2020/12/10 by Winfried A. Mitaroff, W.A. Mitaroff, Mitaroff, Winfried A.
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Neutrino Physics Research #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.48550/arxiv.2012.05807
6 pages
arxiv created 2020/12/10 · openalex publication_date 2020/12/10 · arxiv updated 2020/12/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The phenomenology of massive neutrinos -- flavour mixing in the lepton sector causing oscillations between different neutrino-types along their propagation over macroscopic distances in vacuum -- aims at relating observable quantities (oscillation frequency or, equivalently, oscillation length) to the neutrino properties: mixing angles θij and mass-squared differences Δmij2. Calculation of the probabilities for a given neutrino-type either to survive or to mutate into another type, as functions of momentum p and travelling distance L, are properly based on wave-packet models of varying complexity. Approximations neglecting subtle effects like decoherence result in the standard oscillation formulae with terms proportional to sin2(Δmij2 L / 4 p). The same result may also be derived by a simple plane-wave model as shown in most textbooks. However, those approaches rely on unphysical a-priory assumptions: either "equal energy" or "equal velocity" or "equal momentum" in the phases of different mass eigenstates -- which are refuted elsewhere. In addition, some assume tacitly that interference occurs at time t = L. This study re-examines the plane-wave model. No unphysical assumption is necessary for deriving the standard formulae: a heuristic approach relies only on carefully defining interference at time t = L / β, and is justified by coherence arguments based in a qualitative way on wave-packets.