Diachenko M. Resonance effects in the propagation of photons in a magnetic field

Resonant propagation of a polarized photon with consecutive creation and annihilation of electron-positron pair in the presence of a strong magnetic field has been considered. Changing the polarization of a photon in a resonant and non-resonant cases has been investigated and it has been shown that in most cases the photon has an anomalous linear polarization . An exception is the case of the normal linear polarized of initial photon , when the photon propagates without changing the polarization. The resonant two-photon production of electron-positron pairs in the ultraquantum approximation for arbitrarily polarized particles has been investigated. It has been shown that the cross section is the largest in order of magnitude for spin direction of electronpositron pair against the magnetic field for the electron and along the magnetic field for the positron . The passage of charged particles through an electron gas has been considered in the frame of quantum field approach. Taking into account the second Born approximation the dependence of the energy loss of a charged particle in the electron gas on the sign of the charge has been found. It has been shown that the ratio of the second correction to the first Born approximation is proportional to the small task parameter.