Quantization of massive fermions in vacuum and external fields

We study massive Majorana neutrinos in background matter. Representing these particles in terms of Weyl spinors, we carry out their quantization. The propagators of these fields are also constructed. Then, we apply the Hamilton dynamics based formalism to describe massive Majorana neutrinos in matter on the classical level. Finally, we study a classical Dirac particle in vacuum, described with $c$-number variables, within the Hamiton formalism. Such a Dirac field is also canonically quantized.