  We investigate the causes of the curious property of neutrino oscillations of
looking as an interference between fully distinguishable particles. The sources
of this effect are identified as to be determined by the many particle nature
of space of states of the quantum field theory. It is firstly underlined that
in order to explain the observed oscillations, the neutrino subspace of states
should not be interpreted as the direct product of the three neutrinos Fock
spaces, which is equivalent to imposing a superselection rule. Further, it is
argued that the linear completion of such a direct product space of states
permits to describe the measured oscillations. Thus, the space of states of te
Standard Model (SM) should be interpreted as the linear completion of the
direct product of all the Fock spaces (boson or fermions ones) associated to
the distinguishable particles. Then, it follows that the neutrino oscillations
are determined as interference between independent particles, which are
generated by states being outside the direct product of the neutrino Fock
spaces. This interpretation seems to imply a large amount of interference
observations between distinguishable particles in Particle as well as in
Condensed Matter Physics. For seeking clearness, the discussion is done in the
framework of a simple Quantum Field Theory (QFT) model of two relativistic free
massive neutrinos.
