Decoherence in Neutrino Oscillation between 3D Gaussian Wave Packets

TL;DR

This paper extends the theoretical framework of neutrino oscillation decoherence by modeling neutrinos as 3D Gaussian wave packets, revealing how production and detection widths influence coherence and localization.

Contribution

It introduces a 3D Gaussian wave packet model for neutrino oscillation, generalizing previous 1D models and clarifying the roles of spatial widths in coherence and probability calculations.

Findings

Spatial widths additively affect coherence length and localization.

Inverse sum of widths governs momentum conservation.

Probability depends on ratio of reduced to total widths.

Abstract

There is renewed attention to whether we can observe the decoherence effect in neutrino oscillation due to the separation of wave packets with different masses in near-future experiments. As a contribution to this endeavor, we extend the existing formulation based on a single 1D Gaussian wave function to an amplitude between two distinct 3D Gaussian wave packets, corresponding to the neutrinos being produced and detected, with different central momenta and spacetime positions and with different widths. We find that the spatial widths-squared for the production and detection appear additively in the (de)coherence length and in the localization factor for governing the propagation of the wave packet, whereas they appear as the reduced one (inverse of the sum of inverse) in the momentum conservation factor. The overall probability is governed by the ratio of the reduced to the sum.