Related papers: $\Delta$ contribution in $e^+ + e^- \to p + \bar{p…
We study the characteristics of the low mass ppbar enhancements near threshold in the three-body decays B+ to p pbar K+ and B+ to p pbar pi+. We observe that the proton polar angle distributions in the ppbar helicity frame in the two decays…
A model independent formalism for the electron positron annihilation reaction $e^++e^-\to a_1(1260)+\pi $ has been derived. The differential and total cross sections and the elements of the spin--density matrix of the $a_1$-meson were…
Born differential cross sections and the lowest-order radiative correction to them are obtained in the kinematics of large-angle final photons emission in high-energy electron-positron annihilation processes. Taking into account possible…
We address the discrepancy between the Rosenbluth and polarization transfer data for the electromagnetic form factors of the nucleon. Assuming that the effect of two-photon corrections on the polarization transfer data is negligible, we…
We calculate the non-singlet, the pure singlet contribution, and their interference term, at $O(\alpha^2)$ due to electron-pair initial state radiation to $e^+ e^-$ annihilation into a neutral vector boson in a direct analytic computation…
The two-pion contribution to hadronic vacuum polarization can be extracted from tau decay data when isospin violating and radiative corrections are taken into account. When the dominant corrections are applied to the photon-inclusive decay…
The general analysis of the differential cross section and various polarization observables is performed for the process $e^+ + e^- \to N + \bar N +\pi^0 $ assuming that the annihilation occurs through the exchange of one virtual photon.…
A model for the reaction $\gamma p\to\rho^-\Delta^{++}$ is presented with the $t$-channel $\pi+\rho$ exchanges reggeized to describe the reaction up to high energies. Gauge invariance of $\rho$ exchange is discussed in connection with the…
Forward-backward (charge) asymmetry in the processes of $e^+e^-$ annihilation into a pair of charged pseudoscalar mesons is recalculated in the one-loop approximation. The exact dependence on the meson masses is taken into account. Results…
In this work, the two-photon-exchange (TPE) effect in $ep\rightarrow en\pi^+$ at small $-t$ is discussed. In the previous work, the TPE contribution with one $\pi$ intermediate state is estimated numerically within a hadronic model under…
After recalling the arguments for possible excess of two-photon contribution over $\alpha$-counting, model independent statements about the consequences on the observables will be given. The relevant experimental data are discussed:…
We study the production of two almost back-to-back hadrons from the annihilation of an electron and a positron, allowing for the polarization of all particles involved. In particular, we conduct a general (model-independent) structure…
In this work we generalize the entropy transfer from electron-positron annihilation to photons in the early Universe. The generalization is implemented within the Tsallis formalism by using generalized distribution functions derived from…
Precise helicity-dependent cross sections and the double-polarization observable $E$ were measured for $\eta$ photoproduction from quasi-free protons and neutrons bound in the deuteron. The $\eta\rightarrow 2\gamma$ and $\eta\rightarrow…
Events with tagged photons in the process of electron-positron annihilation into hadrons are considered. The initial state radiation is suggested to scan the hadronic cross section with the energy. QED radiative corrections are taken into…
We calculate the exclusive cross sections for e^+ e^- annihilation into two charmonium states through a virtual photon. Purely electromagnetic contributions are surprisingly large, changing the cross sections by as much as 21%. The…
In frames of agreement to consider the annihilation of electron-positron pair to hadrons cross section to be including the virtual photon polarization effects a new formulation of hadron contribution to muon anomalous magnetic moment is…
In this work, the two-photon-exchange (TPE) effects in the unpolarized $\mu p$ scattering are discussed within the hadronic model where the intermediate states $N,\Delta$ and $\sigma$ are considered. The contribution from the $N$…
We report the first observation of the spontaneous polarization of $\Lambda$ and $\bar{\Lambda}$ hyperons transverse to the production plane in $e^+e^-$ annihilation, which is attributed to the effect arising from a polarizing fragmentation…
A detailed study of two-photon exchange in unpolarized and polarized elastic electron--nucleon scattering is presented, taking particular account of nucleon finite size effects. Contributions from nucleon elastic intermediate states are…