Quantum Field Theory of Particle Oscillations: Neutron-Antineutron Conversion

TL;DR

This paper develops a quantum field theory framework for neutron-antineutron oscillations, modeling the vacuum as a condensate and defining quasiparticle states, providing a new canonical quantization approach analogous to BCS theory.

Contribution

It introduces a canonical quantization method for neutron-antineutron oscillations, linking vacuum condensates with particle mixing, and aligns with existing Lagrangian approaches.

Findings

The vacuum is a condensate of neutron-antineutron pairs.

Neutron and antineutron are quasiparticle states on the physical vacuum.

The approach can be extended to neutrino oscillations.

Abstract

We formulate the quantum field theory description of neutron-antineutron oscillations in the framework of canonical quantization, in analogy with the Bardeen--Cooper--Schrieffer (BCS) theory and the Nambu--Jona-Lasinio model. The physical vacuum of the theory is a condensate of pairs of {\it would-be neutrons and antineutrons} in the absence of the baryon-number violating interaction. The quantization procedure defines uniquely the mixing of massive Bogoliubov quasiparticle states which represent the neutron. In spite of not being mass eigenstates, neutron and antineutron states are defined on the physical vacuum and the oscillation formulated in asymptotic states. The exchange of baryonic number with the vacuum condensate engenders what may be observed as neutron-antineutron oscillation. The convergence between the present canonical approach and the Lagrangian/path integral approach to neutron oscillations is shown by the calculation of the anomalous (baryon-number violating) propagators. The quantization procedure proposed here can be extended to neutrino oscillations and, in general, to any particle oscillations.