The Mikheyev-Smirnov-Wolfenstein Effect in Moving Matter

Abstract

The Lorentz invariant formalism for description of neutrino flavour oscillations in moving matter is developed. It is shown that the matter motion with relativistic speed can sufficiently change the matter term in the neutrino effective potential. In the case of matter motion parallel to neutrino propagation, matter effects in neutrino flavour oscillations are suppressed. In the case of relativistic motion of matter in the opposite direction in respect to neutrino propagation, sufficient increase of effects of matter in neutrino oscillations is predicted. The effective neutrino flavour oscillation probability, effective mixing angle and oscillation length, as well as the MSW effect resonance condition for the case of moving matter are derived.