Production process dependence of neutrino flavor conversion

TL;DR

This paper analyzes how the lifetime of the production process affects neutrino flavor oscillations, showing that long-lived resonances lead to uniform conversion probabilities regardless of distance, impacting experimental sensitivities.

Contribution

It introduces a covariant wave-packet framework incorporating production process lifetime, revealing its significant influence on neutrino oscillation observations and experimental sensitivities.

Findings

Flavor oscillations are washed out for long-lived resonance production.

The effective baseline is determined by the resonance lifetime.

LSND's sensitivity to neutrino mass differences is two orders of magnitude higher.

Abstract

We perform a covariant wave-packet analysis of neutrino oscillations taking into account the lifetime of the neutrino production process . We find that flavor oscillations in space are washed out when the neutrinos are produced from long lived resonances - and what may be observed in appearance/disappearance experiments is a uniform conversion probability independent of distance. The lifetime of the resonance which produces the neutrinos acts as the the effective baseline of the experiment. For this reason the LSND experiment where neutrinos are produced from muon decay has two orders of magnitude more sensitivity to neutrino mass square difference than other experiments where the neutrinos are produced from pion or kaon decays.