Expectation values of flavor-neutrino numbers with respect to neutrino-source hadron states --Neutrino oscillations and decay probabilities--

TL;DR

This paper uses quantum field theory to unify the description of neutrino-related processes, deriving expectation values of flavor-neutrino numbers and showing that standard oscillation formulas apply broadly, with some modifications to oscillation length.

Contribution

It provides a unified quantum field theoretical framework for neutrino decay and oscillation processes, deriving expectation values and confirming the applicability of standard oscillation formulas.

Findings

Old decay probability formulas are recovered due to small neutrino masses.

Oscillation formulas are valid regardless of neutrino production details.

Derived oscillation length differs from conventional formulas.

Abstract

On the basis of quantum field theory, we consider a unified description of various processes accompanied by neutrinos, namely weak decays and oscillation processes. The structures of the expectation values of flavor-neutrino numbers with respect to neutrino-source hadron state are investigated. Due to the smallness of neutrino masses, we naturally obtain the old (i.e. pre-mixing) formulas of decay probabilities. Together, it is shown that the oscillation formulas, similar to the usual ones, are applied irrespectively of the details of neutrino-producing processes. The derived oscillation formulas are the same in form as the usually used ones except for the oscillation length.