The Feynman-Dyson Propagators for Neutral Particles (Locality or   Non-locality?)
  An analog of the S=1/2 Feynman-Dyson propagator is presented in the framework of the S=1 Weinberg theory. The basis for this construction is the concept of the Weinberg field as a system of four field functions differing by parity and by dual transformations. Next, we analyze the recent controversy in the definitions of the Feynman-Dyson propagator for the field operator containing the S=1/2 self/anti-self charge conjugate states in the papers by D. Ahluwalia et al. and by W. Rodrigues Jr. et al. The solution of this mathematical controversy is obvious. It is related to the necessary doubling of the Fock Space (as in the Barut and Ziino works), thus extending the corresponding Clifford Algebra. However, the logical interrelations of different mathematical foundations with the physical interpretations are not so obvious. Physics should choose only one correct formalism, it is not clear, why two correct mathematical formalisms (which are based on the same postulates) lead to different physical results? 
Valeriy V. Dvoeglazov
physics.gen-ph hep-th