Neutrino Self-Energy and Index of Refraction in Strong Magnetic Field: A New Approach

The Ritus' $E_{p}$ eigenfunction method is extended to the case of spin-1 charged particles in a constant electromagnetic field and used to calculate the one-loop neutrino self-energy in the presence of a strong magnetic field.From the obtained self-energy, the neutrino dispersion relation and index of refraction in the magnetized vacuum are determined within the field range $m_{e}^{2}\ll eB\ll M_{W}^{2}$. The propagation of neutrinos in the magnetized vacuum is anisotropic due to the dependence of the index of refraction on the angle between the directions of the neutrino momentum and the external field. Possible cosmological implications of the results are discussed.