Neutrino oscillations in electromagnetic fields

Oscillations of neutrinos nu (L) <---->,nu (R) 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 inte raction of neutrino magnetic mu and electric is an element of dipole moment s with the transversal tin respect to the neutrino momentum) and also the l ongitudinal components of electromagnetic field. Using this Hamiltonian we predict the new types of resonances in the neutrino oscillations nu (L) <-- --> nu (R) in the presence of the field of an electromagnetic wave and in c ombination of tan electromagnetic wave and constant magnetic field. The pos sible influence of the longitudinal magnetic field on neutrino oscillations is emphasized. (C) 2000 Elsevier Science B.V. All rights reserved.