In this presentation the results of theoretical calculations for the electron-positron annihilation into hadrons and photons will be presented. The wide range of the subjects will be covered with the emphasis on the calculations of the radiative corrections and its implementation in the PHOKHARA Monte Carlo event generator. The subjects important from the point of view of the discrepancy between experimental value and the Standard Model predictions of the the anomalous magnetic moment of the muon will be discussed. One of them is modeling of the two-photon pseudoscalar mesons transition form factors, which have an impact for determination of the hadronic light-by-light contribution. The second, calculations of the next-to-leading-order radiative corrections for the pion pair production cross section, which are important input for the data analysis of the BABAR and KLOE measurements, where one observes the discrepancy. The another subject is connected with the proton radius puzzle. The modeling of the nucleon form factors is the first step in calculation of the complete radiative corrections to the electron-proton scattering as the two-photon contributions to this reaction involve knowledge of the proton transition form factors. The impact of the final state radiative corrections for the extraction of the p ̄p cross section via radiative return will be discussed. This cross section could give an information about proton form factors in the time-like region.
The last subject covers the production of the states with even charge conjugation and parity. The model for electronic widths of the χc1and χc2 will be presented. A reaction will be proposed, where the resonant signal of these states could be observed through the interference with the radiative return background.