Neutrino Flavor States and the Quantum Theory of Neutrino Oscillations

TL;DR

This paper reviews the standard theory of neutrino oscillations, clarifies assumptions, and introduces a wave-packet model to better understand neutrino coherence and localization effects.

Contribution

It demonstrates that the flavor states are valid approximations and shows the equal-momentum assumption is unnecessary, providing a wave-packet model for neutrino oscillations.

Findings

Standard flavor states are accurate approximations.

Equal-momentum assumption is unnecessary.

Wave-packet model describes coherence and localization.

Abstract

The standard theory of neutrino oscillations is reviewed, highlighting the main assumptions: the definition of the flavor states, the equal-momentum assumption and the time = distance assumption. It is shown that the standard flavor states are correct approximations of the states that describe neutrinos in oscillation experiments. The equal-momentum assumption is shown to be unnecessary for the derivation of the oscillation probability. The time = distance assumption derives from the wave-packet character of the propagating neutrinos. We present a simple quantum-mechanical wave-packet model which allows us to describe the coherence and localization of neutrino oscillations.