Neutrino Oscillation Measurements Computed in Quantum Field Theory

TL;DR

This paper develops a quantum field theory approach to neutrino oscillations, revealing new insights into emission timing and implications for long-baseline damping, while aligning with standard formulas under typical experimental conditions.

Contribution

It introduces a quantum field theory framework for neutrino oscillations that accounts for emission timing differences and challenges the traditional wave packet interpretation.

Findings

Standard oscillation formula recovered in appropriate limits

Dominant contributions involve different emission times for mass eigenstates

Implications for damping mechanisms in long-baseline experiments

Abstract

We perform a calculation in quantum field theory of neutrino oscillation probabilities, where we include simultaneously the source, detector, and neutrino fields in the Hamiltonian. Within the appropriate limits associated with current neutrino oscillation experiments, we recover the standard oscillation formula. On the other hand, we find that the dominant contributions to the amplitude are associated with different neutrino mass eigenstates being emitted at different times, such that they arrive at the detector at the same time. This is contrary to the neutrino wave packet picture, where they are emitted simultaneously and separate as they travel to the detector. This has direct consequences regarding the mechanisms that lead to a damping of neutrino oscillations for very long baselines. Our analysis also provides a pedagogical example of a measurement process in quantum mechanics.