Neutrino oscillations in electromagnetic fields

Oscillations of neutrinos νL↔νR in presence of an arbitrary electromagnetic field are considered. We introduce the Hamiltonian for the neutrino spin-evolution equation that accounts for possible effects of interaction of neutrino magnetic μ and electric ϵ dipole moments with the transversal (in respect to the neutrino momentum) and also the longitudinal components of electromagnetic field. Using this Hamiltonian we predict the new types of resonances in the neutrino oscillations νL↔νR in the presence of the field of an electromagnetic wave and in combination of an electromagnetic wave and constant magnetic field. The possible influence of the longitudinal magnetic field on neutrino oscillations is emphasized.