# Can Oscillating Neutrino States Be Formulated Universally?

## TL;DR

This paper proposes a quantum field theoretical framework for neutrino oscillations, defining oscillating neutrino states as coherent superpositions of massive neutrinos, validated in the ultrarelativistic limit.

## Contribution

It introduces a universal formulation of neutrino oscillations using a BCS-like quantum field theory approach, unifying the description of neutrino states.

## Key findings

- Oscillating neutrino states are modeled as Bogoliubov quasiparticles.
- The framework validates standard flavor states and oscillation formulas in the ultrarelativistic limit.
- Neutrino vacuum is described as a condensate of massless neutrino pairs.

## Abstract

A standing problem in neutrino physics is the consistent and universal definition of oscillating neutrino states as coherent superpositions of massive neutrino states. This problem is solved in a quantum field theoretical framework of neutrino mixing developed in analogy with the Nambu--Jona-Lasinio model for the dynamical generation of nucleon masses. The massive neutrino states are Bogoliubov quasiparticles and their vacuum is a condensate of "Cooper pairs" of massless flavour neutrinos. Their superpositions as oscillating neutrino states have intrinsic quantum coherence by construction. In this quantization framework, the standard phenomenological flavour neutrino states and oscillation probability formula are validated in the ultrarelativistic approximation.