Narrow Results

Qualitative analysis of additional energy of neutrino and antineutrino in plasma is performed. A general expression for the neutrino self-energy operator is obtained in the case of ultra-high energies when the local limit of the weak interaction is not valid. The neutrino and antineutrino additional energy in plasma is calculated using the dependence of the W- and Z-boson propagators on the momentum transferred. The kinematical region for the neutrino radiative transition (the so-called "neutrino spin light") is established for some important astrophysical cases. For high energy neutrino and antineutrino, dominating transition channels in plasma, ν_e + e⁺ → W⁺, and , are indicated.

The vertex function at the limit of small momentum transferred of a virtual massive neutrino in ξ-gauge is calculated via neutrino self-energy operator in a constant electromagnetic field. The expressions for neutrino magnetic moment under various relations between masses of neutrino, W-boson and charged lepton are presented.

Various forms of expressions for the propagators of charged particles in a constant magnetic field that should be used for investigations of electroweak processes in an external uniform magnetic fields are discussed. Formulas for the propagators of the Standard Model charged $W$- and scalar $\Phi$-bosons in an arbitrary $\xi$-gauge, expanded over Landau levels, are derived for the first time.