Lagrangian quantum field theory in momentum picture. II. Free spinor   fields
  Free spinor fields, with spin 1/2, are explored in details in the momentum picture of motion in Lagrangian quantum field theory. The field equations are equivalently written in terms of creation and annihilation operators and on their base the anticommutation relations are derived. Some problems concerning the vacuum and state vectors of free spinor field are discussed. Several Lagrangians, describing free spinor fields, are considered and the basic consequences of them are investigated. 
Bozhidar Z. Iliev (Institute for Nuclear Research and Nuclear Energy,   Bulgarian Academy of Sciences, Sofia, Bulgaria)