Remarks on the weak states of neutrinos

It is shown that the weak states which are used in the standard treatment of neutrino oscillations do not, in general, describe correctly the neutrinos produced and detected in weak-interaction processes. It is also shown that it is impossible to construct a Fock space of weak states. However, neutrino oscillations can be described by defining appropriate ‘‘weak-process states,’’ which are superpositions of mass eigenstates weighted by their transition amplitudes in the process under consideration. In the extreme relativistic limit, the weak-process states reduce to the usual weak states. Some numerical examples are given to illustrate the magnitude of nonrelativistic corrections to the standard results.