Related papers: Periodic interference structures in the time-like …
We have recently highlighted the presence of a periodically oscillating 10 \% modulation in the BABAR data on the proton timelike form factors, in the reaction $e^++e^-$ $\rightarrow$ $\bar{p}+p$. Here we deepen our previous data analysis,…
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…
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 discussion on the asymptotical behaviour of the form factors in the space-like and time-like regions have been corrected and clarified. Fig.3 has been replaced by an improved analysis of the data.
Hadron electromagnetic form factor in the time-like region at the boundary of the physical region is considered. The energy behavior of the form factor is shown to be determined by the strong hadron-antihadron interaction. Imaginary parts…
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,…
The reactions ppbar -> e+e- and e+e- -> ppbar are analyzed in the near-threshold region. Specific emphasis is put on the role played by the interaction in the initial- or final antinucleon-nucleon state which is taken into account…
The process $ \bar{p} p \rightarrow e^{-} e^{+} $ is considered in the general case of polarized initial particles. A relation between the difference of the phases of the electromagnetic form factors $G_M$ and $G_E$ in the time-like region…
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…
In the reaction of the antiproton-deuteron electromagnetic annihilation pbar + d --> e+e-n the value of the invariant mass M of the (e+e-) pair can be near or below the (pbar p) mass even for enough high momentum of incident antiproton.…
We have performed numerical simulations of the unpolarized e+e- --> p pbar process in kinematic conditions under discussion for a possible upgrade of the existing DAFNE facility. By fitting the cross section angular distribution with a…
The difference between the timelike and spacelike meson form factors is analysed in the framework of perturbative QCD with Sudakov effects included. It is found that integrable singularities appear but that the asymptotic behavior is 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…
A new mechanism of baryon-antibaryon production via nonperturbative double pair creation in intermediate mesons is proposed and the theory contains no fitting parameters. It is shown, that near-threshold resonances are responsible for…
We present several recent results from the BaBar collaboration in the areas of initial state radiation physics and transition form factors. An updated study of the processes e+e- -> K+K-pi+pi- and e+e- -> K+K-pi0pi0 provides an improved…
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.
Hadron electromagnetic form factors contain dynamical information on the intrinsic structure of the hadrons. The pioneering work developed at the Kharkov Physical-Technical Institute in the 60's on the relation between the polarized cross…
We have performed numerical simulations of the single-polarized e+ e- --> \vec p anti p process in kinematic conditions under discussion for a possible upgrade of the existing DAFNE facility. By fitting the cross section and spin asymmetry…
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…
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…