Time-to-Space Conversion in Neutrino Oscillations

We study the neutrino oscillation problem in the framework of the wave packet formalism. The neutrino state is described by a packet located initially in a region S (source) and detected in another region D at a distance R from S. We examine how the oscillation probability as a function of variable R can be derived from he oscillation probability as a function of time t, the latter being found by using the Schrödinger equation. We justify the known prescription t→R/c without referring to a specific form of the neutrino wave packet and only assuming the finiteness of its support. The effect of the oscillation damping at large R is revealed. For an illustration, an explicit expression for the damping factor is obtained using Gaussian packet.