  Quantum-mechanical calculations of transitions dynamics between the left- and
right-handed helicity states of the atmospheric muon Dirac neutrino,which has a
gravitoelectrical dipole moment (GEDM) interacting with the gravitational field
of the Earth have been carried out. It is shown that the asymmetry of the
zenith-angle distribution of an atmospheric muon neutrino can be explained by
the interference of two mutually perpendicular plain-wave neutrino states
having different velocites inside the Earth in the presence of its gravitation
field. The deficit of the solar neutrino can also be explained by the electron
neutrino helicity flip transition due to the interaction of its GEDM with the
gravitation field of the Sun. The characteristic mass for the gravitational
dipole of the neutral and charged leptons have been estimated.
