Testing χc\chi_c properties at BELLE II

The model of the $\chi_{c_i}-\gamma^*-\gamma^*$ and $\chi_{c_i}-J/\psi^*-\gamma^*$ form factors developed in [1] for $\chi_{c_1}$ and $\chi_{c_2}$ is extended to $\chi_{c_0}$ case. The studies performed within this model have shown that at BELLE II it will be possible to study in detail $\chi_{c_i}-\gamma^*-\gamma$ form factors through measurements of the reaction $e^+e^-\to e^+e^- \chi_{c_i} (\to J/\psi (\to \mu^+\mu^-)\gamma)$.The results were obtained using the newly updated Monte Carlo generator EKHARA

The reaction e+e- --> e+e-pi+pi- and the pion form factor measurements via the radiative return method

The role of the reaction e+e- --> e+ e-pi+pi- in the pion form factor measurements via radiative return method without photon tagging is studied in detail. The analysis is based on the developed Monte Carlo program EKHARA, which ingredients are also presented

The radiative return method - a short theory review

A short review of the status of the theoretical developments concerning the radiative return method is presented. The emphasis is on the construction of the PHOKHARA Monte Carlo event generator and its tests. It is advocated that the radiative return method provides not only with the hadronic cross section extraction competitive with and complementary to the scan method, but also that it is a powerful tool in detailed studies of the hadron interactions.Comment: Talk presented at The International Workshop "e+e- collisions from phi to psi", Novosibirsk, 27 Feb. - 2 March 200

QED Radiative Corrections for [gamma gamma]-production of Hadrons in e+e- Scattering

The theoretical calculation of the leading quantum electrodynamics radiative corrections to the processes of hadron production via the photon–photon interaction in the electron–positron scattering is briefly reviewed

e+ e- ---> pi+ pi- e+ e- : A Potential background for sigma (e+ e- ---> pi+ pi-) measurement via radiative return method

A Monte Carlo generator (EKHARA) has been constructed to simulate the reaction e+e− ! + −e+e− based on initial and final state emission of a e+e− pair from e+e− ! + − production diagram. A detailed study of the process, as a potential background for (e+e− ! + −) measurement via radiative return method, is presented for - and B-factory energies

Present status of precise calculation for small-angle Bhabha scattering

The problem of obtaining a theoretical description of Bhabha scattering at small angle, to monitor the luminosity at the precision 0 .1% requested by LEP experiments, is discussed and recent results are presented

[chi]c1 and [chi]c2 production in e+e- annihilation

Electromagnetic production of c1 and c2 states in e+e annihilation is discussed in the frame of a quarkonium model

FSR corrections to the process e(+)e(-) -> (p)over-barp gamma

Newly developed model of the nucleon form factors is described and the role of the final state emission in the reaction e+e ! pp is discussed

Studies of the Reaction e+e−→ e+e−χci(→ γJ∕ψ(→ μ+μ−)) at Belle II with the Monte Carlo Generator EKHARA

The Belle II experiment with the integrated luminosity of 50 ab 1 will allow for an access to information never available before. In this paper, we concentrate on studies of the chi(ci)-gamma*-gamma* form factors using the Monte Carlo event generator EKHARA. The precise experimental knowledge of the form factors can differentiate between various models giving predictions for the electronic widths Gamma(chi(c1, 2) -> e(+)e(-)), even without direct measurements of these widths