Majorana neutrinos and μ-decay

The μdecay is analyzed as a tool to determine whether neutrinos are Majorana or Dirac particles, within the framework of the effective weak interaction Hamiltonian with the (V+-A) currents. If the CP-violating term n sub(μ).(p sub(e)xn sub(e)) is detected where n stands for the polarization vector, this observation indicates the following facts; the Majorana property of neutrino, the existence of the right-handed current, the non-zero mixing between electron- and muon-neutrinos and the non-zero CP-violating phases in the leptonic sector. Various characters of quantities such as energy spectrum and (p sub(e)xn sub(μ)).(p sub(e)xn sub(e)) for Majorana neutrinos are compared with those for Dirac neutrinos. It is argued that the complex phases intrinsic to the Majorana neutrino system are really the CP-violating phases. (author)