Electron and muon neutrinos

The aim of this paper is to emphasize the possibility of solving certain physical problems by studying effects due to free neutrinos not heretofore discussed. The corresponding experiments may turn out to be not feasible today; however, it seems to us that a discussion of them is no more premature that the discussion in its time of the antineutrino experiments from reactors. The question discussed is the possibility of deciding, in principle, whether the neutrino emitted in the π → μ decay νμ and the neutrino emitted in β decay (νμ are identical particles or not