum transfers have recently been measured with precision. The results and future prospects are discussed.
A review of recent precision measurements of the electromagnetic form factors of the mesons, pion and kaon, and the hyperons, $\Lambda^0$, $\Sigma^0$, $\Sigma^+$, $\Xi^-$, $\Xi^0$, $\Omega^-$, at large timelike momentum transfers is…
We discuss in rather general terms the properties of space-like baryon transition form factors. In particular, we argue why these are necessarily complex-valued, what can be deduced from the respective phase motion and why dealing with real…
The electromagnetic form factors of the proton in the time-like region and two-photon annihilations into proton-antiproton are investigated. To calculate these processes at moderately large $s$ we use a variant of the Brodsky-Lepage…
We present estimates of the hyperon elastic form factors for the baryon octet and the $\Omega^-$ baryon for large four-momentum transfer squared, $q^2$, in the timelike region ($q^2>0$). Experimentally, those form factors can be extracted…
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…
Meson decays are considered within the constituent quark model, making use of the dispersion formulation of the model: Starting with spacelike momentum transfers $q$, meson transition form factors are expressed as relativistic invariant…
It is the first time that the study of three-body baryonic B decays offers an independent determination of the nucleon form factors for the time-like four momentum transfer $(t>0)$ region, such as $G^{p,n}_M(t)$ of vector currents and those…